Method for preparing fiber-containing particles with regenerated reinforced fibers

Abstract

Recycled discontinuous carbon fibers are treated by rotary tumbling in a mixture with a binder material to prepare fiber-containing aggregates. Pretreatment options may include alignment of recycled discontinuous fibers in the recycled discontinuous fiber feed, length reduction treatment of the aligned discontinuous fibers, and fiber size classification to remove excessive discontinuous fibers before tumbling. Posttreatment may include size classification of the aggregates and retreatment of excessive aggregates.

Description

[Technical Field]

[0001] The present invention relates to processing reinforcing fibers, particularly recycled carbon fibers, into fiber-containing particles. This processing includes a method for preparing the particles, a bulk product comprising the particles, and a method for using them to prepare fiber-reinforced composite materials. [Background technology]

[0002] (cross reference) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 463,813, “Method for preparing fiber-containing particles using recycled reinforced fibers,” filed 3 May 2023, all portions of which are incorporated herein by reference for all purposes.

[0003] This application also incorporates, for all purposes, all portions of the following applications by reference: U.S. Patent Application No. 17 / 674,089, filed February 22, 2022 (corresponding Patent Document 1 has been issued), "Method for Manufacturing and Using Bulk Products comprising Fiber-Containing Particles Having a Dual Tapered Shape"; U.S. Patent Application No. 18 / 222,380, filed July 14, 2023 (corresponding Patent Document 2 has been issued), "Fiber-Containing Particles Having a Dual Tapered Shape"; and International Patent Application No. PCT / US2021 / 057389, filed October 29, 2021 (corresponding Patent Document 3), "Fiber-Containing Particles Having a Dual Tapered Shape".

[0004] Carbon fibers and other fibers are used in a variety of reinforcing applications, providing enhanced material properties by combining fibers with a matrix (often a polymer matrix) to reinforce the matrix material. Fiber-reinforced polymer composites are commonly referred to by the acronym FRP, and carbon fiber reinforced polymer composites by the acronym CFRP. The commercial value of reinforcing fibers, as well as environmental and landfill considerations, have generated significant interest in developing treatments for recovering and reusing reinforcing fibers. This is especially true for carbon fibers, as virgin carbon fibers are expensive. A considerable amount of CFRP produced (manufactured) becomes waste without being used. For example, in CFRP applications, material trimmings and scrap disposals commonly amount to more than 30% of the finished part weight. Furthermore, as the use of CFRP products has increased rapidly in recent years, the need to address end-of-life issues for CFRP products is expected to increase rapidly.

[0005] CFRP composite materials come in various forms and compositions as supplies for recycling. Some CFRP composite materials available for recycling are in the form of prepregs, which have a thermosetting polymer resin matrix, while others are in the form of cured products, where the thermosetting polymer resin has cured to form a cross-linked matrix. Furthermore, other CFRP composite materials available for recycling use thermoplastic polymers as a matrix, and new CFRP composite materials are being developed using engineering polymers that cannot be clearly classified as either thermoplastic or thermosetting.

[0006] Various processing methods have been developed and are still under development to free carbon fibers from the matrix in CFRP products and to recover the freed fibers for recycling. Some processing techniques for freeing carbon fibers from the matrix are sometimes called pyrolysis, which involves exposing the CFRP to high temperatures, typically in an oxygen-free or oxygen-limited environment, to decompose the matrix into gaseous and / or liquid decomposition products without destroying the carbon fibers. Other processing techniques are sometimes called depolymerization techniques, which involve reacting the matrix material with chemicals to decompose it into decomposition products and separate the fibers from the decomposition products. Still other processing techniques are sometimes called solubolisis techniques, which involve dissolving the matrix material with a solvent and freeing the fibers for recovery. These techniques are sometimes used in combination.

[0007] Virgin carbon fibers are typically prepared in the form of continuous fiber strands, but most recycled carbon fibers, both now and in the future, are supplied primarily in the form of discontinuous, relatively short fibers, and the alignment of the fibers and the entanglement of individual fibers are expected to be significantly random. One common technique for preparing virgin carbon fibers for incorporation into CFRP composites is to prepare bundles of parallel continuous fiber strands, such as in the form of a fiber tow, and then cut these continuous bundles to the desired length to form pellets. The fibers may be held in place by fiber sizing applied to the bundles beforehand (e.g., sized tows). Pellets prepared by chopping fiber tow bundles are sometimes called chopped tow pellets. Such pellets can be prepared in sizes and shapes convenient for feeding into a compound extruder, for example, from a hopper to a side feeder of a twin-screw extruder. A typical side feeder has a feed screw that actively pushes the pellets into the polymer molten material in the extruder barrel. Extrusions containing polymers and carbon fibers are then cooled and cut into pellets of CFRP material. These pellets can be used in various applications, such as injection molding, to prepare a variety of product forms made from CFRP composite materials. The ability to process virgin carbon fibers in the form of continuous fiber strand bundles allows for precise processing control to prepare pellets with uniform size and composition, good fluidity during bulk handling, and good dispersibility in the polymer melt during compounding. However, these techniques for processing virgin carbon fibers are generally not applicable to the processing of the vast majority of recycled carbon fibers, which are in a discontinuous form after being recovered during recycling operations and tend to have significantly random alignment and entanglement of carbon fibers.

[0008] Furthermore, the feedstock for recycled carbon fiber can exhibit significant variability in its properties. Unlike the controlled supply quality of virgin carbon fiber, the feedstock for recycled carbon fiber can show high variability. This can be due to differences in the composite waste or scrap from which the recycled carbon fiber is recovered, the processing technologies used to recover the carbon fiber from such composite waste or scrap, and the handling of the recycled carbon fiber after recovery. Consequently, the feedstock for recycled carbon fiber can vary considerably in terms of the degree of randomness in fiber alignment, the degree of fiber bending, bundling, and entanglement, and the degree of variation in fiber length.

[0009] Therefore, there is a strong need for new, more versatile technologies to replace the technologies used for processing virgin carbon fiber raw materials. These technologies should enable the preparation of CFRP composite materials using a wide range of highly variable recycled carbon fiber raw materials. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] U.S. Patent No. 11787085 [Patent Document 2] U.S. Patent No. 11951656 [Patent Document 3] International Publication No. 2023 / 075795 [Patent Document 4] U.S. Patent No. 10487191 [Patent Document 5] Strength Specification No. 10610911 [Patent Document 6] U.S. Patent No. 10829611 [Overview of the project] [Problems that the invention aims to solve]

[0011] As mentioned above, recycled carbon fibers are usually recovered as relatively short, discontinuous fibers, resulting in high randomness in fiber alignment, significant entanglement between fibers, and a tendency to form cotton ball-like clumps. Therefore, conventional equipment and technologies designed for fluid powders and other bulk materials are ineffective for handling and processing them. For example, recycled carbon fibers tend to form bridges by solidifying into clumps, which obstructs the flow from the hopper to the feeder of the compound extruder.

[0012] Conventional pellet grinding methods were attempted to prepare masterbatch pellets by mixing recycled carbon fibers with polymers, but the success was limited. With recycled carbon fibers, good compounding with polymers was only possible when the fibers were ground to approximately 150 microns in size, and even then, the resulting masterbatch pellets were only slightly functional. As is understood, longer fibers with higher aspect ratios are desirable for improving performance as polymer reinforcements. However, masterbatch pellets made using even longer recycled fibers were found to have poor mechanical performance in polymer compounds. These pellets were too dense, preventing effective defibration and dispersion of carbon fibers during extrusion to form CFRP composite materials, resulting in uneven fiber density in the injection-molded test articles. [Means for solving the problem]

[0013] The methods and products disclosed herein are intended to address, at least partially and significantly, the problems associated with incorporating recycled carbon fibers into CFRP composites and with manufacturing molded products from such CFRP composites. While the methods and products disclosed herein are primarily described in relation to carbon fibers, the disclosure is also applicable to other reinforcing fibers and other recycled fibers. Furthermore, the methods and products disclosed herein are also applicable to the processing of virgin fibers that are processed in relatively short fiber forms rather than continuous forms. Such discontinuous virgin fibers may be a direct result of the manufacturing process or fibers cut from continuous fiber strands. The methods and products disclosed herein are particularly advantageous when preparing fiber-reinforced polymers using recycled fibers, such as recycled carbon fibers, which are typically recovered in discontinuous fiber forms and have a high degree of randomness in fiber alignment and entanglement, makes subsequent processing of the recycled fibers difficult.

[0014] It has been found that recycled reinforcing fibers (such as carbon fibers), which have a high degree of randomness in the longitudinal alignment of the fibers, can be processed into aggregates with a particulate structure (hereinafter referred to as "aggregates") by a process that involves tumbling discontinuous recycled fibers in a processing mixture containing a binder material. Typically, a controlled amount of liquid (such as water) is also included, and the process is carried out until aggregates are formed during tumbling. The aggregates can then be recovered and further processed to prepare the final fiber-containing particles. Typically in a dry particle form, these become a high-quality bulk product suitable as a feed for preparing fiber-reinforced composites using recycled reinforcing fibers in polymer compound applications.

[0015] This process can be advantageously used to prepare fiber-containing particles in which reinforcing fibers are bonded in an elongated particle structure, and many particles can be advantageously prepared to have a dual-taper (double taper) shape. Such fiber-containing particles comprise, for the majority of the weight, preferably from 90 weight percent to 99.5 weight percent, of reinforcing fibers, and for a minor part of the weight, preferably from 0.5 weight percent to 10 weight percent, of a binder that holds the reinforcing fibers in the particle structure, and a particle length dimension preferably in the range from 3 millimeters to 40 millimeters (the maximum separation (isolation, separation, distancing, separation) distance in the longitudinal direction between the first longitudinal end and the second longitudinal end of the fiber-containing particle), and a maximum particle width dimension orthogonal (transverse) to the longitudinal direction at a longitudinal position between the first longitudinal end and the second longitudinal end, and an aspect ratio equal to the value obtained by dividing the particle length dimension by the maximum particle width dimension, which is greater than 1, preferably at least 1.5, and may include.

[0016] Furthermore, many elongated particles can be advantageously prepared to have a dual-taper shape with a first tapered portion that tapers in a direction away from the longitudinal position towards the first longitudinal end, and a second tapered portion that tapers in a direction away from the longitudinal position towards the second longitudinal end, and are provided with.

[0017] Such fiber-containing particles, prepared using recycled carbon fibers and possessing a dual tapered shape, have been found to enhance the flowability of bulk products containing these particles when fed into a compound extruder via an extrusion feeder (feed) supplied from a conventional hopper (e.g., a vibrating loss-in-weight hopper). This makes it possible to prepare carbon fiber-reinforced polymer composites in which carbon-reinforced fibers provided by the fiber-containing particles are dispersed within the polymer matrix. The fiber-containing particles offer a favorable combination of moderate flowability in handling bulk products and sufficient particle integrity during normal handling and processing operations until passing through the feed hopper during the compounding operation. Subsequently, the particle structure degrades due to shearing applied in the side screw feeder and polymer melt during extrusion, providing an extruded product in which reinforcing fibers are moderately dispersed within the extruded polymer. The dual tapered particle structure allows for the promotion and incorporation of fibers of various lengths into the fiber-containing particles for beneficial use in fiber-reinforcement applications. Furthermore, the dual tapered shape is characterized by significant alignment of fibers in the longitudinal direction of the fiber-containing particles, which is thought to greatly contribute to improved fluidity in bulk product form and improved dispersibility of fibers from particles to polymer melt in polymer blends for preparing fiber-reinforced polymer composite materials. Achieving such significant fiber alignment greatly reduces the randomness of fiber alignment, thereby reducing fibers protruding perpendicularly to the longitudinal direction from the fiber-containing particles and reducing entanglement between particles, which can impair the fluidity of bulk products. Rather, the dual tapered shape and the remarkable alignment of fibers in the longitudinal direction of the fiber-containing particles promote the sliding of fiber-containing particles in bulk products, even when fiber-containing particles with the dual tapered shape are mixed with other particles in bulk products, contributing to fluidity and generally imparting sliding properties to the bulk product.Regarding the dispersibility of fibers into the polymer melt in a polymer compound, the significant alignment of fibers in the dual-tapering shape of fiber-containing particles promotes the reduction of entanglement of fibers when the particles deteriorate in the polymer compound, and also promotes, for example, the improvement of the dispersibility of fibers into the polymer melt of the polymer compound in an extruder.

[0018] The fiber-containing particles prepared by the method of the present disclosure are advantageously used to prepare bulk products comprising multiple fiber-containing particles, preferably a portion of the bulk product, more preferably a large portion, comprising fiber-containing particles having a dual tapered shape. Such bulk products may or may not contain other particles in addition to the fiber-containing particles having a dual tapered shape. Such other particles may include other elongated fiber-containing particles prepared together with the dual tapered particles from the aggregates of the present disclosure, but lacking the development of a dual tapered shape. The bulk product may consist only of, or substantially only of, fiber-containing particles from aggregates prepared together during the tumbling process. Alternatively, the bulk product may include other particles not prepared during the tumbling process, for example, particles mixed with the fiber-containing particles after the fiber-containing particles from aggregates formed during tumbling have been prepared. The blended particles may or may not contain fibers, and if such blended particles contain fibers, those fibers may be of the same type (e.g., carbon fibers) or different type from the fibers of the fiber-containing particles prepared from the tumbling aggregates. For example, fiber-containing particles prepared from aggregates may be mixed with conventional chopped tow pellets or other fiber-containing pellets. In some preferred embodiments, the bulk product of this second aspect comprises a majority (more than 50 weight percent) or even greater proportion of fiber-containing particles having a dual tapered shape by weight. When referring to a bulk product comprising multiple fiber-containing particles having a dual tapered shape, the properties described for those fiber-containing particles apply to the fiber-containing particles having a dual tapered shape in the bulk product, while not necessarily applying to other particles in the bulk product that do not have a dual tapered shape. As described above, bulk products containing fiber-containing particles with a dual tapered shape offer an advantageous combination: improved fluidity during handling before compounding, and enhanced dispersibility of reinforcing fibers from the particles into the polymer melt when compounding the fibers with the polymer matrix during extrusion.

[0019] As described above, the method of this disclosure provides for the production of fiber-containing particles comprising recycled reinforcing fibers, preferably many of which have a dual tapered shape, and comprises the step of tumbling a mixture of reinforcing fibers (e.g., recycled carbon fibers) and a binder material to form aggregates comprising the reinforcing fibers and the binder material. Such aggregates may be recovered as fiber-containing particles into a bulk product, or they may be further processed to prepare a final form, typically in the form of dry particles, and constitute a high-quality bulk product suitable as a feed for polymer compounds for preparing fiber-reinforced composite materials using recycled reinforcing fibers. When the reinforcing fiber feed comprises discontinuous reinforcing fibers, a method for preparing fiber-containing particles comprising fibers from the fiber feed by processing the fiber feed and the binder material to produce fiber-containing particles is provided. The process may include a step of forming aggregates, each comprising a portion of the reinforcing fibers and a portion of the binder material, by tumbling a mixture of reinforcing fibers and a binder material, preferably by rotary tumbling.

[0020] As can be understood, fiber-containing particles obtained by this method do not possess the extremely high uniformity of size, shape, and fiber alignment found in conventional chopped-tow pellets produced by processing bundles of continuous virgin fibers. Surprisingly, tumbling can be advantageously used to produce batches of fiber-containing aggregates, many, and even most, of which develop the desired dual tapered shape and have significant longitudinal alignment of fibers relative to the longitudinal direction of the aggregate. During rotational tumbling, the very random fiber alignment (and fibers of varying lengths) in the feed of regenerated fibers is transformed into a much more aligned fiber arrangement, and the more aligned fibers are incorporated into aggregates having a dual tapered shape. Such aggregates may be recovered for use as fiber-containing particles and in bulk products, or may be further processed to prepare final fiber-containing particles, preferably retaining largely the dual tapered morphology of the dual tapered aggregates with significantly aligned fibers. Such further processing may include, for example, drying to improve particle integrity by removing residual processing liquid (typically water) and to remove liquids that may volatilize harmfully at the high polymer melting temperatures encountered during polymer extrusion in compounding. Such further processing may include other processing described below.

[0021] While tumbling can be used to prepare high-quality fiber-containing particles with properties favorable to bulk products used as feedstock for polymer compounds (e.g., extrusion) using recycled reinforced fibers, the yield of fiber-containing particles suitable for inclusion in such bulk products is relatively low, at around 60 percent, due to the non-uniform length and highly random longitudinal alignment of the recycled reinforced fibers. Off-spec aggregates unsuitable for preparing particles for such bulk products often contain oversized fibers with lengths outside the desired range, and such oversized fibers pose a problem in preparing bulk products suitable for polymer compound feedstocks. One problem with the presence of oversized fibers is that some oversized aggregates form during tumbling, and these are too long for polymer compound feeding in conventional equipment. Another problem with the presence of oversized fibers is that they tend to protrude from the particle structure of the aggregates, resulting in a detrimental reduction in the bulk density and flowability of the resulting bulk product, and potentially causing blockages and bridging in polymer compound feeding. As a result, producing high-quality bulk products suitable for polymer compound supply requires classification and removal of oversized aggregates after tumbling, thus reducing the yield of bulk products suitable for polymer compounding from the recycled reinforced fiber feed. However, the presence of "fuzzy" aggregates, where strands of oversized fibers protrude from the particle structure, still negatively affects the bulk density and flowability of the resulting bulk powder. While many of these "fuzzy" aggregates can be removed by visual sorting, such processing increases costs and further reduces yield. Furthermore, since the removed aggregates are retained in the particle structure by the binder material and liquid (typically water) in the initial treatment mixture subjected to tumbling, alternative uses for the off-spec aggregates are limited, and attempting to separate the reinforced fibers from the binder material and liquid in a useful manner is impractical and costly. The liquid can be removed by drying, but in that case, the particle structure of the dried aggregates hardens, further complicating attempts to separate the reinforced fibers from the binder material.These problems are exacerbated by the high variability in different recycled reinforced fiber supplies. This is because processing modifications made to address problems with one type of supply do not necessarily provide the versatility to effectively and efficiently process other types of recycled reinforced fibers, as their characteristics can vary significantly, as mentioned above.

[0022] The various improvements in the processing of recycled reinforced fibers disclosed herein address these problems. For example, by reducing the amount of problematic over-reinforced fibers in the feed for aggregate formation by tumbling, and by reprocessing off-spec aggregates (e.g., over-reinforced aggregates and "fuzzy" aggregates), the versatility in processing various recycled reinforced fiber feeds having different feed characteristics is improved. Three important processing improvements are disclosed here, each of which can be used beneficially alone, but preferably in synergistic combination to more effectively reduce problems associated with the variability of recycled reinforced fiber feeds and the potential for complications from the introduction of over-reinforced fibers into the tumbling process, as well as improving the yield and quality of bulk products suitable for use as polymer compound feeds. These improvements can significantly increase the yield of aggregates suitable for preparing bulk products for use as polymer compound feeds, sometimes reaching over 90 percent, and enable more versatile application to a variety of different recycled reinforced fiber feeds.

[0023] The first aspect of this disclosure relates to a method for manufacturing a bulk product comprising fiber-containing particles in which reinforcing fibers are held in the particle structure by a binder. The method is A step of preparing a discontinuous fiber feed for discontinuous reinforcing fibers by pre-treating reinforcing fibers, preferably recycled reinforcing fibers (e.g., recycled carbon fibers), A step of preparing an aggregate comprising discontinuous reinforcing fibers of at least a portion of a discontinuous fiber feed and a binder material, wherein the step of preparing the aggregate comprises combining the discontinuous fiber feed and the binder material in a process mixture and tumbling the process mixture, It is equipped with, The aforementioned preliminary treatment is A step of preparing a plurality of fiber fractions comprising at least a first fiber fraction and a second fiber fraction by size classifying a mixture of discontinuous reinforced fibers, wherein the first fiber fraction has a first weight-average fiber length, the second fiber fraction has a second weight-average fiber length, and the second weight-average fiber length is greater than the first weight-average fiber length, A step of preparing a discontinuous fiber feed such that it comprises at least a portion of the discontinuous reinforcing fibers of the first fiber fraction, It is equipped with.

[0024] One advantage of this size classification of reinforcing fibers is that it significantly reduces the number of excess fibers ultimately introduced into the tumbling mixture, which is achieved before the reinforcing fibers are mixed with the binder and liquid to form the tumbling mixture. This promotes the formation of aggregates of more uniform size. Long reinforcing fibers in the second fiber fraction can be advantageously diverted to alternative treatments without the additional complexity of being included in the mixture with the binder and liquid. Such alternative treatments may be directed, for example, to the preparation of an alternative product, and more preferably, may involve shortening the fiber length within the second fiber fraction (e.g., cutting the fibers), followed by treating the shortened fibers by tumbling and preparing aggregates.

[0025] A second aspect of this disclosure relates to a method for manufacturing a bulk product comprising fiber-containing particles in which reinforcing fibers are held in the particle structure by a binder. The method is A step of preparing a discontinuous fiber supply of discontinuous reinforcing fibers by pre-treating reinforcing fibers, preferably recycled reinforcing fibers (e.g., recycled carbon fibers), A step of preparing an aggregate comprising discontinuous reinforcing fibers of at least a portion of a discontinuous fiber supply and a binder material, wherein the step of preparing the aggregate comprises a step of combining the discontinuous fiber supply and the binder material in a processing mixture and a step of tumbling the processing mixture, It contains, The aforementioned preliminary treatment is The process involves preparing an aligned fiber feed by increasing the longitudinal alignment between reinforcing fibers, A step of preparing a discontinuous fiber feed such that it comprises at least a portion of the reinforcing fibers of the aligned fiber feed, It is equipped with.

[0026] One of the advantages of such fiber alignment is that it improves the uniformity of the recycled reinforced fiber feed, enhances the uniformity of the process for preparing aggregates, and makes it applicable to various recycled reinforced fiber feeds. For example, the fibers in such aligned fiber feed can be shortened (e.g., cut) to prepare cut fibers with significantly less variation in fiber length before mixing the fibers with the binder and liquid to prepare the tumbling mixture. A more uniform fiber length in the tumbling mixture contributes to the formation of aggregates of a more uniform size, even for various different reinforced fiber feeds.

[0027] A third aspect of this disclosure relates to a method for producing a bulk product comprising fiber-containing particles in which reinforcing fibers are held in the particle structure by a binder. The method is Production processing is a manufacturing process, and production processing is, (i) A step of preparing an aggregate, the step of preparing an aggregate comprising: tumbling a treatment mixture comprising discontinuous reinforcing fibers (preferably recycled reinforcing fibers, such as recycled carbon fibers) and a binder material; and forming an aggregate comprising at least a portion of the discontinuous reinforcing fibers and at least a portion of the binder material, wherein the aggregate is The particle length dimension is the maximum separation distance in the longitudinal direction between the first and second longitudinal ends of the aggregate, and At the longitudinal position between the first longitudinal end and the second longitudinal end, the maximum particle width dimension perpendicular to (crossing) the longitudinal direction, and An aspect ratio equal to the value obtained by dividing the particle length dimension by the maximum particle width dimension, A step of preparing aggregates having a particle structure comprising, (ii) A step of preparing multiple aggregate fractions by subjecting aggregates to size classification, wherein the multiple aggregate fractions comprise at least a first aggregate fraction and a second aggregate fraction, the first aggregate fraction having a first weight-average particle length dimension, the second aggregate fraction having a second weight-average particle length dimension, and the first weight-average particle length dimension being smaller than the second weight-average particle length dimension, (iii) A step of processing at least a portion of the aggregates of the first aggregate fraction to provide fiber-containing particles having a particle structure for inclusion in a bulk product, Manufacturing processes that include, A reprocessing step is performed with respect to at least one of the second aggregate fractions prepared by the manufacturing process, wherein the reprocessing step involves reprocessing at least a portion of the discontinuous fibers and binder material of the second aggregate fraction, and the reprocessing step is performed by: (a) A step of preparing reprocessed discontinuous reinforced fibers by subjecting at least a portion, preferably all, of the aggregates of the second aggregate fraction to a length reduction process, thereby reducing the length of at least a portion of the discontinuous reinforced fibers of the second aggregate fraction, wherein the length reduction process optionally comprises a step of subjecting at least a portion of the second aggregate fraction to one or more cutting operations, (b) A process of subjecting the processing mixture of the manufacturing process at the time of the reprocessing occurrence to the manufacturing process at the time of the reprocessing occurrence, including at least a portion of the reprocessed discontinuous reinforced fibers from the second aggregate fraction and at least a portion of the binder material from the second aggregate fraction. A reprocessing process is provided, It includes.

[0028] It has been found that reinforcing fibers in excessive aggregates can be successfully reprocessed to produce smaller aggregates, thus enabling the acquisition of a more uniform bulk product in higher yields. This is achievable even with the additional complexity of the fibers being mixed with the binder and liquid in the excessive aggregates. In a particularly advantageous example, the excessive aggregates in the second aggregate fraction can be subjected directly to a fiber length reduction treatment without separating the fibers from the binder and liquid, and then subjected to tumbling again to prepare smaller aggregates. As a result, a high-quality bulk product with a more uniform particle size can be obtained in higher yields from the initial feed of regenerated reinforced fibers.

[0029] A fourth aspect of this disclosure relates to a method for making fiber-reinforced composites. The method comprises dispersing reinforcing fibers into a matrix from fiber-containing particles, for example, from fiber-containing particles in a bulk product manufactured by the methods of the first, second, or third aspects. Such a fiber-reinforced composite may be a fiber-reinforced polymer, where the matrix is ​​a polymer material. If the matrix is ​​a polymer material, the method of the fourth aspect may include compounding the reinforcing fibers from the fiber-containing particles with a matrix polymer, for example by extrusion, in which case the fibers are dispersed in a polymer melt in an extruder. The extruded product having the reinforcing fibers dispersed in a polymer matrix is ​​pelletized, and the pellets can be used to prepare a molded product in a molding process, for example, injection molding. Such pellets may be used directly as a feed for molding (preferably injection molding), or they may be used as a masterbatch and further compounded and diluted with a suitable polymer to prepare a final fiber-reinforced polymer composition having a desired fiber-filling level lower than that in the masterbatch, which is then used as a feed for molding, preferably injection molding.

[0030] These and other aspects are further described in the following description, the accompanying claims, and the drawings. A number of further characteristic improvements and additional features are applicable to these aspects, and these characteristic improvements and additional features may be used individually or in any combination in the subject matter of the first aspect or any other aspect of the present disclosure. Thus, each feature described in the following description (including combinations of numbered embodiments and the accompanying claims), and / or each feature illustrated in the drawings may, but is not required to be, used in conjunction with other features or combinations of features of any aspect of the present disclosure. [Brief explanation of the drawing]

[0031] [Figure 1]This figure shows the characteristics of an example of fiber-containing particles having a dual tapered shape as disclosed herein. [Figure 2] This figure shows the features of another example of fiber-containing particles having a dual tapered shape as disclosed herein. [Figure 3] A schematic process diagram illustrating several exemplary processes for producing the fiber-containing particles of this disclosure. [Figure 4] This is a schematic diagram showing the internal baffles within a rotatable processing container, illustrated in the form of a rotating drum. [Figure 5] A schematic process diagram showing some exemplary optional preliminary processes in the general process of Figure 3. [Figure 6] A schematic process diagram showing several exemplary arbitrary post-processing steps in the general process shown in Figure 3. [Figure 7] A schematic process diagram illustrating several exemplary processes comprising the preparation of the bulk product of this disclosure. [Figure 8] Schematic process diagrams showing several exemplary arbitrary composite material preparation processes in the general process shown in Figure 7. [Figure 9] Schematic process diagrams showing several exemplary arbitrary recycling processes that provide a preliminary supply of fibers in a general process shown in Figure 7. [Figure 10] This is a photographic image showing an example of a recycled carbon fiber supply, where the recycled carbon fibers exhibit a high degree of randomness in their alignment within a cotton ball-like structure. [Figure 11] These photographic images show two different exemplary batches of fiber-containing particles made from recycled carbon fibers, each prepared from recycled carbon fibers cut to different lengths and producing fiber-containing particles of different sizes. [Figure 12] This is a photographic image showing a bulk product with an exemplary batch of fiber-containing particles in a beaker. [Figure 13] A photographic image of the bulk product shown in Figure 12, viewed from above. [Figure 14] A photographic image of fiber-containing particles showing well-developed dual tapered shapes and aligned fibers along the longitudinal direction of the particles. [Figure 15] A photographic image showing the inside of a rotating drum containing aggregates made from recycled carbon fibers. [Figure 16] Partial perspective view of a vibrating conveyor deck equipped with alignment channels. [Figure 17] Partial perspective view of a vibrating conveyor deck assembly with alignment slots. [Figure 18] This figure shows an example of improving the alignment of reinforcing fiber groups with respect to the direction of fiber machine transport. [Figure 19] A diagram showing the longitudinal alignment of reinforcing fibers as an example, and the alignment angle with respect to the direction of fiber machine transport. [Figure 20] A schematic process diagram showing an example of the process during aggregate reprocessing. [Figure 21] A schematic process diagram showing an example of the manufacturing process during aggregate reprocessing. [Figure 22] This is a schematic flow diagram showing an example of a process for producing fiber-containing particles, which includes the recycling of substandard aggregates for reprocessing. [Figure 23] A schematic flow diagram illustrating an example of the preparation of a bulk product using fiber-containing particles, involving a four-step aggregate reprocessing process. [Modes for carrying out the invention]

[0032] The features shown in the drawings are illustrated to aid in the description and understanding of features applicable to various aspects of this disclosure, and the features shown in the drawings do not necessarily need to be to scale or to be detailed in every respect.

[0033] Figure 1 shows the characteristics of several fiber-containing particles having a dual tapered shape according to the present disclosure. As shown in Figure 1, the fiber-containing particle 100 has an elongated form having a first longitudinal end 102 and a second longitudinal end 104, with a longitudinal direction 106 between the two ends (102, 104). The longitudinal direction 106 generally coincides with the longitudinal axis of the fiber-containing particle 100. However, it should be understood that fiber-containing particles like the fiber-containing particle 100 are generally not symmetrical with respect to such a longitudinal axis. This is because, although the fiber-containing particles of the present disclosure have elongated characteristics, they are not perfectly symmetrical with respect to the central axis as a result of the manufacturing method. The fiber-containing particle 100 has a particle length dimension 108, which is the straight-line distance between the first longitudinal end 102 and the second longitudinal end 104. To be understood, the particle length dimension 108 represents the maximum separation distance in the longitudinal direction 106 between the first longitudinal end 102 and the second longitudinal end 104. Furthermore, the fiber-containing particle 100 has a maximum particle width dimension 110 that is perpendicular to the longitudinal direction 106. The maximum particle width dimension 110 represents the maximum separation distance between opposing surfaces of the fiber-containing particle 100 on a line that transverses the longitudinal direction 106. The fiber-containing particle 100 has an aspect ratio equal to the value obtained by dividing the particle length dimension 108 by the maximum particle width dimension 110. The fiber-containing particle 100 illustrated in Figure 1 further has a dual tapered shape, and the first tapered portion 112 tapers along the longitudinal direction 106 from the longitudinal position 114 of the maximum particle width dimension 110 toward the first longitudinal end 102. The second tapered portion 116 tapers along the longitudinal direction 106 from the longitudinal position 114 toward the second longitudinal end 104.

[0034] Figure 2 also illustrates the characteristics of the fiber-containing particle having a dual tapered shape according to the present disclosure. As shown in Figure 2, the fiber-containing particle 140 comprises a first longitudinal end 142, a second longitudinal end 144, a longitudinal direction 146, a particle length dimension 148, a maximum particle width dimension 150 at a longitudinal position 154, a first tapered section 152, and a second tapered section 156. Figure 2 shows that the first tapered section 152 tapers over a portion of the particle length dimension within a tapered envelope of a right-circular cone 158 having an opening (cone angle) α whose apex coincides with the first longitudinal end 142. Similarly, the second tapered section 156 tapers over a portion of the particle length dimension within a tapered envelope of a right-circular cone 162 having an opening (cone angle) β whose apex coincides with the second longitudinal end 144. As can be understood, the shape of fiber-containing particles obtained by the manufacturing method of the present disclosure is generally asymmetrical, so the opening α of the right-circular cone envelope of the first tapered section is usually different from, but often takes a relatively close value to, the opening β of the right-circular cone envelope of the second tapered section. Also, as shown in Figure 2, the fiber-containing particles having a dual tapered shape of the present disclosure do not need to tape continuously from the position of the maximum particle width dimension toward each of the first and second longitudinal ends of the particle. In this regard, the fiber-containing particle 140 illustrated in Figure 2 has a local minimum width 166 and a local maximum width 168 occurring in the longitudinal direction 146 between the maximum particle width dimension 150 and the second tapered section 156. Furthermore, as can be understood, neither the first tapered section 152 nor the second tapered section 156 of such a dual tapered particle of the present disclosure needs to tape completely and continuously toward each of the longitudinal ends of the fiber-containing particle. For example, the fiber-containing particles 140 may include small portions that do not continuously taper near the first longitudinal end 142 or are not within the tapered envelope of the right cone 158, or small portions that do not continuously taper near the second longitudinal end 144 or are not within the tapered envelope of the right cone 162. As can be understood, small bundles of fiber ends may occur near the first longitudinal end 142 and / or the second longitudinal end 144, interrupting the taper of the first tapered section 152 and / or the second tapered section 156 near each longitudinal end (142, 144).

[0035] Figure 3 is a schematic process block diagram showing an exemplary process 200 for producing fiber-containing particles. The fiber-containing particles have reinforcing fibers held in the particle structure by a binder, and some or all of the fiber-containing particles preferably have a dual tapered shape as shown in Figures 1 and 2. Process 200 comprises tumbling 206 (preferably rotational tumbling) a mixture of reinforcing fibers from a fiber feed 202 and binder material 204, forming aggregates 208 containing the reinforcing fibers in an aligned state, generally aligned so as to extend longitudinally along the longitudinal direction of the aggregates. Rotary tumbling is typically carried out in a rotating drum or similar rotatable processing vessel containing a mixture of reinforcing fibers from the fiber feed 202 and binder material 204. The fiber feed 202 and binder material 204 may be added to the processing vessel in a single batch or in multiple batches, or they may be added individually or as a mixture or formulation with other materials. As an example, the binder material may be supplied in the form of a liquid suspension, in which case the binder material comprises particles suspended in a carrier liquid (typically an aqueous liquid). The fibers of the fiber supply 202 may be unsized fibers, such as unsized carbon fibers or other fibers. Alternatively, the fibers of the fiber supply 202 may be sized fibers, in which a thin layer of sizing material is coated over a base fiber structure (carbon fibers or other fibers). The sizing is typically a thin polymer coating that protects the base fiber structure (e.g., a carbon fiber structure) and / or functions as a compatibilizer to enhance the bonding and / or dispersibility of the fibers with the matrix material to which they are to be combined to prepare a fiber-reinforced composite material. If the fibers are sized fibers before being mixed with the binder material, the sizing is considered part of the fibers and part of the fiber component of the fiber-containing particles. In the case of sized fibers, the sizing is typically not more than 5% by weight of the fiber, preferably not more than 3% by weight, and more preferably not more than 2% by weight. Some or all of the fiber feed 202 and / or binder material 204 may be introduced into the processing container separately or as a mixture.The fiber feed 202 and / or binder material 204 may be introduced into the processing vessel before or during its rotation. The rotating vessel may be operated in batch mode, which means introducing corresponding batches of fiber feed and binder material into the vessel and performing tumbling 206 as batches, stopping the rotation of the vessel at the end of tumbling 206 of the batches and removing the aggregates as processed batches. Alternatively, the rotating vessel may be operated in continuous or semi-continuous mode, in which case the fiber feed 202 and binder material 204 are introduced continuously or semi-continuously into the upstream part of the rotating vessel, and the aggregates 208 are removed from the downstream part of the rotating vessel.

[0036] Important variables in the operation of tumbling 206 include the length of the fibers being processed, the amount of binder material used relative to the amount of fibers being processed, and the relative amount of liquid (typically water) mixed with the binder material and fibers in the mixture subjected to tumbling. In the case of rotary tumbling in a rotating vessel, additional variables include the tangential velocity (tip velocity) of the inner wall of the rotating vessel during tumbling, and whether the rotating vessel has internal baffles to promote a stronger tumbling action even at low tangential velocities. Generally, it has been found that the longer the average fiber length in the fiber feed, the larger the resulting fiber-containing particles. In many situations, the weight-average length of the reinforcing fibers in the fiber feed may range from 1 to 18 millimeters. The resulting fiber-containing particles often have a weight-average particle length dimension that is approximately 2 to 3 times the weight-average fiber length in the fiber feed subjected to tumbling. In particular, when producing fiber-containing particles for compounding with polymers in an extruder, the preferred weight-average particle length dimension of the fiber-containing particles is often less than approximately 14 millimeters for compatibility with many conventional compounding systems. Furthermore, it has been found that generally, increasing the proportion of binder material reduces the ability of fibers to disperse from the fiber-containing particles during polymer compounding. At some point, the amount of binder becomes excessive, preventing the fiber-containing particles from effectively degrading during polymer compounding and hindering the effective dispersion of reinforcing fibers. On the other hand, reducing the amount of binder material relative to the amount of fiber in the fiber feed subjected to tumbling compromises the particle integrity of the fiber-containing particles during handling. At some point, the amount of binder material becomes insufficient, making it impossible to maintain the desired particle integrity during the handling process before polymer compounding. Generally, the binder material is present in an amount ranging from approximately 0.5% to approximately 11% by weight relative to the fiber weight, which provides approximately 0.5% to approximately 10% by weight of binder in the final fiber-containing particles. Furthermore, generally speaking, an excess or deficiency of liquid (typically water) in the processing mixture during tumbling hinders the formation of fiber-containing aggregates with the desired size, shape, and particle integrity.Insufficient water volume prevents the material from binding properly during the flocculation process, meaning that most of the fibers remain as individual fibers. Excessive water creates large bundles in one or more dimensions (length, width, or volume), and at some point, the size of these bundles becomes unsuitable for practical use in typical compounding and feeding equipment. Adding water beyond this point results in a slurry that is not sufficiently bound into flocculated particles. Generally, the liquid (typically water) content in the processing mixture is often in the range of approximately 10% to 50% by weight relative to the total weight of the mixture (sum of fiber + binder material + liquid + other small amounts of components). Rotating vessels may or may not have internal baffles, or they may have internal baffles that promote a stronger tumbling action, especially when the tangential velocity is slow during rotational tumbling within the rotating vessel. Generally, the tangential velocity of the inner wall of a rotating container during rotational tumbling is often in the range of 0.3 m / s to 1.4 m / s, and in many operations tested with rotating drums without internal baffles, a tangential velocity in the range of 0.6 m / s to 0.8 m / s works well. If the rotational speed is too high, the fibers adhere to the drum wall and little or no tumbling action for bundling occurs. If the rotational speed is too low, the rate of bundling is slow or almost negligible. By adding internal baffles, satisfactory results can be obtained while operating at even lower speeds compared to using the same rotating container without internal baffles. When internal baffles are used, the rotating container has at least one, preferably at least three, internal baffles, which project inward from the rotating wall of the container toward the interior of the container. In some preferred embodiments, the internal baffles are arranged at equal intervals radially around the rotation axis of the container. The internal baffle may extend from the container wall toward the interior of the container to a distance of up to 50% of the container radius, preferably extending at least 50 millimeters from the container wall. The internal baffle may extend toward the interior of the container perpendicular to the tangent to the container wall and may also be aligned longitudinally with the axis of rotation.Alternatively, one or more internal baffles may be positioned at an angle other than a right angle to the tangent to the wall and / or aligned longitudinally but not aligned with the axis of rotation (for example, spirally arranged along the container wall). Figure 4 illustrates a rotatable processing vessel 180 shown in the form of a rotating cylindrical drum, comprising a container wall 182 and four baffles 184 arranged radially at equal intervals around the axis of rotation 186 and projecting inward from the container wall 182 toward the axis of rotation 186. For illustrative purposes, Figure 4 shows directional arrows indicating that the processing vessel 180 rotates clockwise around the axis of rotation 186, but the rotation may also be counterclockwise.

[0037] Generally, bulk products containing fiber-containing particles tend to exhibit better fluidity as the untapped bulk density increases, as the filled bulk density increases, and as the angle of repose decreases. When a particular fiber supply has a weight-average fiber length within the range for the treatment described herein, appropriate treatment conditions for preparing aggregates for fiber-containing particles have been selected and optimized without excessive experimentation through standard treatment tests in which the above-mentioned treatment variables have been prepared, and have appropriate size and shape. Furthermore, fiber-containing particles can be obtained that are suitable for handling in bulk products and exhibit properties suitable for fiber degradation and dispersion during polymer compounding.

[0038] As shown in Figure 3, the exemplary method may include optional preliminary processing 210 to prepare the fiber feed 202 and / or binder material 204 into a form suitable for tumbling 206 (preferably rotational tumbling). Alternatively, it may include optional subsequent processing 212 to prepare a final fiber-containing particle product 214 from the process 200. As understood, if the exemplary method in Figure 3 does not include the subsequent processing 212, aggregates 208 may constitute the fiber-containing particles 214 of the process in Figure 3. The fiber-containing particles 214 may be recovered as a bulk product or incorporated into a bulk product.

[0039] In the example of the pretreatment 210 shown in Figure 5, a preliminary fiber feed 228 is subjected to treatment, which comprises the following five optional operations: first length reduction of the reinforcing fibers 222 (e.g., first cutting), followed by alignment of the reinforcing fibers 224, followed by second length reduction of the reinforcing fibers 225 (e.g., second cutting), followed by fiber size classification of the reinforcing fibers 227, and premixing 226 of the reinforcing fibers with a binder material feed 236 to prepare a premixture 238 for treatment in tumbling 206 (Figure 3). If the method of the present disclosure comprises treatment of the first aspect of the present disclosure, the pretreatment 210 comprises fiber size classification 227, and the first length reduction 222, alignment 224, second length reduction 225, and premixing 226 are preferably but optionally included in the pretreatment 210. If the method of the present disclosure comprises processing of the second aspect of the present disclosure, the pre-processing 210 comprises alignment 224, and a first length reduction 222, a second length reduction 225, fiber size classification 227, and pre-mixing 226 are preferably but optionally included in the pre-processing 210. If the method of the present disclosure comprises processing of the third aspect of the present disclosure, the pre-processing 210 comprises a first length reduction 222 or a second length reduction 225, preferably both, and other processing operations illustrated in Figure 5 are preferably but optionally included in the pre-processing 210.

[0040] In any first length reduction 222, reinforcing fibers from the reserve fiber supply 228 are cut or subjected to other fiber length reduction processes, thereby preparing treated reinforcing fibers 230 with a shorter weight-average fiber length than the reinforcing fibers supplied to the first length reduction 222.

[0041] In any alignment 224, the longitudinal alignment of the reinforcing fibers being processed increases from a more random longitudinal alignment in the feed to the alignment 224 to a more longitudinally aligned orientation as an aligned fiber feed of processed reinforcing fibers 229. In addition to increasing the longitudinal alignment of the fibers themselves, the longitudinal alignment of the reinforcing fibers is further increased in the alignment 224 with respect to the movement or mechanical conveying direction of the reinforcing fibers in the alignment 224 (mechanical direction of conveying), so the mechanical conveying and longitudinal alignment of the reinforcing fibers in the second length reduction 225 and in the process thereto are further increased. The longitudinal alignment of the fibers with respect to each other and the mechanical conveying direction may be achieved using any available fiber alignment technique. One example of an alignment process is to bring the reinforcing fibers into contact with an alignment channel or alignment slot extending along the mechanical conveying direction. As the reinforcing fibers come into contact with the alignment channel and / or alignment slot and settle into the alignment channel and / or alignment slot, the degree of longitudinal alignment of the reinforcing fibers increases. Such alignment channels and / or alignment slots may be, for example, part of a vibrating conveyor. Hereinafter, we refer to Figures 16 and 17, which illustrate an example of increasing fiber alignment using alignment channels and / or alignment slots provided in a vibrating conveyor.

[0042] Figure 16 shows a portion of the conveying deck 201 of a vibrating conveyor for transporting reinforcing fibers in the machine transport direction (machine direction of transport) 203. The conveying deck 201 has a plurality of alignment channels 205 that extend longitudinally along the machine transport direction 203. As the reinforcing fibers are vibrated and move along the conveying deck 201 in the machine transport direction 203, the reinforcing fibers come into contact with the channel walls 207 that extend longitudinally in the alignment channels 205 and tend to be biased to align longitudinally. Most of the reinforcing fibers that fit into the alignment channels 205 during transport along the conveying deck 201 are aligned longitudinally along the machine transport direction 203. During operation, the conveying deck 201 is vibrated, and the vibration of the conveying deck 201 may be applied laterally and / or vertically, and both lateral and vertical vibrations are preferred. The conveying deck 201 may be inclined downward in the machine transport direction 203 to assist in the transport of reinforcing fibers in the machine transport direction 203. After being aligned within the alignment channels, the aligned reinforcing fibers may continue to be transported toward downstream processing, such as a second length reduction 225. Such transport toward subsequent processing may be carried out along the end of the transport deck 201 that does not include the alignment channels 205, or by transferring the aligned reinforcing fibers to a subsequent transport unit. Since some reinforcing fibers may not fit into the alignment channels 205, such reinforcing fibers that do not fit into the alignment channels 205 may be separated from the reinforcing fibers that do fit into the alignment channels 205, or they may be transported together and further processed. Even if not all of the reinforcing fibers to be processed fit into the alignment channels 205, the overall degree of alignment of the reinforcing fibers to be processed is greatly improved.

[0043] Figure 17 shows a portion of the conveying deck 211 of a vibrating conveyor for transporting reinforcing fibers in the machine transport direction (machine direction) 213 during processing. The conveying deck 211 has a plurality of alignment slots 215 that extend longitudinally along the machine transport direction 213. As the reinforcing fibers are vibrated and move along the conveying deck 211 in the machine transport direction 213, the reinforcing fibers come into contact with the alignment slots 215 and tend to be deflected to align along the alignment slots 215. Reinforcing fibers that are sufficiently aligned in the alignment slots 215 settle into the alignment slots 215, pass through the alignment slots 215, are collected on the lower deck 217 of the vibrating conveyor, and are transported along the lower deck 217. The reinforcing fibers passing through the alignment slots 215 have a significantly higher degree of alignment with respect to each other and with respect to the machine transport direction 213. The aligned fibers on the lower deck 217 may then be transported further to be used for further downstream processing, such as processing in a second length reduction 225. During operation, the conveying deck 211 and the lower deck 217 are subjected to lateral and / or vertical vibrations, preferably both, and are vibrated simultaneously or independently. Furthermore, the conveying deck 211 and the lower deck 217 may be inclined downward in the mechanical conveying direction 213 to assist in the conveying of the reinforcing fibers in the mechanical conveying direction 213. Aligned reinforcing fibers on the lower deck 217 may be conveyed along the lower deck 217 for subsequent processing, or transferred to another conveying unit for further conveying. Some reinforcing fibers during processing may not pass through the alignment slots 215, and such fibers may be removed and used for alternative processing, or recombined with another layer of aligned reinforcing fibers on the lower deck 217. Even if not all reinforcing fibers during processing pass through the alignment slots 215 and are recombined with fibers that have passed through the alignment slots 215, the overall alignment of the reinforcing fibers being processed is greatly improved.

[0044] The alignment channel and alignment slot features in Figures 16 and 17 may be combined to promote the development of even higher alignment of reinforcing fibers. For example, fiber alignment can be further improved by providing a narrower alignment slot extending longitudinally at the bottom of the alignment channel 205 in Figure 16, through which the reinforcing fibers pass. Similarly, the lower deck 217 in Figure 17 may be composed of alignment channels extending along the machine transport direction 213.

[0045] For advantageous processing, it is desirable that the alignment channels 205 or alignment slots 215 have a length dimension longer than the majority of the reinforcing fibers being processed in the mechanical conveying direction of the fibers 203, 213, and a width dimension perpendicular to that length dimension is much smaller, preferably a width dimension smaller than the length of the majority of the reinforcing fibers passing through the alignment 224. As shown in Figure 5, optionally, some of the reinforcing fibers 235 that did not successfully align during alignment 224 may be removed and reprocessed via the first length reduction 222, or they may be reprocessed in alignment 224 without length reduction. Since many of these fibers tend to be very long, it may be beneficial to pass them through the first length reduction 222 again before passing them through alignment 224 again.

[0046] Referring to Figure 18, an example is shown in which the reinforcing fibers are aligned more randomly in the longitudinal direction in the feed to the alignment 224, and take on a more aligned form after processing in the alignment 224. Figure 18 shows the supply of the reinforcing fiber feed 218 to the alignment 224 in Figure 5, and how they are transported along the machine transport direction 219 for processing. The high degree of randomness in the alignment of the reinforcing fibers in the reinforcing fiber feed 218 is characteristic of recycled reinforcing fibers recovered from fiber-reinforced composites. The randomness of fiber alignment in such recycled materials presents particular difficulties when processing them into a particle structure suitable for feed for polymer compounds. Figure 18 also shows the aligned fiber feed 220 that may be present in the processed reinforcing fiber 229. As shown in Figure 18, the longitudinal alignment of the reinforcing fibers in the reinforcing fiber feed 218 is highly random, both among the fibers themselves and with respect to the machine transport direction 219. In contrast, the aligned fiber feed 220 comprises reinforcing fibers that are significantly more longitudinally aligned with respect to each other and with respect to the machine conveying direction 219.

[0047] One way to measure the degree of alignment of reinforcing fibers with respect to the machine transport direction is by the alignment angle between the reinforcing fiber and the machine direction. The alignment angle is an acute or right angle (0° to 90°) between the longitudinal alignment of the fiber and a reference direction (e.g., the machine direction). Figure 19 shows, as an example, that a reinforcing fiber 221 is aligned longitudinally with respect to the machine transport direction 223 and has an alignment angle γ between the longitudinal direction of the reinforcing fiber 221 and the machine transport direction 223. Such an alignment angle can vary from 0° (aligned substantially parallel to the reference direction) to 90° (aligned substantially orthogonal to the reference direction). As can be understood, reinforcing fibers are somewhat flexible and may not extend perfectly linearly in the longitudinal direction as shown in Figure 19. However, the alignment angle can be expressed based on a linear fit 223′ for a point along the longitudinal axis of the reinforcing fiber 221. This linear fit 223′ can be expressed, for example, as a linear regression fit of a point along the reinforcing fiber 221. Quantifying the degree to which a group or cluster of reinforcing fibers is aligned with respect to the machine transport direction 223 is possible by acquiring data on the reinforcing fibers in the group using high-resolution visualization techniques, such as a machine vision system, and determining the alignment of the fibers using appropriate data analysis techniques. By using such high-resolution visualization techniques and appropriate data analysis, it is possible to analyze the longitudinal alignment of individual reinforcing fibers and determine the alignment angle with respect to a reference direction (e.g., the machine direction). The alignment angle is determined for the entire group or for a statistically representative portion, and an index of the degree of alignment for that group can be calculated. For example, the average alignment angle for a group of reinforcing fibers can be calculated by averaging the determined alignment angles. This averaging may be performed based on any convenient and useful criterion, and it is possible to determine the average alignment angle using, for example, a number average criterion, a weight average criterion, a length average criterion, or a volume average criterion. Alternatively, or to supplement the determination of the average alignment angle, a useful indicator showing the degree of narrowness or wideness of the distribution of fiber alignment with respect to a reference direction such as the machine transport direction 223 can be obtained by analyzing the proportion of groups that are densely aligned or significantly deviated from the reference direction.In the example of the process illustrated in Figure 5, when the degree of alignment of the reinforcing fibers in the aligned fiber feed of the treated reinforcing fibers 229 is high, the reinforcing fibers are more controlled and uniformly cut during the subsequent processing in the second length reduction 225, resulting in a more uniform fiber length in the fiber feed 202 to tumbling 206 (Figure 3), which contributes to a reduction in the generation of excess fibers and the resulting generation of substandard aggregates (208, Figure 3). For example, one indicator of the longitudinal alignment of reinforcing fibers with respect to the mechanical transport direction 223 can be expressed as a group of reinforcing fibers having an average alignment angle (e.g., number average, weight average, volume average, or length average) that does not exceed a desired maximum average value in the process. As another example, an indicator of the longitudinal alignment of reinforcing fibers with respect to the mechanical transport direction 223 can be expressed as the narrowness of the alignment angle distribution in the group of reinforcing fibers. For example, it is expressed as a maximum permissible fraction (e.g., a few percent, weight percent, volume percent, length percent, etc.), which is the proportion of the portion that has an alignment angle that exceeds the desired maximum alignment angle or is significantly larger than the average alignment angle value of the population.

[0048] As is understood, the weight-average properties (e.g., weight-average length dimension, width dimension, aspect ratio, or alignment angle) of a group or batch of particles (e.g., aggregates or reinforcing fibers) are determined and can be expressed as an average weighted by the particle weights.

[0049]

number

[0050] Here's the question. WA This represents the weight-average characteristic, and Q i and W i Here, is the characteristic value and particle weight of each individual particle belonging to the group or batch, respectively, where n is the number of particles in the group or batch. Similarly, weight percentage refers to the weight ratio based on the total cumulative weight of all particles in the group or particle batch. As is understood, weight-average properties can also be expressed equivalently as mass-average properties.

[0051] As will be understood, the volume average properties (e.g., volume average length dimension, width dimension, aspect ratio, or alignment angle) of a population or batch of particles (e.g., aggregates or reinforcing fibers) are determined as an average weighted by the particle volume (which has porosity within the particle) and are represented by the following equation.

[0052]

Equation

[0053] Here, Q VA represents the volume average property, Q i and V i are, respectively, the property value and the particle volume of each individual particle belonging to the population or batch, and n is the number of particles included in the population or batch. Similarly, the volume percentage refers to the volume ratio based on the total cumulative volume of all the particles included in the population or particle batch.

[0054] As will be understood, the length average properties (e.g., length average alignment angle) of a population or batch of particles (e.g., reinforcing fibers) are determined as an average weighted by the particle length dimension and are represented by the following equation.

[0055]

Equation

[0056] Here, Q LA represents the length average property, Q i and L i are, respectively, the property value and the particle length of each individual particle belonging to the population or batch, and n is the number of particles included in the population or batch. Similarly, the length percentage refers to the length ratio based on the total cumulative length of all the particles included in the population or particle batch.

[0057] As is understood, the number-average properties (e.g., number-average length dimension, width dimension, aspect ratio, or alignment angle) of a group or batch of particles (e.g., aggregates or reinforcing fibers) are the simple arithmetic mean of the particles, determined without weighting, and are expressed by the following equation:

[0058]

number

[0059] Here's the question. NA This represents the number-average characteristic, and Q i is the characteristic value of each individual particle belonging to the group or batch, and n is the number of particles in the group or batch. Similarly, fractions refer to a number ratio based on the total number of particles in the group or particle batch.

[0060] As can be understood, when the cluster of reinforcing fibers in the second length reduction 225 is cut or chopped by a blade positioned transversely to the machine transport direction of the fibers, and operates to give a set cutting length in the machine direction, reinforcing fibers with an alignment angle around 90° may not be cut at all, or if cut, tend to be cut to a length significantly longer than the desired fiber length required for processing into aggregates. This further widens the distribution of cut fiber lengths in the cut fiber product, and such a widened distribution of cut fiber lengths significantly complicates the post-processing (follow-up processing) required to prepare fiber-containing particles with desirable properties for use in polymer compounding. In particular, minimizing the proportion of reinforcing fibers with an alignment angle greater than 45° has been found to result in greater uniformity of cutting and post-processing of cut fibers in preparing suitable aggregates for polymer compounding applications.

[0061] Referring again primarily to Figure 5, even if the pretreatment 210 does not include alignment 224, the reinforcing fiber treatment tends to benefit from having two length reduction treatments (222 and 225), however, it is preferable to include alignment 224, which improves the uniformity of the cut fibers in the treated reinforcing fiber 237 obtained from the second length reduction 225. Similar to the first length reduction 222, the second length reduction 225 may be any length reduction technique or combination thereof for shortening the average fiber length of the reinforcing fiber to be treated, but in a preferred embodiment, each comprises a step of cutting the reinforcing fiber with a cutting blade, which is preferably oriented laterally with respect to the machine transport direction, and transports the reinforcing fiber through each length reduction treatment.

[0062] In the case of reinforcing fiber feeds with a high degree of randomness in fiber alignment, such as typically regenerated reinforcing fibers, it has been found that performing a first length reduction 222 (e.g., first cutting) before alignment 224 results in a better and more reproducible degree of fiber alignment. This is because the reinforcing fibers in the feed to alignment 224 fall into a more uniform length range, and as a result, are better suited to processing through alignment 224.

[0063] As shown in Figure 5, the treated reinforcing fibers 237 from the second length reduction 225 may be further subjected to any fiber size classification 227. During fiber size classification 227, the mixture of discontinuous reinforcing fibers in the treated reinforcing fibers 237 is separated into several different fiber fractions having different weight-average fiber lengths. Such fiber size classification can be achieved by any technique or combination of techniques that separate the reinforcing fibers based on, for example, fiber size (typically fiber length). In typical situations, the reinforcing fibers being treated tend to have the same common composition (e.g., carbon fiber) and the fiber diameter tends to be relatively uniform, so the variation in fiber size will be mainly due to fiber length. Examples of separation techniques used in fiber size classification 227 include air classification, vibratory sorting, sieving, or a combination thereof.

[0064] As illustrated in Figure 5, the treated reinforced fibers 237 supplied to the fiber size classifier 227 are processed to prepare a first fiber fraction 239, which is further processed to prepare a fiber feed 202 (Figure 3), while a second fiber fraction 241 is also obtained. The second fiber fraction 241 mainly consists of excess fibers and therefore has a weight-average fiber length greater than that of the first fiber fraction 239 (which is further processed to prepare the fiber feed 202). As shown in Figure 5, some or all of the second fiber fraction 241 may be recycled upstream of the preprocessing. Such recycling is advantageously returned to a position immediately before the second length reduction 225, alignment 224, or first length reduction 222, and passes through one or more of those preceding processes additionally. Alternatively, some or all of the second fiber fraction 241 may be removed from the preprocessing 210 to be subjected to alternative processing to prepare different products. In a preferred process, the second fiber fraction 241 is recycled upstream of the alignment 224, and more preferably upstream of the first length reduction 222.

[0065] As shown in Figure 5, in the fiber size classification 227, the feed of processed reinforced fibers 237 may be separated into two or more fiber fractions having different weight-average fiber lengths. In the example in Figure 5, an optional preparation of a third fiber fraction (243) is shown, in this example, having a smaller weight-average fiber length than the first fiber fraction 239. As shown in Figure 5, the reinforced fibers contained in the third fiber fraction (243) tend to be too small to be included in the fiber feed 202 and aggregates 208 (Figure 3). The reinforced fibers in the third fiber fraction (243) may be diverted to an alternative treatment, for example, by a milling operation to prepare a pulverized product, which may then be used as a polymer filler.

[0066] In an optional premixing 226, the fiber feed to the premixing 226 (e.g., a first fiber fraction 239) is mixed with a binder feed 236 having some or all of the binder material 204 for tumbling 206 to prepare a premixture 238 having the fibers and binder material. During the premixing 226, the reinforcing fibers are mixed with a liquid (typically water), which may be introduced as the liquid component of the binder feed 236 or separately from the binder feed 236. As understood, the reinforcing fiber feed to the premixing 226 may be treated reinforcing fibers 230 if the pretreatment 210 includes a first length reduction 222 and does not include other exemplary intermediate operations, or may be treated reinforcing fibers 229 if the pretreatment 210 includes alignment 224 and does not include other intermediate operations. Furthermore, if the pretreatment 210 includes a second length reduction 225 but does not include fiber size classification 227, it may be treated reinforced fibers 237, or if the pretreatment 210 includes fiber size classification 227, it may be a first fiber fraction 239. In a particularly preferred embodiment, the pretreatment 210 includes all of the following prior to premixing 226: first length reduction 222, alignment 224, second length reduction 225, and fiber size classification 227. In an even more preferred embodiment, the pretreatment 210 also includes premixing 226. Some or all of the fiber feed 202 and binder material 204 may be supplied to tumbling 206 in the form of a premix 238.

[0067] As can be understood, the reinforcing fibers are typically in a dry form during the process which involves a first length reduction 222, fiber alignment (224), a second length reduction 225, and fiber size classification 227. The premixture 238 comprises reinforcing fibers mixed with a liquid, typically an aqueous liquid, and usually a binder material 204 (Figure 3) as a carrier liquid.

[0068] As can be understood, the order of operations illustrated in Figure 5 is a preferred order, but the order of operations illustrated in Figure 5 may be modified at least to some extent. For example, alignment 224 may be performed before the first length reduction 222. Fiber size classification 227 may also be performed before the first length reduction 222, or between the first length reduction 222 and the second length reduction 225. Furthermore, as with all operations illustrated herein, the operations illustrated in Figure 5 may include additional operations that are inserted into the illustrated order, or placed before or after the illustrated order. For example, the operations illustrated in Figure 5 may include multiple fiber size alignment operations, which may be placed, for example, before the first length reduction 222 and the second length reduction 225. As another example, the operations illustrated in Figure 5 may include multiple fiber size classification operations, which may be placed, for example, between the first length reduction 222 and the second length reduction 225, and after the second length reduction 225.

[0069] Figure 6 is a schematic diagram showing an example of a process that may be performed during any post-processing 212 of Figure 3. Any post-processing 212 illustrated in Figure 6 may include any one or more combinations of particle size classification 254, drying 250, curing 252, and reprocessing 255. In one preferred embodiment, if the binder material is of a type that does not require curing, the post-processing 212 comprises particle size classification 254, drying 250, and reprocessing 255. In another preferred embodiment, if the binder material is of a type that requires curing, the post-processing 212 comprises particle size classification 254, drying 250, curing 252, and reprocessing 255. If the method of the present disclosure comprises a third aspect of the present disclosure, the post-processing 212 illustrated in Figure 6 comprises particle size classification 254 and reprocessing 255.

[0070] As can be understood, the order of operations illustrated in Figure 6 is a preferred order, but the order of operations illustrated in Figure 6 may be modified at least to some extent. For example, particle size classification 254 may be performed after drying 250 or after curing 252, in which case reprocessing 255 would be performed on the aggregates following such drying 250 and / or curing 252. However, it is preferable that particle size classification 254 be performed before the drying or curing operation. This is because the second aggregate fraction 260 and / or the third aggregate fraction 263 are easier to process during reprocessing 255, and the liquid (e.g., water) and binder material contained in the aggregates 208 can be advantageously utilized during reprocessing 255.

[0071] In particle classification (254), fiber-containing particles supplied in the form of aggregates 208 (Figure 3) are subjected to particle size classification 254, and the particle feed is separated into multiple fractions having different weight-average particle sizes. As illustrated in Figure 6, aggregates 208 are processed in particle size classification 254, and a first aggregate fraction 262 and a second aggregate fraction 260 are prepared, with the first aggregate fraction 262 having a weight-average particle length dimension smaller than that of the second aggregate fraction 260. Particle size classification 254 may also include size separation of aggregates 208 into two or more different particle fractions. The process illustrated in Figure 6 optionally also includes the preparation of a third aggregate fraction 263, in this example, which is an intermediate fraction having a weight-average particle length dimension larger than that of the first aggregate fraction 262 and smaller than that of the second aggregate fraction 260. Particle size classification 254 may include separating aggregates by size using one or more size separation techniques, such as screening, vibration classification, air classification, centrifugal classification, optical sorting, and electrostatic classification. A preferred method in size separation within particle size classification is screening. To be understood, when preparing three aggregate fractions as illustrated in any alternative example in Figure 6, the process may include two screens. One having a large opening size and the other a small opening size, so that the first aggregate fraction 262 contains aggregates that pass through the small-sized screen, the second aggregate fraction 260 contains aggregates that are retained by the large-sized screen, and the third aggregate fraction contains aggregates that pass through the large-sized screen and are retained by the small-sized screen. The first aggregate fraction 262 tends to have a narrower distribution of particle length dimensions and, optionally, a narrower distribution of one or more other dimensional characteristics, compared to the aggregates subjected to particle size classification 254. In the process shown in Figure 6, the aggregates of the first aggregate fraction 262 are optionally further processed by drying 250 and / or curing 252 to prepare the bulk product (214) (Figure 3).

[0072] As is understood, aggregates 208 tend to have elongated particle shapes, so setting the sieve dimensions for size classification is not as simple as for granular particles. A particular sieve size may allow a large number of particles with a length dimension greater than the opening size to pass through; therefore, the sieve size used for a particular separation tends to be somewhat smaller than the target particle length dimension that we want to pass through and collect. However, if the sieve size is too small, many of the desired particles may not pass through the sieve and may be excluded. In general, the sieve size must be large enough to accommodate the expected particle width dimension of the aggregates that we want to pass through the sieve, and in practice, the sieve opening size will be somewhat larger than the expected particle width dimension and smaller than the target particle length dimension that we want to pass through for collection. As an example, a sieve size of about 0.25 inches (6.35 millimeters) has been found to be suitable for allowing aggregates with a particle length dimension of about 11-13 millimeters to pass through, while not allowing many aggregates with significantly longer dimensions to pass through. Furthermore, the quality of the pass-through fraction can be improved by subjecting the pass-through fraction to a second sieve through the same sieve opening to further reduce the number of excessively long particles in the collected pass-through fraction. It has also been found that the quality of the collected pass-through fraction can be improved by first subjecting the aggregates recovered from tumbling (e.g., aggregate 208 in Figures 3 and 6) to a first sieve through a large sieve opening to remove very large aggregates, and then subjecting them to a second sieve with an opening size for collecting the desired aggregates. For example, when the goal is to collect aggregates with a particle length of approximately 11-13 millimeters, it has been found that using a first sieve with an opening size of approximately 0.375 inches (9.53 millimeters) and a second sieve with an opening size of approximately 0.25 inches (6.35 millimeters) works well in many situations. Sieving may be assisted by shaking and / or vibrating the sieve.As can be understood, the appropriate sieve size can be determined for any particular aggregate by a simple test on a representative sample of the aggregate batch.

[0073] During any drying 250, the aggregates of the first aggregate fraction 262 are dried, reducing the residual liquid (typically water) content to a desired low level relative to the fiber-containing particles 214. During drying 250, the aggregates are preferably exposed to high temperature and / or reduced pressure to promote the evaporation of the liquid, thereby preparing treated aggregates 256 with a reduced liquid content compared to the aggregates of the first aggregate fraction 262. In situations where the fiber-containing particles 214 are extruded together with the polymer, components that can volatilize at the high temperatures encountered during the extrusion process are often a problem, including residual moisture that can volatilize during the extrusion process. Therefore, in some preferred embodiments, the moisture content in the dried aggregates 256 and fiber-containing particles 214 is very low, usually 0.5% by weight or less, preferably 0.3% by weight or less, and even more preferably 0.2% by weight or less. However, small amounts of residual moisture may be present, for example, at least 0.001% by weight, or at least 0.01% by weight.

[0074] Optional curing 252 may be included if curing is required for the binder material to fully cure to form the final binder composition. Curing may be initiated by an appropriate energy source depending on the properties of the binder material 204, the energy source being, for example, radiation (light) or heat, and in many curing embodiments, thermocuring is more preferred. Curing 252 may be included, for example, if the binder material 204 comprises a thermosetting resin (e.g., epoxy resin) that crosslinks during curing. In some embodiments, the binder material may comprise a thermoplastic polymer while not containing a thermosetting resin. Binder systems using thermoplastic polymers can often be processed without requiring curing 252. However, some binder systems using thermoplastic polymers may benefit from a process involving very high-temperature curing 252, for example, to remove chemical functional groups added to the thermoplastic polymer to improve its solubility in aqueous solutions or to improve its wettability to fibers. If the post-treatment 212 in Figure 6 includes drying 250, the feed for curing 252 may be dried aggregates 256, or otherwise aggregates of the first aggregate fraction 262, or aggregates 208 if the treatment does not include either particle size classification 254 or drying 250. If the post-treatment 212 includes both drying 250 and curing 252, drying 250 and curing 252 may be performed as separate operations or as separate steps of a combined operation. For example, drying 250 may be performed first at a lower temperature (lower elevated temperament), followed by curing 252 at a higher temperature in the same processing apparatus (e.g., the same oven).

[0075] As shown in Figure 6, some or all of the second aggregate fraction 260 and / or the third aggregate fraction 263 are subjected to reprocessing 255. Also as shown in Figure 6, some or all of the second aggregate fraction 260 and / or the third aggregate fraction 263 may be diverted to an alternative treatment other than reprocessing 255. However, if the post-processing 212 includes reprocessing 255, at least some of the second aggregate fraction 260, and optionally some of the third aggregate fraction 263, are supplied to reprocessing 255. Typically, at least some, preferably substantially all, of the second aggregate fraction 260 are subjected to reprocessing 255.

[0076] Figure 20 shows an example of a process carried out during reprocessing 255, with at least a portion of the second aggregate fraction 260, and optionally the third aggregate fraction 263, as the feed. In the example of reprocessing 255 in Figure 20, the aggregates are subjected to a length reduction process 242 (e.g., by cutting), thereby shortening (reducing) the length of at least a portion of the discontinuous reinforcing fibers in the second aggregate fraction 260. This prepares reprocessed reinforcing fibers 243 that have a smaller weight-average length dimension than the reinforcing fibers in the second aggregate fraction 260. In addition to shortening the length of the reinforcing fibers, the length reduction process 242 also plays a role in favorably separating the reinforcing fibers from the particle structure of the feed aggregates. As can be understood, the reprocessed reinforcing fibers 243 exist in a state mixed with the binder material and liquid that was present in the aggregates subjected to the length reduction process 242. Subsequently, the reprocessed reinforced fibers 243, along with the associated binder material and liquid, are subjected to a manufacturing process (production process) 244 to prepare fiber-containing particles 245 for inclusion in bulk products.

[0077] During the length reduction treatment 242, the reinforcing fibers of the second aggregate fraction 260, and optionally the reinforcing fibers of the third aggregate fraction 263, are subjected to appropriate fiber length reduction techniques, such as cutting with a blade. The length reduction treatment 242 may include the same or similar fiber length reduction techniques and treatments as those described, for example, in relation to the first length reduction 222 and / or second length reduction 225 in Figure 5. One possibility is to introduce the reprocessed reinforcing fibers 243 into the pretreatment 210 in Figure 5, for example, upstream of the first length reduction 222, or between the first length reduction 222 and the second length reduction 225. In this case, the length reduction treatment 242 in Figure 20 may be provided by the first length reduction 222 and / or second length reduction 225 in the pretreatment 210 in Figure 5. However, preferably the length reduction treatment 242 is carried out separately from the pretreatment 210. This is because the presence of liquid and binder material associated with the reprocessed reinforced fibers 243 significantly complicates the drying fiber treatment in the first length reduction 222 and second length reduction 225 in Figure 5.

[0078] If the length reduction treatment 242 in Figure 20 is performed separately from the preliminary treatment 210 in Figure 5, the aggregates of the second aggregate fraction 260 and / or the third aggregate fraction 263 may be favorably treated in their "as-is" state, including the liquid and binder material. In a preferred treatment, the aggregates of the second aggregate fraction 260 (optionally the third aggregate fraction 263) have the same or similar concentrations of liquid (e.g., water) and binder material as those in the aggregates 208 recovered from tumbling 206, from which the first aggregate fraction 260 (optionally the third aggregate fraction 263) is prepared. The reprocessed reinforced fibers 243 will exist in a mixed state with the liquid and binder material derived from the first aggregate fraction 260 (optionally the third aggregate fraction 263). Preferably, the mixture comprising the reprocessed reinforced fibers 243 also has the same or similar concentrations of liquid and binder material in the aggregates of the second aggregate fraction 260 (optionally, the third aggregate fraction 263). This liquid may be added as needed, for example, to replenish the liquid lost by evaporation during the process between the initial recovery of the aggregates 208 from tumbling 206 and the recovery of the reprocessed reinforced fibers 243 from the length reduction process 242, or as required for the tumbling performed during the manufacturing process 244. In other words, the liquid can be managed and replenished between the initial recovery of the aggregates 208 from tumbling 206 and the recovery of the reprocessed reinforced fibers 243 from the length reduction process 242.

[0079] In the manufacturing process 244 of Figure 20, the reprocessed reinforced fibers 243 are subjected to specific processing operations for preparing fiber-containing particles 245. A reference to Figure 21 is made here, along with an example of the processes performed in the manufacturing process 244 of Figure 20. The example of the manufacturing process 244 in Figure 21 comprises the preparation of aggregates (246), followed by particle size classification 247, and then the preparation of fiber-containing particles (248), resulting in the production (manufacturing) of fiber-containing particles 245.

[0080] Referring further to Figure 21, during the preparation of the aggregate (246), a treatment mixture comprising reprocessed reinforced fibers 243, a binder material, and typically a liquid (e.g., water) is subjected to tumbling to form reprocessed aggregates 249. These reprocessed aggregates 249 comprise at least a portion of the reprocessed reinforced fibers 243 and the associated binder material and liquid contained in the treatment mixture. Such reprocessed aggregates 249 may have the same or similar particle structure as described elsewhere herein, or similar to those illustrated or described in relation to Figures 1 to 3, for example, and the tumbling may be carried out in the same or the same manner as described in the operation of tumbling 206 in Figure 3. As previously stated, the treatment mixture for tumbling carried out during the preparation of the reprocessed aggregates 246 also typically comprises a liquid (e.g., water), and the treatment mixture may have the components and properties described with respect to tumbling 206 (Figure 3) or elsewhere in this specification. For example, the treatment mixture for tumbling performed during the preparation of the reprocessed aggregates 246 may include reinforcing fibers, binder material, and water at concentrations described elsewhere in this specification. In a preferred embodiment of the preparation of the reprocessed aggregates 246, the treatment mixture subjected to tumbling comprises the binder material and liquid (e.g., water) of the second aggregate fraction 260 and / or third aggregate fraction 263 recovered from the particle size classification 254, preferably in the same or similar concentrations as with the aggregates 208. Advantageously, the binder material and liquid from the initial tumbling treatment (e.g., tumbling 206 in Figure 3) are still associated with the reprocessed reinforcing fibers 243 following the preparation of the reprocessed aggregates 246, and are advantageously reprocessed together with the reprocessed reinforcing fibers 243, thereby enabling the preparation of reprocessed aggregates 249 during the manufacturing treatment 244.

[0081] As shown in Figure 21, the reprocessed aggregates 249 are subjected to a classification process (247) to prepare multiple fractions of the reprocessed aggregates 249. These fractions include at least a first aggregate fraction 262' and a second aggregate fraction 260'. The second aggregate fraction 260' has a larger weight-average particle length dimension than the first aggregate fraction 262'. In the classification process (247), more than two aggregate fractions may be prepared, and Figure 21 shows the preparation of a third aggregate fraction 263' as an arbitrary example. This third aggregate fraction 263' may have a weight-average particle length dimension between the first aggregate fraction 262' and the second aggregate fraction 260'. The first aggregate fraction 262', the second aggregate fraction 260', and the third aggregate fraction 263' may have the same or similar particle structure and properties as the first aggregate fraction 262, the second aggregate fraction 260, and the third aggregate fraction 263 obtained in the classification process (254) shown in Figure 6, or as described elsewhere in this specification. The classification process (247) may be carried out in the same or similar manner as the classification process (254) shown in Figure 6, and using the same or similar apparatus.

[0082] As shown in Figure 21, the second aggregate fraction 262' is subjected to a fiber-containing particle preparation process 248 for producing fiber-containing particles 245. If the aggregates of the second aggregate fraction 262' have a particle structure and properties desirable for incorporation into a bulk product, the fiber-containing particle preparation process 248 may simply include collecting some or all of the aggregates of the second aggregate fraction 262' and recovering them as a batch of fiber-containing particles 245 for incorporation into a bulk product. In other embodiments, the aggregates of the second aggregate fraction 262' may be processed in the fiber-containing particle preparation process 248 and modified to alter one or more properties of the aggregates to prepare modified forms of fiber-containing particles 245. Such processing in the fiber-containing particle preparation process 248 may include drying and / or curing processes, which are similar to or identical to, for example, the drying process (250) and / or curing process (252) in Figure 6. In yet another embodiment, part or all of the manufacturing process 244 in Figure 21 may be carried out by introducing the reprocessed reinforced fibers together with the associated binder material and liquid into an appropriate stage of the process in Figure 3. For example, they may be introduced into the premixing process (226) in Figure 5, and the premix (236) may comprise the regenerated reinforced fibers of the reprocessed reinforced fibers 243, along with the associated binder material and liquid.

[0083] In some embodiments, the length reduction process 242 and manufacturing process 244 of the reprocessing 255 (Figure 20) may be carried out by recycling aggregates of the second aggregate fraction 260, and optionally aggregates of the third aggregate fraction 263, into the preprocessing 210 of Figure 3, with appropriate modifications taken to take into account the binder material and liquid present in the recycled aggregates. An example of such an embodiment is shown in Figure 22, where aggregates of the second aggregate fraction 260 are recycled from the post-processing 212 (e.g., obtained as a result of the classification process (254) of Figure 6) into the preprocessing 210. For example, the second aggregate fraction 260 (and / or the third aggregate fraction 263, if present) from the classification process (254) of Figure 6 may be recycled immediately before the first cutting process (222) or immediately before the second cutting process (225) of the preprocessing 210 of Figure 5. In this case, the length reduction process 242 in Figure 20 is provided by the first cutting process (222) and / or the second cutting process (225) in Figure 5; the aggregate preparation process (246) in the manufacturing process 244 in Figures 20 and 21 is provided by reprocessing by the rotary tumbling process (206) in Figure 3; the classification process (247) in the manufacturing process in Figures 20 and 21 is provided by the classification process (254) in Figure 6; and furthermore, the fiber-containing particle preparation process 248 in the manufacturing process in Figures 20 and 21 may be provided by the drying process (250) and / or the curing process (252) in Figure 6. However, as in the above description, the presence of liquid and binder material in the second aggregate fraction 260 complicates the recycling of the second aggregate fraction 260 to the first cutting process (222) and / or the second cutting process (225) with a fresh supply of dried reinforcing fibers. Therefore, it is particularly preferable not to recycle the second aggregate fraction 260 (or the third aggregate fraction 263) into the preliminary treatment 210 shown in Figure 3.

[0084] In a more preferred embodiment, the aggregates of the second aggregate fraction 260, and optionally the aggregates of the third aggregate fraction 263, are processed separately from the processes in Figures 3, 5, and 6. However, such separate processes may include operations similar to those performed in the processes in Figures 3, 5, and 6 (e.g., cutting of reinforcing fibers, rotary tumbling, particle size classification of aggregates, and drying).

[0085] Furthermore, a certain amount of reinforcing fibers may be subjected to multiple reprocessing steps in oversized aggregates separated by particle size classification after the preparation of the aggregates, and bulk products with similar properties may be prepared after each reprocessing step. However, it has been found that the properties of the bulk product deteriorate when the reinforcing fibers are subjected to an excessive number of reprocessing steps involving fiber cutting. In general, when reinforcing fibers in oversized aggregates are subjected to fiber cutting in more than three consecutive reprocessing steps, the properties of the resulting bulk product tend to deteriorate. The fiber-containing particles prepared by the initial treatment and each reprocessing of the oversized aggregates may be blended into a single combined bulk product, or they may be maintained as separate bulk product batches to improve quality control and product tracking.

[0086] Referring to Figure 23, this shows an example of a process in which the oversized aggregate fraction is reprocessed separately, and the reinforcing fibers are reprocessed up to four times. In the process shown in Figure 23, if the number is not accompanied by an apostrophe, it indicates elements related to the initial processing of the initial supply of regenerated reinforcing fibers (e.g., the processes in Figures 3, 5, and 6). If the number is accompanied by one apostrophe (′), it indicates elements related to the first stage of reprocessing of the reinforcing fibers, and if the number is accompanied by two apostrophes (′′), it indicates elements related to the second stage of reprocessing. If the number is accompanied by three apostrophes (′′′), it indicates elements related to the third stage of reprocessing, and if the number is accompanied by four apostrophes (′′′′), it indicates elements related to the fourth stage of reprocessing.

[0087] In the process shown in Figure 23, an aggregate 506 is prepared by subjecting a reinforcing fiber feed 502, which is a reinforcing fiber feed, to process 504. The reinforcing fiber feed 502 may contain recycled reinforcing fibers (e.g., carbon fibers) recovered from a fiber-reinforced composite material, or it is typically composed of discontinuous dry reinforcing fibers. Process 504 comprises at least a cutting process to shorten the weight-average fiber length of the reinforcing fiber feed 502, and a rotary tumbling process comprising the length-reduced reinforcing fibers and binder material, thereby forming the aggregate 506. The rotary tumbling in process 504 may be the same as that described for the rotary tumbling process (206) in the process shown in Figure 3, or preferably rotary tumbling using a rotary vessel. The aggregate 506 obtained in process 504 in Figure 23 may have the characteristics described for the aggregate 208 prepared in the process shown in Figure 3. The pre-rotation tumbling treatment in process 504 may include one or more operations described with respect to the pre-treatment 210 in Figure 3 or Figure 5. For example, the cutting of reinforcing fibers in process 504 may include either or both of the first cutting treatment (222) and / or the second cutting treatment (225) in the pre-treatment 210 in Figure 5. The pre-rotation tumbling treatment in process 504 may also include one or more, preferably comprising at least an alignment treatment (224), more preferably at least an alignment treatment (224) and a pre-mixing treatment (226), and more preferably all of the alignment treatment (224), fiber classification treatment (227), and pre-mixing treatment (226).

[0088] After preparation, the aggregates 506 are subjected to sorting 508 to remove non-conforming aggregates (506). Sorting 508 may include, for example, a visual inspection for conformity, and remove aggregates 506 that are visually inadequate in terms of size or structure (e.g., "frayed" aggregates). The accepted fraction (A) of the aggregates obtained from sorting 508 proceeds to initial processing, and the rejected fraction (B) is sent for reprocessing.

[0089] The receiving fraction (A) obtained from the separation process 508 is subjected to a classification process 510, which separates the aggregates into three fractions. The first aggregate fraction 1 has the smallest weight-average particle length, and the second aggregate fraction 2 has the largest weight-average particle length. The third aggregate fraction 3 has a weight-average particle length between the first aggregate fraction 1 and the second aggregate fraction 2. In Figure 23, this naming convention is consistently maintained, with the fraction identified as "1" having a smaller weight-average particle length than the fraction identified as "2". The fraction identified as "3" has a weight-average particle length intermediate between "1" and "2". The classification process 510 and other classification processes in the reprocessing stage of Figure 23 may include any technique or combination of techniques for separating particles by size, or may use one or more techniques described elsewhere in this specification, for example. Classification process 510 or other classification processes in the reprocessing stage of Figure 23 may have the same or similar characteristics as those described for classification process (254) in post-processing 212 of Figure 6.

[0090] The first aggregate fraction 1 obtained from the classification process 510 is subjected to a drying process 512, and the dried aggregates are recovered as a bulk product 514. The second aggregate fraction 2 and the third aggregate fraction 3 obtained from the classification process 510, as well as the rejected fraction B from the separation process 508, are each subjected separately to the first stage of reprocessing, thereby being subjected to a process comprising process 504' and classification process 510'.

[0091] In the first stage of reprocessing, process 504' is subjected to a cutting process to reduce the weight-average fiber length of the reinforcing fibers in the aggregates. The cutting process may include the same or similar processes as, for example, the first cutting process (222) and / or the second cutting process (225) in the preliminary process 210 in Figure 5. After the cutting process, process 504' includes a step of preparing the first-stage reprocessed aggregates 506' by rotary tumbling the processed mixture comprising the reinforcing fibers and binder material. The rotary tumbling in process 504' may be the same or similar as the rotary tumbling in process 504, or may be similar to the rotary tumbling process (206) described in Figure 3, and is preferably rotary tumbling using a rotary vessel.

[0092] As understood, the aggregates subjected to process 504' include reinforcing fibers, a liquid, and a binder material, and preferably the cutting process is carried out in the same state as prepared in process 504 with the liquid and binder material, without substantial drying and without substantially altering the particle structure of the aggregates before the cutting process. More preferably, the aggregates subjected to reprocessing are maintained in an environment that substantially prevents evaporation of the liquid before the cutting process in process 504', and the liquid and binder material are retained together with the cut reinforcing fibers and are included in the processing mixture subjected to rotary tumbling in process 504'. However, if a considerable amount of liquid is lost by evaporation in the steps prior to rotary tumbling in process 504', additional liquid may be added to compensate for the loss, thereby preparing a processing mixture having the desired liquid concentration suitable for rotary tumbling.

[0093] The pre-tumbling treatment in process 504' may include, in addition to the cutting treatment, other treatments leading to the preparation of the treatment mixture to be tumbling. For example, process 504' may include an alignment treatment to better align the aggregates longitudinally in the direction of mechanical transport, thereby improving the uniformity of the cutting treatment of the reinforcing fibers in the aggregates to be treated. Such an alignment treatment of the aggregates may be carried out using any alignment technique described, for example, with respect to the fiber alignment treatment (224) in Figure 5, adapted for the treatment of aggregate particles instead of dry discontinuous reinforcing fibers. As another example, process 504' may include pre-mixing the components for the treatment mixture to be tumbling, for example, by adding a liquid before tumbling as needed.

[0094] In the first reprocessing stage, the first-stage reprocessed aggregates 506′ are subjected to classification 510′ to prepare two size-separated aggregate fractions (1′ and 2′) or three size-separated aggregate fractions (1′, 2′, and 3′). In either case, the first aggregate fraction 1′ having the smallest weight-average particle length is subjected to drying 512′, and the dried aggregates are recovered as a bulk product 514′. Each aggregate fraction with a larger weight-average particle length (fractions 2′ and 3′) is subjected to second-stage reprocessing. Some or all of these weight-average particle length aggregate fractions may be subjected to second-stage reprocessing in combination or separately. In the processing example shown in Figure 23, aggregate fraction 2' is subjected to the second reprocessing stage by binding treatment 516'', while aggregate fraction 3' is subjected to the second reprocessing stage separately.

[0095] The reprocessing in the second stage is the same as that described for the first stage of reprocessing. In the second stage of reprocessing, the non-compliant aggregates to be processed are subjected to process 504'' to prepare the second-stage reprocessed aggregates 506''. Subsequently, the second-stage reprocessed aggregates 506'' are subjected to a classification process 510'' to prepare separated aggregate fractions (1'' and 2''). The first aggregate fraction 1'', which has a small weight-average particle length, is subjected to a drying process 512'', and the dried aggregates are recovered as a bulk product 514''. Process 504'' comprises at least a cutting process to reduce the weight-average fiber length of the reinforcing fibers in the aggregates subjected to the second stage of reprocessing, and a rotary tumbling process to prepare the second-stage reprocessed aggregates 506'', and may further include other operations described for process 504'' in the first stage of reprocessing.

[0096] The non-conforming aggregates (fraction 2'') obtained from the second reprocessing stage are sent to the third reprocessing stage. In the example in Figure 23, the non-conforming aggregates (fraction 2'') are subjected to the third reprocessing stage by a binding treatment 516''''. In the third reprocessing stage, the bound non-conforming aggregates 518'''' are subjected to treatment 504'''' to prepare the third-stage reprocessed aggregates 506'''', which are then subjected to a classification treatment 510'''' to prepare two size-separated aggregate fractions (1'''' and 2''''). The first aggregate fraction 1'''', which has a smaller weight-average particle length, is subjected to a drying treatment 512'''', and the dried aggregates are recovered as a bulk product 514''''.

[0097] The non-compliant aggregate fraction (2′′′) obtained from the third reprocessing stage is sent to the fourth reprocessing stage. In the fourth reprocessing stage, the non-compliant aggregates are subjected to treatment 504′′′′ to prepare the fourth-stage reprocessed aggregates 506′′′′, which are then subjected to classification treatment 510′′′′ to prepare size-separated aggregate fractions (1′′′′ and 2′′′′). The first aggregate fraction 1′′′′, which has a small weight-average particle length, is subjected to drying treatment 512′′′′, and the dried aggregates are recovered as bulk product 514′′′′. The non-compliant aggregate fraction 2′′′′ constitutes the final rejection fraction 524′′′′, which is either discarded or subjected to an alternative treatment, such as grinding treatment, to prepare a grinding product.

[0098] The processes 504′′′ and 504′′′′ in the third and fourth reprocessing stages may be the same or different, but both include a cutting process to reduce the weight-average fiber length of the reinforcing fibers in the aggregate to be processed, and a process to prepare the aggregate by rotary tumbling the cut reinforcing fibers. Preferably, the processes 504′′′ and 504′′′′ in the third and fourth reprocessing stages are the same or similar to the process 504′′ in the second reprocessing stage. Similarly, the classification processes 510′′′ and 510′′′′ in the third and fourth reprocessing stages may include the same size classification process or different size classification processes, preferably the same or similar, and more preferably the same or similar to the classification process 510′′ in the second reprocessing stage.

[0099] Referring to Figure 7, this is a schematic process diagram showing an example of a process for manufacturing a fiber-containing product. The process in Figure 7 comprises process 200 in Figure 3. In this process 200, a preliminary fiber feed 270, which is a preliminary feed of fibers, is processed to prepare a fiber-containing bulk product 272. The preliminary fiber feed 270 may be provided in the form of fiber feed 202 in Figure 3, for example, if process 200 does not include a preliminary process 210, or in the form of preliminary fiber feed 228, if process 200 includes a preliminary process 210. The fiber-containing bulk product 272 may be in the form of a batch of fiber-containing particles 214 in process 200 in Figure 3. The fiber-containing bulk product 272 may be a blended product obtained by mixing fiber-containing particles 214 with one or more other particulate components. For example, it may be mixed with other fiber-containing particles that have additional fibers, and these additional fibers may have the same composition as the fibers of the fiber-containing particles 214 or a different composition (other than carbon fibers). For example, the fiber-containing bulk product 272 may include a blend of carbon fibers in the fiber-containing particles and other particles having additional carbon fibers or additional fibers of a different composition (other than carbon fibers). As shown in Figure 7, this method may optionally include processes performed before and / or after process 200. The process in Figure 7 may optionally include a recycling process 300 to prepare a preliminary fiber feed 270 by processing the composite feed 302, or optionally include a composite preparation process 400 to prepare a fiber-reinforced composite product 402.

[0100] Figure 8 is a schematic process diagram showing an example of a process that may be carried out in an arbitrary composite preparation process 400 to prepare a fiber-reinforced composite product comprising reinforcing fibers obtained from a fiber-containing bulk product 272. In the example in Figure 8, the composite preparation process 400 includes a process 404 in which the fibers of the fiber-containing bulk product 272 are dispersed in a matrix, thereby forming a fiber-reinforced composite 406. The material for the matrix may be supplied as a matrix material feed 408. Additional components 410 are also supplied to the dispersion process 404 and may be included in the fiber-reinforced composite 406. Such additional components 410 may include additives such as functional or non-functional fillers and processing aids. The additional components 410 may also include additional reinforcing fibers in addition to the reinforcing fibers derived from the fiber-containing bulk product 272, and these additional reinforcing fibers may be of the same type as or different from the fibers in the fiber-containing bulk product 272. In some preferred processing embodiments, the dispersion process 404 includes a step of extruding the polymer material of the matrix material supply 408 and adding fiber-containing particles of the fiber-containing bulk product 272 to the polymer material during the extrusion, in which case the fiber-reinforced composite material 406 may be in the form of an extruded molded body.

[0101] Continuing to refer mainly to Figure 8, any composite material preparation process 400 may further include a cooling process 420 for cooling the fiber-reinforced composite material 406. The cooling process 420 may be carried out, for example, by passing the fiber-reinforced composite material 406 through a bath of a cooling liquid (e.g., water). This process is desirable when the composite material prepared in the dispersion process 404 is at a high temperature, for example, in the case of an extrusion process. The cooled composite material 422 obtained by the cooling process 420 is subjected to a pelletizing process 426 to prepare pellets 428 of the fiber-reinforced composite material. The pelletizing process 426 may include, for example, cutting extruded strands of a desired diameter into cylindrical pellets of a desired length. After the pelletizing process 426, the pellets 428 are subjected to a blending process 430, in which the pellets 428 are mixed with one or more other particulate components 432 (different from the pellets 428) to form a blended bulk product 434. Any process may also include a molding process 440 in which the fiber-reinforced composite feed is molded, preferably by injection molding, to produce a molded product 442. The fiber-reinforced composite feed to the molding process 440 may be, for example, pellets 428 if the composite preparation process 400 does not include a blending process 430, or a blended bulk product 434 if the composite preparation process 400 includes a blending process 430. As understood, the pellets 428 or the blended bulk product 434 may be sold as bulk products, and the purchaser may use the pellets 428 or the blended bulk product 434 for carrying out the molding process 440 or for other purposes.

[0102] Continuing with the process shown in Figure 7, the preliminary fiber feed 270 may contain virgin fibers or recycled fibers. In a preferred embodiment of the process in Figure 7, the preliminary fiber feed 270 comprises recycled fibers (e.g., recycled carbon fibers). Such recycled fibers may be obtained from any source for supply to the process 200, or optionally prepared by carrying out a recycling process 300 to recover recycled fibers from the composite feed 302. The composite feed 302 to the recycling process 300 may contain scrap and / or waste of fiber-reinforced materials, and recycled reinforced fibers are recovered for use in the preliminary fiber feed 270 for preparing the fiber-containing bulk product 272 by separating the recycled fibers from the matrix of the composite feed 302 in the recycling process 300. The composite feed 302 may contain a matrix of a thermosetting polymer composition or a thermoplastic polymer composition. The thermosetting matrix may contain an uncured thermosetting resin (e.g., a prepreg) or a cured thermosetting polymer composition. The recycling process 300 may include any processing techniques for separating reinforcing fibers from the matrix of the composite feed 302. Examples include thermal decomposition, solvent treatment, or depolymerization of the matrix to release the fibers into a recoverable state. Some preferred embodiments of the recycling process 300 include the processes disclosed in Patent Documents 4, 5, and 6. In some of these preferred embodiments, the composite feed 302 is first subjected to treatment with a first typically liquid solvent, thereby dissolving the matrix material and releasing the fibers into a recoverable state; the first solvent containing the dissolved matrix material is then separated from the released fibers; and the released fibers are further treated with a second solvent, which is usually a gaseous substance such as carbon dioxide, to remove any remaining portion of the first solvent.

[0103] Figure 9 is a schematic process diagram showing an example of a process that may be carried out in any recycling process 300 to prepare a preliminary fiber feed 270 as a preliminary fiber feed having regenerated fibers to be supplied to process 200 by processing a composite feed 302. As shown in Figure 9, the composite feed 302 is subjected to a first process 304, in which the composite feed 302 is brought into contact with a first solvent 306 (preferably a liquid solvent), and most, and possibly substantially all, of the matrix material of the composite feed 302 is dissolved, leaving reinforcing fibers freed from the composite structure. The resulting mixture 308 comprises a filled (contained, loaded) first solvent with dissolved matrix material and freed reinforcing fibers, and is then subjected to liquid-solid separation 310. In this liquid-solid separation 310, most of the packed first solvent, preferably substantially all (excluding the residue), is recovered as a separation liquid 312, and most of the released fibers, preferably substantially all, are recovered as a solid residue 314. The solid residue 314 still contains a residue of the first solvent. The solid residue 314 is subjected to a second treatment 316, in which the solid residue 314 comes into contact with a second solvent 318. This second solvent 318 is the solvent for the first solvent, and not the solvent for the reinforcing fibers. From the second treatment 316, a packed second solvent 320 with the residual portion of the first solvent dissolved in it, and a dry solid residue 322 containing released reinforcing fibers from which the residual portion of the first solvent has been removed are recovered. The dried solid residue 322 may be used directly as the preliminary fiber feed 270 for process 200 as recovered from the second process 316, or it may be further processed as desired to prepare the preliminary fiber feed 270.

[0104] As used herein, the term “bulk product” means a product in particulate form, including, for example, powder, lump, or granules, and having intraparticle voids and interparticle voids. This term may be used synonymously with the term “bulk material.”

[0105] As used herein, the term "bulk density" refers to the apparent density of a given amount of bulk product. Bulk density is determined by dividing the mass of the bulk product by the volume it occupies (including intraparticle voids and interparticle voids).

[0106] As used herein, the terms “uncompacted bulk density” and “free-settling bulk density” are synonymous and refer to the bulk density of a bulk product measured according to the following procedure, which is similar to but modified to ASTM standard D7481-18.

[0107] Weigh a clean, empty 0.5 L straight-walled beaker in grams and record the weight. This beaker may be sourced using, for example, a Cole-Parmer graduated Griffin beaker #SK-34502-46, or an equivalent container.

[0108] Gently sift the bulk product particles from the container into the beaker, filling up to the upper mark. Ensure a neutral filling. A funnel may be used if necessary or convenient.

[0109] • Weigh the filled beaker in grams and determine the weight of the particles in the beaker with an accuracy of at least 0.1 grams by finding the difference between the weight of the filled beaker and the weight of the empty beaker. This difference may be measured directly by tare the scale to the weight of the empty beaker before adding the bulk product, or by measuring the total weight of the beaker and bulk product together and finding the difference between that and the weight of the empty beaker.

[0110] • Bulk density (g / L) is equal to twice the weight of the particles in the filled beaker. As used herein, the term “tapped bulk density” refers to the bulk density of a bulk product measured according to the following procedure, which is similar to, but modified from, ASTM standard D7481-18.

[0111] First, complete the above procedure to determine the density of the uncompacted bulk material. Next, the filled beaker is moved to a hard surface (such as a workbench or counter), and the bottom of the beaker is repeatedly struck against the surface by lifting it 1-2 centimeters above the surface and dropping it. This tapping action is performed at a frequency of approximately 90 times per minute.

[0112] Continue this tapping operation until the sedimentation volume of the bulk product in the beaker becomes substantially constant (variation of approximately 2% or less) over at least 10 taps. • Measure the sedimentation volume of the bulk product in the beaker to the nearest 5 milliliters.

[0113] Tapped bulk density (g / L) is calculated by dividing the weight (in grams) of the bulk product, which has been determined when measuring the uncompacted bulk density, by the measured settling volume (in liters).

[0114] As used herein, "angle of repose" refers to the angle of repose of a stacked pile of bulk products, determined by the following procedure, which is similar to, but modified from, ASTM standard C1444-00.

[0115] Prepare a funnel capable of holding 150 grams of bulk product sample and with an outlet diameter of 2.75 inches (6.9 centimeters). For example, a standard 48-ounce plastic long-neck funnel (model #LX-1614) sold by Home Depot may be used or an equivalent. The specified funnel may be cut to obtain the appropriate outlet diameter as needed.

[0116] Pour 150 grams of bulk product into a funnel, with the outlet covered by a flat object (such as a piece of cardboard). The funnel outlet is held 4.5 inches (11.4 centimeters) above clean paper (e.g., printer paper), and the cover of the funnel outlet is removed to allow the bulk product to flow out of the funnel outlet and form a mound on the paper. The funnel should be held in a stand designed not to obstruct the formation of the mound, and for the bulk product consisting of the fiber-containing particles of this disclosure, a cylindrical corrugated stand with a diameter of 10 inches (25.4 centimeters) is generally suitable.

[0117] • Once the bulk product spill has stopped and the pile has settled, measure and record the two orthogonal diameters at the base of the pile and the height of the pile. Each measurement should be made with an accuracy of 0.25 inches (0.64 centimeters), and calculate the average of the measured diameters.

[0118] The angle of repose is calculated according to the following formula: AR = tan⁻¹(2h / d). Here, AR is the angle of repose, h is the height of the mountain, and d is the average diameter of the base of the mountain.

[0119] <Example> <Example 1> The batches of fiber-containing particles were prepared generally according to the following procedure.

[0120] 1. Recycled carbon fibers recovered from prepreg composites were used as the feedstock and cut using a guillotine-type cutter at cutting settings of 3 mm, 6 mm, or 12 mm. As can be understood, the length of the cut fibers may be longer or shorter than the set value, depending on the length of the original fibers before cutting and the angle at which the fibers were positioned relative to the cutting blade at the time of cutting. To improve the uniformity of the fiber cutting length, the fibers were passed through the chopper three or four times.

[0121] 2. Finally, 10–30 kilograms of cut fibers were placed in a 55-gallon (208.2 liters in US gallons) drum, and water and binder material were added to form a mixture with the cut fibers. This mixture consisted of 20–35% by weight water, 1–5% by weight binder material, and the remainder being cut fibers. An example of the binder material tested is shown in Table 1. The water and binder material were pre-mixed, and the water and binder mixture was poured into the fibers in the 55-gallon drum. Generally, more water by weight was added to cut fibers prepared at a 3 mm cutting setting, and less water by weight was added to cut fibers prepared at a 6 mm or 12 mm cutting setting. After adding the water and binder mixture, the drum was sealed.

[0122] 3. A sealed drum was placed on a drum roller, and the drum containing the contents was rotated for 120 to 210 minutes. The rotation speed of the drum roller was set to 24 revolutions per minute, which corresponds to a tangential velocity of approximately 0.7 meters / second at the inner wall of the drum cylinder. The drum rotation was briefly stopped approximately every 30 minutes to confirm the progress of aggregation and to scrape off any excess fibers adhering to the inner wall of the drum.

[0123] 4. The aggregates obtained by the drum rotation process in Step 3 were removed from the drum and classified using a vibrating screen sorter. Screen opening sizes of 1 / 4 inch (6.35 mm), 3 / 8 inch (9.53 mm), or 1 / 2 inch (12.7 mm) were used to remove oversized particles that did not pass through the screen.

[0124] 5. The classified aggregates were dried in an oven set to 300°F (149°C) for 8-12 hours to remove virtually all moisture. Figure 10 is a photographic image showing an example of recycled carbon fibers before cutting. As shown in Figure 10, recycled carbon fibers exhibit a cotton ball-like structure, and the orientation of the carbon fibers is largely random.

[0125] [Table 1]

[0126] Figure 11 shows photographic images of two preparation batches of fiber-containing particles manufactured from recycled carbon fibers. The fiber-containing particles from each batch are dispersed on a white paper background, making each particle easily visible. One example batch shown at the top of the image was prepared by operating the chopper at a 6 mm setting, and the resulting fiber-containing particles had an average particle length of approximately 12 mm. Another example batch shown at the bottom of the image was prepared by operating the chopper at a 3 mm setting, and the resulting fiber-containing particles had an average particle length of approximately 8 mm. In both batches, the elongated shape of the particles and the general alignment of the fibers along the longitudinal direction of the particles can be seen, and many particles have a well-developed tapered shape at both ends.

[0127] Figure 12 is a photographic image of a bulk product in a beaker, prepared using particles obtained from a batch of fiber-containing particles manufactured using recycled carbon fibers cut to a 6 mm setting as the feedstock. Figure 13 is a photographic image of the bulk product viewed from above. This bulk product was subjected to tests for bulk density and angle of repose according to the method described herein. The bulk product had an untapped bulk density of approximately 200 g / L, a tapped bulk density (tapping density / shaking bulk density) of approximately 300 g / L, and an angle of repose of approximately 36°. These properties indicate that the bulk product has good fluidity and is suitable for feeding into an extruder for compounding with polymers.

[0128] Figure 14 is a photographic image of a single particle obtained from a batch of fiber-containing particles produced using recycled carbon fibers cut at a 6 mm chopper setting as the feedstock. The particle is approximately 12 mm in length and has a well-developed tapered particle shape, with the fibers aligned longitudinally to a high degree relative to the longitudinal direction of the particle. As shown in Figure 14, this example of fiber-containing particle substantially does not contain fibers protruding perpendicular to the longitudinal direction of the particle, thereby promoting good particle flowability in the bulk product.

[0129] Figure 15 is a photographic image showing the inside of a rotating 55-gallon drum containing aggregates formed from recycled carbon fibers cut with a 6-millimeter chopper setting. Transparent caps are fitted to the ends of the drum to allow observation of the contents inside the drum during rotating tumbling.

[0130] <Example 2> To prepare carbon fiber reinforced composites, extrusion tests were performed using batches of fiber-containing particles derived from recycled carbon fibers prepared by the method described in Example 1. Table 2 shows some of the polymers tested for compounding with fiber-containing particles prepared with different chopper settings. Each polymer was extruded using a twin-screw extruder. Some samples were extruded using a Leistritz 27mm twin-screw extruder, while others were extruded using a different extruder. Batches of fiber-containing particles were prepared with chopper settings of 12 mm, 6 mm, or 3 mm. The fiber-containing particles were fed to the extruder from a standard bulk handling system, and various rates of recycled carbon fiber content (filling, loading) in the extruded bodies were set (see Table 2). The Leistritz extruder was fed using a K-Tron T20 vibrating loss infeed feeder. The extruded bodies were passed through a circular die (e.g., a two-hole circular die), and the resulting extruded strands were cut into cylindrical pellets. During extrusion, particles were well fed from the supply hopper to the extruder, and carbon fibers were generally well dispersed from the fiber-containing particles into the polymer melt. Some test pellets were subjected to injection molding, and test specimens of carbon fiber reinforced material were prepared from the pellets. Some extruded pellets made from polyamide polymer were injection molded into ISO 527-2 Type 1A tensile test specimens and ISO 197-2 Type D impact test specimens. The molded material exhibited equivalent tensile strength, modulus of elasticity, and impact strength compared to manufacturer specifications of a 40% carbon fiber reinforced commercial compound using the same base polyamide polymer and virgin carbon fibers. With the use of appropriate high-pressure injection and heated molds, the molding of the test specimens proceeded smoothly. Some molded test specimens were subjected to XCT (computed tomography) analysis, which confirmed that the void distribution and fiber distribution were similar to those of the corresponding reference commercial compound using virgin carbon fibers.

[0131] [Table 2]

[0132] <Examples of combinations of embodiments> Examples of other embodiments (implementations) relating to each aspect of this disclosure, with or without additional features disclosed above or elsewhere in this specification, are summarized in the following numbered paragraphs (clas) and appended claims.

[0133] <Clause 1> A method for manufacturing a bulk product comprising fiber-containing particles in which reinforcing fibers are held within the particle structure by a binder, wherein the method is: A pretreatment step for reinforcing fibers to prepare a discontinuous fiber supply of discontinuous reinforcing fibers, A step of preparing an aggregate comprising at least a portion of the discontinuous reinforcing fibers of the discontinuous fiber supply and a binder material, comprising the steps of mixing the discontinuous fiber supply and the binder material in a processing mixture and rotating and tumbling the processing mixture, It is equipped with, The aforementioned preliminary processing step further, A step of preparing multiple fiber fractions by size classifying a mixture of discontinuous reinforced fibers, wherein each of the multiple fiber fractions comprises at least a first fiber fraction (having a first weight-average fiber length) and a second fiber fraction (having a second weight-average fiber length), and the second weight-average fiber length is greater than the first weight-average fiber length. A step of preparing the discontinuous fiber feed such that it comprises at least a portion of the discontinuous reinforcing fibers of the first fiber fraction, A method that includes [the following features].

[0134] <Clause 2> A method for manufacturing a bulk product comprising fiber-containing particles in which reinforcing fibers are held within the particle structure by a binder, wherein the method is: A pretreatment step for reinforcing fibers to prepare a discontinuous fiber supply of discontinuous reinforcing fibers, A step of preparing an aggregate comprising discontinuous reinforcing fibers of at least a portion of the discontinuous fiber supply and a binder material, comprising the steps of mixing the discontinuous fiber supply and the binder material in a processing mixture and rotating and tumbling the processing mixture, It is equipped with, The aforementioned preliminary processing step further, The process involves preparing an aligned fiber feed by increasing the longitudinal alignment between reinforcing fibers, A step of preparing the discontinuous fiber feed so that it comprises at least a portion of the reinforcing fibers of the aligned fiber feed, A method that includes [the following features].

[0135] <Clause 3> A method for manufacturing a bulk product comprising fiber-containing particles in which reinforcing fibers are held within the particle structure by a binder, wherein the method is: A manufacturing process, wherein the manufacturing process is (i) A step of preparing an aggregate, comprising the step of rotating and tumbling a treatment mixture comprising discontinuous reinforcing fibers and a binder material to form an aggregate comprising at least a portion of the discontinuous reinforcing fibers and at least a portion of the binder material, wherein the aggregate is The particle length dimension is the maximum separation distance between the first longitudinal end and the second longitudinal end in the longitudinal direction of the aggregate, At a longitudinal position between the first longitudinal end and the second longitudinal end, the maximum particle width dimension is the maximum particle width in the direction lateral to the longitudinal direction, The aspect ratio is the ratio obtained by dividing the particle length dimension by the maximum particle width dimension, A step of preparing the aggregate having a particle structure comprising, (ii) A step of preparing a plurality of aggregate fractions by subjecting the aggregates to size classification, wherein the plurality of aggregate fractions comprises at least a first aggregate fraction having a first weight-average particle length dimension and a second aggregate fraction having a second weight-average particle length dimension, wherein the first weight-average particle length dimension is smaller than the second weight-average particle length dimension, (iii) A step of processing at least a portion of the aggregates of the first aggregate fraction to provide the fiber-containing particles having the particle structure for inclusion in a bulk product, The manufacturing process comprises, A reprocessing step of reprocessing at least a portion of the discontinuous fibers and the binder material of the second aggregate fraction, wherein the reprocessing step is (a) A step of preparing reprocessed discontinuous reinforced fibers by subjecting at least a portion, preferably all, of the aggregates of the second aggregate fraction to a length reduction treatment, thereby reducing the length of at least a portion of the discontinuous reinforced fibers of the second aggregate fraction (optionally, the length reduction treatment comprises a step of subjecting at least a portion of the second aggregate fraction to one or more cutting operations), and (b) A step of subjecting the manufacturing process at the time the reprocessing step occurs to at least a portion of the reprocessed discontinuous reinforced fibers derived from the second aggregate fraction and at least a portion of the binder material derived from the second aggregate fraction, in the manufacturing process at the time the reprocessing step occurs. The reprocessing step comprises, A method that includes [the following features].

[0136] <Clause 4> The second weight-average particle length dimension is at least 1.25 times, or at least 1.5 times, and even more than 2.0 times, the first weight-average particle length dimension. The second weight-average particle length dimension shall not exceed 10 times the first weight-average particle length dimension. The method described in Article (paragraph) 3.

[0137] <Clause 5> The first weight-average particle length is in the range of 3 millimeters to 40 millimeters. The method described in Clause 3 or Clause 4.

[0138] <Clause 6> The first aggregate fraction has a first weight-average aspect ratio. The second aggregate fraction has a second weight-average aspect ratio. The second weight-average aspect ratio is greater than the first weight-average aspect ratio. The method described in any one of clauses 3 to 5.

[0139] <Clause 7> The second weight-average aspect ratio is at least 1.25 times, or at least 1.5 times, and even at least 2.0 times, the first weight-average aspect ratio. The second weight-average aspect ratio may be arbitrarily set not to exceed 10 times the first weight-average aspect ratio. The method described in Article 6.

[0140] <Clause 8> The processing mixture in the manufacturing process at the time of the reprocessing step has a weight ratio of binder material to reprocessed discontinuous reinforced fibers that is in the range of 0.9 to 1.1, and preferably it is the same as the weight ratio of binder material to discontinuous fibers in the second aggregate fraction. The method described in any one of clauses 3 to 7.

[0141] <Clause 9> The processing mixture from the manufacturing process at the time of the reprocessing step is The amount of reprocessed discontinuous reinforced fibers is at least 90% by mass of the mass of discontinuous reinforced fibers in the second aggregate fraction, preferably the entire amount. Furthermore, the amount of binder material is at least 90% by mass of the binder material in the second aggregate fraction, preferably the entire amount. The method described in any one of clauses 3 to 8.

[0142] <Clause 10> The manufacturing process involves a processing mixture containing water in addition to discontinuous reinforcing fibers and binder material, thereby preparing aggregates containing water from the processing mixture. The processing mixture from the manufacturing process at the time of the reprocessing step contains water from the second aggregate fraction. The method described in any one of clauses 3 to 9.

[0143] <Clause 11> At least a portion of the second aggregate fraction subjected to (submitted to, subjected to) the length reduction treatment contains water in a concentration ranging from 5% by weight or more, preferably 10% by weight or more, more preferably 15% by weight or more, and 50% by weight or less, preferably 35% by weight or less, and even more preferably 30% by weight or less. The method described in Article 10.

[0144] <Clause 12> The processing mixture used in the manufacturing process at the time of the reprocessing step contains water from the second aggregate fraction in a concentration ranging from 5% by weight or more, preferably 10% by weight or more, more preferably 15% by weight or more, and 50% by weight or less, preferably 35% by weight or less, and more preferably at least 30% by weight or less. The method described in Article 10 or 11.

[0145] <Clause 13> The processing mixture used in the manufacturing process at the time of the reprocessing step consists only of water from the second aggregate fraction. The method described in Article 12.

[0146] <Clause 14> The processing mixture used in the manufacturing process at the time of the reprocessing step comprises water from the second aggregate fraction, plus additional water. The method described in Article 12.

[0147] <Clause 15> At the time of the reprocessing step, the discontinuous reinforcing fibers in the processing mixture of the manufacturing process consist only of reprocessed discontinuous reinforcing fibers prepared from at least a portion of the second aggregate fraction. The method described in any one of clauses 3 to 14.

[0148] <Clause 16> The binder material in the manufacturing process mixture at the time of the reprocessing step comprises only the binder material from at least a portion of the second aggregate fraction. The method described in any one of clauses 3 to 15.

[0149] <Clause 17> The discontinuous reinforcing fibers in the manufacturing process mixture at the time of the reprocessing step include discontinuous reinforcing fibers other than the prepared reprocessed discontinuous reinforcing fibers, which are derived from at least a portion of the second aggregate fraction. The method described in any one of clauses 3 to 14.

[0150] <Clause 18> The other discontinuous reinforcing fibers include discontinuous reinforcing fibers supplied as a dry discontinuous fiber feed to the manufacturing process when a reprocessing step occurs. The method described in Article 17.

[0151] <Clause 19> The manufacturing process includes a step of preparing the processing mixture before tumbling. The method described in any one of clauses 3 to 18.

[0152] <Clause 20> The method further comprises a step of subjecting (subjecting, providing) at least a portion of the discontinuous fibers and binder material of the second aggregate fraction prepared during the manufacturing process at the time the reprocessing step occurs. The method described in any one of clauses 3 to 19.

[0153] <Clause 21> At the time each manufacturing process occurs, the processing mixture is: It contains only discontinuous reinforced fibers that have not been subjected to reprocessing more than five times in the past. Preferably, it comprises only discontinuous reinforcing fibers that have not been subjected to a reprocessing step more than four times in the past. More preferably, the system comprises only discontinuous reinforcing fibers that have not been subjected to a reprocessing step more than three times in the past. The method described in any one of clauses 3 to 20.

[0154] <Clause 22> Bulk products generated during the manufacturing process, The bulk product of the manufacturing process at the time of the subsequent reprocessing step, It is prepared and maintained as a separate bulk product. Optionally, packaged in bags or other packaging containers, separate products The method described in any one of clauses 3 to 21.

[0155] <Clause 23> At least a portion of the bulk product at the time of the manufacturing process, At the time of the subsequent reprocessing step, at least a portion of the bulk product of the manufacturing process, It is combined (combined, assembled) as a combined bulk product. The method described in any one of clauses 3 to 21.

[0156] <Clause 24> The first aggregate fraction contains 5% by weight or more of water, preferably 10% by weight or more, and more preferably 15% by weight or more. It is provided in a concentration of 50% by weight or less, preferably 35% by weight or less, and more preferably 30% by weight or less. The method described in any one of clauses 3 to 23.

[0157] <Clause 25> Multiple aggregate fractions include a third aggregate fraction having a third weight-average particle length dimension. The third weight-average particle length dimension is greater than the first weight-average particle length dimension and smaller than the second weight-average particle length dimension. The method described in any one of clauses 3 to 24.

[0158] <Clause 26> The above method further comprises a step of reprocessing at least a portion of the third aggregate fraction, Optionally, at least a portion of the second aggregate fraction subjected to reprocessing is reprocessed separately. Alternatively, it may be reprocessed together with at least a portion of the second aggregate fraction that has been reprocessed. The method described in Article 25.

[0159] <Clause 27> The method further comprises an initial manufacturing process in which at least a portion of the discontinuous fibers for the processing mixture are supplied to the initial manufacturing process as a dry discontinuous fiber feed, The method further comprises pretreatment of reinforcing fibers for preparing the discontinuous fiber feed, The method described in any one of clauses 3 to 26.

[0160] <Clause 28> The aforementioned preliminary treatment is A step of preparing a plurality of fiber fractions comprising at least a first fiber fraction (having a first weight-average fiber length) and a second fiber fraction (having a second weight-average fiber length, the second weight-average fiber length being greater than the first weight-average fiber length) by size classifying the mixture of the discontinuous reinforced fibers, and The steps include preparing the discontinuous fiber supply so that it comprises at least a portion of the discontinuous reinforcing fibers of the first fiber fraction, The method described in Clause 2 or Clause 27, which includes the provision described in Clause 2.

[0161] <Clause 29> The second weight-average fiber length is at least 1.25 times, or at least 1.5 times, and even at least 2.0 times, the first weight-average fiber length. Optionally, the second weight-average fiber length shall not exceed 10 times the first weight-average fiber length. The method described in either Clause 1 or Clause 28.

[0162] <Clause 30> The first weight-average fiber length is at least 1 millimeter, preferably at least 2 millimeters, more preferably at least 3 millimeters, or even further at least 4 millimeters, or at least 6 millimeters, or at least 9 millimeters. The method described in any one of Clause 1, Clause 28, or Clause 29.

[0163] <Clause 31> The first weight-average fiber length is 18 mm or less, preferably 12 mm or less, more preferably 8 mm or less, or even more preferably 6 mm or less. One preferred range for the first weight-average fiber length is 3 mm to 8 mm, and another preferred range is 4 mm to 12 mm. The method described in any one of Clause 1 and Clauses 28-30.

[0164] <Clause 32> Multiple fiber fractions include a third fiber fraction having a third weight-average fiber length. The third weight-average fiber length is smaller than the first weight-average fiber length. The method described in any one of Clause 1 and Clauses 28-31.

[0165] <Clause 33> The first weight-average fiber length is at least 1.25 times the third weight-average fiber length, or at least 1.5 times the third weight-average fiber length. Furthermore, it is at least 2.0 times the third weight-average fiber length. The first weight-average fiber length shall not exceed 50 times the third weight-average fiber length. The method described in Article 32.

[0166] <Clause 34> The third weight-average fiber length is 2 millimeters or less, or 1.5 millimeters or less, or 1 millimeter or less. Optionally, the third weight-average fiber length is at least 0.1 millimeters. The method described in Article 32 or 33.

[0167] <Clause 35> The method further comprises the step of removing at least a portion, preferably all, of the third fiber fraction from the discontinuous fiber feed and aggregates. The method described in any one of clauses 32 to 34.

[0168] <Clause 36> At least a portion, preferably all, of the first fiber fraction forms at least a portion of the discontinuous fiber feed. Optionally, after size classification and before being included in the discontinuous fiber supply, without modification of the fibers, The method described in any one of Clause 1 and Clauses 28-35.

[0169] <Clause 37> At least a portion, preferably all, of the first fiber fraction forms at least a portion of the discontinuous fiber feed. The step of preparing the discontinuous fiber feed by processing at least a portion of the first fiber fraction does not involve length reduction treatment of the fibers in the first fiber fraction. The method described in any one of Clause 1 and Clauses 28-36.

[0170] <Clause 38> The discontinuous fiber feed is prepared such that the weight-average fiber length in the discontinuous fiber feed is at least 1 millimeter, preferably at least 2 millimeters, more preferably at least 3 millimeters, or even further at least 4 millimeters, or at least 6 millimeters, or at least 9 millimeters. The method described in any one of Clause 1 and Clauses 28-37.

[0171] <Clause 39> The discontinuous fiber supply has a weight-average fiber length of 18 mm or less, preferably 12 mm or less, more preferably 8 mm or less, or even more preferably 6 mm or less. The first weight-average fiber length is prepared such that one preferred range is 3 mm to 8 mm, and the other preferred range is 4 mm to 12 mm. The method described in any one of Clause 1 and Clauses 28-38.

[0172] <Clause 40> The method further comprises a step of preparing fibers with reduced length by subjecting at least a portion of the second fiber fraction to a fiber length reduction treatment. The system optionally includes a step for cutting the fibers of the second fiber fraction. The method described in any one of Clause 1 and Clauses 28-39.

[0173] <Clause 41> The method further comprises the step of preparing the discontinuous fiber feed to comprise at least a portion of the length-reducing fibers. The method described in Article 40.

[0174] <Clause 42> The method further comprises a step of recycling at least a portion of the length-reduced fibers and including them in a mixture of discontinuous reinforced fibers to be subjected to size classification. The method described in Article 41.

[0175] <Clause 43> The method further comprises a step of preparing a mixture of discontinuous fibers, The step of preparing the aforementioned mixture includes subjecting a preliminary mixture of reinforcing fibers to a length reduction treatment. Optionally, the length reduction process comprises one or more cutting steps, and the weight-average fiber length of the discontinuous reinforcing fiber mixture is less than the weight-average fiber length of the pre-mixture of reinforcing fibers. The method described in any one of Clause 1 and Clauses 28-42.

[0176] <Clause 44> The method further comprises a step of recycling at least a portion of the second fiber fraction into a preliminary mixture of reinforcing fibers, The mixture of discontinuous reinforced fibers comprises length-reduced fibers prepared from regenerated fibers of the second fiber fraction. The method described in Article 43.

[0177] <Clause 45> The discontinuous fiber supply is the first discontinuous fiber supply, The aggregate is the first aggregate, The aforementioned binder material is the first binder material, The aforementioned reinforcing fiber is the first reinforcing fiber, The aforementioned treatment mixture is the first treatment mixture, The tumbling is a first tumbling, and the method further, A step of preparing a second discontinuous fiber supply separately from the first discontinuous fiber supply, wherein the second discontinuous fiber supply comprises second reinforcing fibers, and the second reinforcing fibers comprises at least some, preferably all, length-reducing fibers, and A step of preparing a second aggregate comprising at least a portion of the second discontinuous fiber feed and a second binder material, comprising: mixing the second discontinuous fiber feed and the second binder material in a second treatment mixture; and subjecting the second treatment mixture to a second tumbling, It is equipped with, Optionally, the second binder material may have the same composition as the first binder material. Furthermore, optionally, the first binder material may have a different composition from the first binder material. The method described in Article 40.

[0178] <Clause 46> Each of the second discontinuous fiber feed, second aggregate, second binder material, second reinforcing fiber, and second tumbling has the characteristics or properties described in any preceding or succeeding clause with respect to the first aggregate, first binder material, first reinforcing fiber, first tumbling, or first treatment mixture. The method described in Article 45.

[0179] <Clause 47> The aforementioned size classification comprises air classification, vibratory sorting, screening, or any combination thereof. The method described in any one of Clause 1 and Clauses 28-46.

[0180] <Clause 48> The aforementioned preliminary treatment is A process for preparing an aligned fiber supply by increasing the degree to which the reinforcing fibers are aligned longitudinally with respect to each other, and A step of preparing the discontinuous fiber supply so that it comprises at least a portion of the reinforcing fibers of the aligned fiber supply, The method described in any one of Clause 1 and Clauses 27-47, comprising:

[0181] <Clause 49> The process for preparing the discontinuous fiber supply includes a step of reducing the weight-average length of the reinforcing fibers before increasing their longitudinal alignment by subjecting them to an upstream length reduction process. Optionally, the upstream length reduction process includes a cutting operation, preferably the reinforcing fiber has a cutting blade positioned laterally to the machine transport direction when passing through the upstream cutting operation. The method described in Clause 2 or Clause 48.

[0182] <Clause 50> The process for preparing a discontinuous fiber feed includes a step of reducing the weight-average length of the reinforcing fibers by subjecting the reinforcing fibers in the aligned fiber feed to a downstream length reduction treatment. Optionally, the downstream length reduction process includes a cutting step, and preferably has a cutting blade arranged transversely to the mechanical conveying direction when the reinforcing fibers pass through the downstream cutting step. The method according to any one of clause 2, clause 48 and clause 49.

[0183] <clause 51> The step of preparing the discontinuous fiber supply includes preparing a plurality of fiber fractions including at least a first fiber fraction having a first weight average fiber length and a second fiber fraction having a second weight average fiber length greater than the first weight average fiber length by size-classifying the mixture of discontinuous fibers from the downstream length reduction process; and preparing a discontinuous fiber supply so as to include at least a part of the discontinuous reinforcing fibers of the first fiber fraction. The method according to clause 50, comprising

[0184] <clause 52> The step of increasing the longitudinal alignment between reinforcing fibers increases the longitudinal alignment of the reinforcing fibers with respect to the mechanical conveying direction of the reinforcing fibers towards the downstream length reduction process of the reinforcing fibers. The method according to clause 50 or 51.

[0185] <clause 53> The step of increasing the longitudinal alignment includes the step of bringing at least a part of the reinforcing fibers into contact with an alignment channel extending along the mechanical conveying direction of the reinforcing fibers during the conveyance of the reinforcing fibers. The alignment channel is configured to increase the alignment degree between the reinforcing fibers, and optionally, the alignment channel is configured to increase the longitudinal alignment between the reinforcing fibers with respect to the mechanical conveying direction in which the reinforcing fibers are conveyed in the step of increasing the longitudinal alignment. The method according to any one of clause 2 and clauses 48 to 52.

[0186] <clause 54> The alignment channel includes a channel on a vibrating conveyor. The method according to item 53.

[0187] <Item 55> The alignment channel has a channel width in a direction perpendicular to the mechanical conveyance direction (the mechanical direction of conveyance), The channel width is at least 1 millimeter, at least 2 millimeters, at least 4 millimeters, or at least 6 millimeters. The method according to item 53 or 54.

[0188] <Item 55.1> The alignment channel has a channel width in a direction perpendicular to the mechanical conveyance direction, The channel width is 45 millimeters or less, 30 millimeters or less, 20 millimeters or less, or 10 millimeters or less, One preferred range of the channel width of the alignment channel is 2 millimeters to 10 millimeters. The method according to any one of items 53 to 55.

[0189] <Item 56> The alignment channel has a channel length in the longitudinal direction along the mechanical conveyance direction, The channel length is at least 20 centimeters, at least 30 centimeters, at least 50 centimeters, or at least 75 centimeters. The method according to any one of items 53 to 55.1.

[0190] <Item 56.1> The alignment channel has a channel length along the mechanical conveyance direction, The channel length is 500 centimeters or less, 300 centimeters or less, 200 centimeters or less, or 100 centimeters or less, One preferred range of the channel length of the alignment channel is 75 centimeters to 100 centimeters. The method according to any one of items 53 to 56.

[0191] <Clause 56.2> The process for increasing longitudinal alignment includes, during the transport of the reinforcing fibers, bringing at least a portion of the reinforcing fibers into contact with alignment slots that extend along the mechanical transport direction of the reinforcing fibers. The alignment slots are configured to increase the degree of alignment of the reinforcing fibers passing through them by allowing the reinforcing fibers to pass through the alignment slots. Optionally, the alignment slots are configured to increase the longitudinal alignment of the reinforcing fibers passing through the alignment slots with respect to the machine transport direction in a process of increasing longitudinal alignment. The method described in any one of Clause 2 and Clauses 48 to 56.1.

[0192] <Clause 56.3> The alignment slots are located on a vibrating conveyor. The method described in Clause 56.2.

[0193] <Clause 56.4> The alignment slots have a slot width perpendicular to the machine transport direction. The slot width is at least 2 mm, at least 3 mm, at least 4 mm, or at least 5 mm. The method described in Clause 56.2 or Clause 56.3.

[0194] <Clause 56.5> The alignment slots have a slot width perpendicular to the machine transport direction. The slot width is 45 mm or less, 30 mm or less, 20 mm or less, or 10 mm or less. One preferred range for the slot width of the aforementioned alignment slot is 5 mm to 10 mm. The method described in any one of the clauses 56.2 to 56.4.

[0195] <Clause 56.6> The alignment slots have a slot length aligned with the machine transport direction. The slot length is at least 20 centimeters, at least 30 centimeters, at least 50 centimeters, or at least 75 centimeters. The method according to any one of Clauses 56.2 to 56.5.

[0196] <Clause 56.7> The alignment slot has a slot length along the mechanical conveyance direction. The slot length is 500 centimeters or less, 300 centimeters or less, 200 centimeters or less, or 100 centimeters or less. One preferred range of the slot length of the alignment slot is 75 centimeters to 100 centimeters. The method according to any one of Clauses 56.2 to 56.6.

[0197] <Clause 57> The step of increasing the longitudinal alignment of the reinforcing fibers includes a step of increasing the longitudinal alignment of the reinforcing fibers from a first alignment state to a second alignment state. In the second alignment state, the reinforcing fibers are more aligned in the mechanical conveyance direction of the reinforcing fibers. The method according to any one of Clause 2 and Clauses 48 to 56.7.

[0198] <Clause 57.1> In the first alignment state, at least 30% in length, and further at least 40% in length, of the reinforcing fibers are longitudinally oriented (longitudinal orientation) at an alignment angle of 45° to 90° with respect to the mechanical conveyance direction. In the second alignment state, 20% or less in length, and further 10% or less in length, of the reinforcing fibers are longitudinally oriented at an alignment angle of 45° to 90° with respect to the mechanical conveyance direction. The method according to Clause 57.

[0199] <Clause 57.2> In the first alignment state, at least 15% by weight, and further at least 20% in length, of the reinforcing fibers are longitudinally oriented at an alignment angle of 60° to 90° with respect to the mechanical conveyance direction. In the second alignment state, less than 10% by weight of the reinforcing fibers, and moreover less than 5% by length, are oriented longitudinally at an alignment angle of 60° to 90° with respect to the machine conveying direction. The method described in Clause 57 or Clause 57.1.

[0200] <Clause 57.3> In the first alignment state, less than 40% of the reinforcing fibers, and moreover less than 35% of the reinforcing fibers, are oriented longitudinally at an alignment angle of 0° to 30° with respect to the machine conveying direction. In the second alignment state, at least 70% of the length of the reinforcing fibers, and moreover at least 80% of the length, are oriented longitudinally at an alignment angle of 0° to 30° with respect to the machine conveying direction. The method described in any one of the clauses 57 to 57.2.

[0201] <Clause 57.4> In the first alignment state, the reinforcing fibers have a length-average alignment angle greater than 35°, and even greater than 40°, with respect to the machine transport direction. In the second alignment state, the reinforcing fibers have a length-average alignment angle of 20° or less, and moreover, 10° or less, with respect to the machine transport direction. The method described in any one of the clauses 57 to 57.3.

[0202] <Clause 58> The preparation of the fiber feed involves increasing the longitudinal alignment (degree of longitudinal alignment), A step of preparing a plurality of fiber fractions by size classifying reinforcing fibers, wherein each fraction comprises at least a first fiber fraction having a first weight-average fiber length and a second fiber fraction having a second weight-average fiber length, wherein the second weight-average fiber length is greater than the first weight-average fiber length, and A step of preparing a discontinuous fiber feed such that it comprises at least a portion of the discontinuous reinforcing fibers of the first fiber fraction, It is equipped with The method described in any one of Clause 2 and Clauses 48 to 57.4.

[0203] <Clause 59> Pre-treatment of reinforcing fibers is The process involves preparing cut fibers by cutting the reinforcing fibers, A step of preparing the fiber supply so that it comprises at least a portion of the cut fibers, It is equipped with The method described in any one of Clause 1, Clause 2, and Clauses 27-58.

[0204] <Clause 60> The preliminary fiber supply used for preliminary processing comprises recycled reinforced fibers recovered from composite materials. The method described in any one of Clause 1, Clause 2, and Clauses 27-59.

[0205] <Clause 61> The method further includes a step of recovering (recovering) regenerated reinforced fibers from the composite material. The process for recovering the regenerated reinforced fibers includes a step of separating (freeing) the regenerated reinforced fibers from the matrix of the composite material. The method optionally includes dissolution of the matrix of the composite material, optional thermal decomposition (pyrolysis) of the matrix of the composite material, and optional depolymerization of the matrix of the composite material. The method described in Article 60.

[0206] <Clause 62> The weight-average fiber length of the reinforcing fibers in the fiber supply is at least 1 mm, at least 2 mm, at least 3 mm, at least 4 mm, at least 6 mm, or even more than 9 mm. The method described in any one of Clause 1, Clause 2, and Clauses 27-61.

[0207] <Clause 63> The weight-average fiber length of the reinforcing fibers in the fiber supply is 18 mm or less, 12 mm or less, 8 mm or less, or 6 mm or less. The method described in any one of Clause 1, Clause 2, and Clauses 27-62.

[0208] One preferred range for the weight-average fiber length in the fiber feed is 3 mm to 8 mm. Another preferred range is 4 mm to 6 mm.

[0209] <Clause 64> The reinforcing fibers in the fiber supply have not undergone fiber sizing treatment. The method described in any one of Clause 1, Clause 2, and Clauses 27-63.

[0210] <Clause 65> The reinforcing fibers have undergone fiber sizing treatment. Optionally, the amount of the fiber sizing treatment, including the weight of the fiber sizing, is within the range of 0.5% to 10% by weight of the reinforcing fibers. The method described in any one of Clause 1, Clause 2, and Clauses 27-64.

[0211] <Clause 66> The tumbling features a rotating tumbling mechanism. Optionally, the preparation of aggregates includes the step of placing reinforcing fibers and binder material in a processing vessel (e.g., a rotating drum), Rotary tumbling involves a process of rotating a processing vessel containing reinforcing fibers and binder material. The method described in any one of the clauses 1 to 65.

[0212] <Clause 67> Rotary tumbling involves a process of rotating the processing container at a tangential speed (chip speed) of the processing container on the inner surface of the rotating wall in the range of 0.3 to 1.4 meters per second. The method described in Article 66.

[0213] <Clause 68> Tumbling takes place over a period of time ranging from 15 to 240 minutes. The method described in any one of clauses 1 to 67. A more preferred time period is between 120 and 150 minutes.

[0214] <Clause 69> The supply of binder material for preparing aggregates comprises a binder precursor composition (prequeser composition) comprising binder material dispersed in a carrier liquid. The method described in any one of the clauses 1 to 68.

[0215] <Clause 70> The binder precursor composition comprises at least a portion of the binder material in a solid component dispersed in a carrier liquid. The method described in Article 69.

[0216] <Clause 71> The preparation of aggregates includes a step of combining all or part of the binder precursor composition with reinforcing fibers before rotary tumbling (for example, a step of pre-mixing the binder material and reinforcing fibers before introducing them into the processing vessel). The method described in Clause 69 or Clause 70.

[0217] <Clause 72> The preparation of aggregates comprises the steps of introducing reinforcing fibers into a processing vessel (e.g., a rotating drum), followed by introducing part or all of the binder precursor composition into the processing vessel. The binder precursor composition is introduced while the processing container is rotated as needed. Optionally, the binder precursor composition is sprayed into the processing container to come into contact with and mix with the reinforcing fibers. The method described in any one of the clauses 69 to 71.

[0218] <Clause 73> The method further comprises the step of bringing the binder precursor composition into contact with the reinforcing fibers, and then evaporating at least a portion of the carrier liquid. Optionally, evaporate during and / or after tumbling. Preferably, at least a portion, and more preferably most, of the evaporation is carried out after rotary tumbling. The method described in any one of clauses 69 to 72.

[0219] <Clause 74> Evaporation involves a step of heating the reinforcing fibers and carrier liquid. At a temperature of at least 100°C, Furthermore, it is heated to a temperature of any choice in the range of 100°C to 200°C, This does not involve post-drying heat curing, and is used in some binding systems such as thermosetting binder compositions and ultra-high temperature thermoplastic binder compositions. The method described in Article 73.

[0220] If the method includes curing of the binder material, the dried aggregate may be exposed to a temperature higher than the temperature used for drying for curing, for example, the curing temperature may exceed 200°C and often be in the range of 200°C to 380°C. As mentioned above, drying and curing may be performed in a single operation (e.g., in a single oven), in which case, Drying is carried out by evaporating the water through the first stage of heating in a low-temperature range (low-elevated tempera challenge). Curing may be carried out by a second stage of heating (for curing) in a high temperature range. Alternatively, drying and curing may be carried out in separate operations (e.g., in separate ovens).

[0221] <Clause 75> The carrier liquid is an aqueous liquid. The method described in any one of clauses 69 to 74.

[0222] <Clause 76> The preparation of aggregates involves a step of combining the binder material, reinforcing fibers, and water before the completion of tumbling. The water is, relative to the total weight of the binder material, reinforcing fibers, and water, The lower limit is 10% by weight or more, more preferably 20% by weight or more. The upper limit is 50% by weight or less, more preferably 30% by weight or less. It exists at concentrations within the range of, The method described in any one of the clauses 1 to 75.

[0223] <Clause 77> The binder material in the processed mixture is present in an amount of 0.5% to 11% by weight relative to the weight of the reinforcing fibers. The method described in any one of the clauses 1 to 76.

[0224] <Clause 78> The binder material in the processed mixture is, relative to the weight of the reinforcing fibers, The lower limit is a value selected from the group consisting of 0.5% by weight, 1% by weight, 2% by weight, 2.5% by weight, and 3% by weight. The upper limit lies within a range of values ​​selected from the group consisting of 11% by weight, 9% by weight, 7% by weight, 6% by weight, and 5% by weight. The method described in any one of clauses 1 to 77. In one preferred range, the binder material is 2% to 6% by weight relative to the weight of the reinforcing fibers. In other preferred ranges, the binder material is 2.5% to 5% by weight relative to the weight of the reinforcing fibers.

[0225] <Clause 79> The binder material comprises a material selected from the group consisting of polyether polyurethane resin (uncured), polyester polyurethane resin (uncured), maleated polypropylene, polyarylether ketone (PAEK), or epoxy resin (uncured). The method described in any one of the clauses 1 to 78.

[0226] <Clause 80> The above method further comprises a step of preparing a dried aggregate by drying the aggregate, wherein the dried aggregate contains 0.5% by weight or less of water, preferably 0.3% by weight or less, and more preferably 0.2% by weight or less. The dried aggregate optionally contains 0.001% by weight or more, and furthermore, 0.01% by weight or more of water. The method described in any one of the clauses 1 to 79.

[0227] <Clause 81> Tumbling involves a process for aligning reinforcing fibers. Rotational tumbling is performed for a period of time to align the reinforcing fibers in the aggregate into an alignment configuration. In the aforementioned alignment configuration, at least 70% by weight, preferably at least 80% by weight, and more preferably at least 85% by weight of the reinforcing fibers extend in the longitudinal direction at an angle of 20° or less with respect to the longitudinal direction of the aggregate, preferably at an angle of 15° or less, and more preferably at an angle of 10° or less. The method described in any one of the clauses 1 to 80.

[0228] <Clause 82> The method further comprises a step of removing liquid from aggregate particles by drying the aggregates after achieving the alignment configuration. The method described in Article 81.

[0229] <Clause 83> The preparation of aggregates is as follows: A step in which aggregates are formed as particles having a particle structure during tumbling, wherein the particle structure is The particle length dimension is the maximum separation distance in the longitudinal direction between the first longitudinal end and the second longitudinal end of the particle, The maximum particle width dimension is the maximum dimension in the lateral direction relative to the longitudinal direction at the longitudinal position between the first longitudinal end and the second longitudinal end, The aspect ratio is the value obtained by dividing the particle length by the maximum particle width, and The process of forming aggregates, which includes the following steps: A step of recovering a batch of aggregates, which contains at least a portion of the aggregates, as batch particles, It is equipped with The method described in any one of the clauses 1 to 82.

[0230] <Clause 84> The method further comprises the step of processing at least a portion of a batch of aggregates to prepare a batch of bulk products comprising a plurality of fiber-containing particles having the particle structure. The method described in Article 83.

[0231] <Clause 85> The process of processing at least a portion of the aggregate batch includes a step of drying at least a portion of the particles in the aggregate batch to reduce the moisture content to 0.5% by weight or less, preferably 0.3% by weight or less, more preferably 0.2% by weight or less, and optionally further drying to a moisture content of 0.001% by weight or more, and even more preferably 0.01% by weight or more. The method described in Article 84.

[0232] <Clause 86> The drying process includes a step of drying at least a portion of the first aggregate fraction at a temperature of 100°C or higher. Drying is performed at a range of 100°C to 200°C, but this does not involve post-drying heat curing, which is used in some binding systems such as thermosetting binder compositions and ultra-high temperature thermoplastic binder compositions. The method described in Article 85.

[0233] <Clause 87> The method further comprises a step of curing the dried aggregate particles at a temperature in the range of 200°C to 380°C after drying. The method described in either Clause 85 or Clause 86.

[0234] <Clause 88> For batches of aggregates or batches of bulk products, or both, At least 25% by weight of the particles in the batch have a dual tapered shape, and the dual tapered shape is A first tapered tip that tapers longitudinally from the longitudinal position toward the first longitudinal end, A second tapered end that tapers longitudinally from the longitudinal position toward the second longitudinal end, It is equipped with, Optionally, at least 50% by weight, 75% by weight, or 90% by weight of the particles in the batch have a dual tapered shape. Furthermore, optionally, at least 10% by weight of the particles in the batch do not have a dual tapered shape. The method described in any one of the clauses 84 to 87.

[0235] <Clause 89> The first and second tapered sections each taper within the tapered envelope of the right cone over a longitudinal distance of at least 20% (preferably at least 25%) of the longitudinal length. The tapered envelope of a right cone has a vertex at the corresponding longitudinal end. The opening angle of the tapered envelope of the right cone is 45° or less, preferably 40° or less, more preferably 37° or less, and even more preferably 35° or less, and in any case the opening angle is at least 10°. The method described in Clause 88. One preferred range of opening angles is 14° to 34°.

[0236] <Clause 90> For each batch of aggregates and batch of bulk products, the batch is: The weight-average particle length dimension is the weight-average of the particle length dimensions of the particles in the batch, The weight-average aspect ratio is the weight-average aspect ratio of the particles in the batch, The method described in any one of clauses 88 to 89, which includes the provision.

[0237] <Clause 91> For either or both batches of aggregates and / or bulk products, the weight-average particle length dimension is within a range having a lower limit selected from the group consisting of 3 mm, 3.5 mm, 4 mm, 5 mm, and 6 mm. The method described in Article 90.

[0238] <Clause 92> For either or both batches of aggregates and batches of bulk products, the weight-average particle length dimension is within a range having an upper limit selected from the group consisting of 40 mm, 30 mm, 20 mm, 16 mm, and 14 mm. One preferred range for weight-average particle length dimension is 5 mm to 16 mm, and a more preferred range is 6 mm to 14 mm. The method described in Article 90 or 91.

[0239] <Clause 93> For either or both batches of aggregates and batches of bulk products, at least 75% by weight, preferably at least 80% by weight, more preferably at least 85% by weight, and even more preferably at least 90% by weight of fiber-containing particles have a particle length dimension of: A lower limit of 0.5 times (preferably 0.7 times) the weight-average particle length dimension, An upper limit of twice (preferably 1.8 times) the weight-average particle length dimension, and within the range of, The method described in any one of clauses 90 to 92.

[0240] <Clause 94> For either or both batches of aggregates and / or bulk products, the particle length dimension of at least 2% by weight, or at least 5% by weight, or even at least 10% by weight, of the fiber-containing particles is outside the range of 0.8 to 1.2 times the weight-average particle length dimension. The method described in any one of clauses 90 to 93.

[0241] <Clause 95> For either or both batches of aggregates and / or bulk products, the particle length dimension of at least 98% by weight of fiber-containing particles is no more than three times the weight-average particle length dimension. The method described in any one of clauses 90 to 94.

[0242] <Clause 96> For either or both batches of aggregates and / or bulk products, the weight-average aspect ratio is within a range having a lower limit selected from the group consisting of 1.5, 1.7, 1.8, and 1.9. The method described in any one of the clauses 90 to 95.

[0243] <Clause 97> For either or both batches of aggregates and / or bulk products, the weight-average aspect ratio is within a range having an upper limit selected from the group consisting of 6, 4, and 3. The method described in any one of clauses 90 to 96. A preferred weight-average aspect ratio range is 1.8 to 4.

[0244] <Clause 98> For either or both batches of aggregates and batches of bulk products, the aspect ratio of at least 75% by weight, preferably at least 80% by weight, more preferably at least 85% by weight, and even more preferably at least 90% by weight of fiber-containing particles is within a range of 4 with a lower limit of 1.5. The method described in any one of the clauses 90 to 97.

[0245] <Clause 99> For either or both batches of aggregates and / or bulk products, the aspect ratio of at least 2% by weight of fiber-containing particles, or at least 5% by weight, is outside the range of 0.8 to 1.2 times the weight-average aspect ratio. The method described in any one of the clauses 90 to 98.

[0246] <Clause 100> A method for manufacturing a fiber-reinforced composite material, the method comprising a dispersion step of dispersing reinforcing fibers from fiber-containing particles of a batch of bulk products described in any one of clauses 90 to 99 into a matrix, The matrix is ​​preferably a polymer matrix. Optionally, the resulting composite material contains 5% to 50% by weight of reinforcing fibers. A method comprising 10% to 40% by weight of reinforcing fibers as one preferred range.

[0247] <Clause 101> The matrix is ​​a polymer matrix comprising a thermoplastic polymer. The method described in Article 100.

[0248] <Clause 102> The thermoplastic polymer comprises components (members) selected from the group consisting of polyamide, polypropylene, polyethylene, polyethylene terephthalate, polylactic acid, polycarbonate, acrylonitrile butadiene styrene, polystyrene, and polyaryl ether ketone. The method described in Article 101.

[0249] <Clause 103> The reinforcing fiber dispersion process is, An extrusion process for extruding polymer material for the matrix, A step of adding fiber-containing particles of the bulk product batch to the polymer material during the extrusion process, It is equipped with The method described in Article 101 or 102.

[0250] <Clause 104> The method further comprises a step of preparing pellets containing reinforcing fibers dispersed in a matrix by pelletizing the extruded material from the extrusion process, thereby ensuring that the extruded material contains reinforcing fibers dispersed in a matrix. Optionally, the pellets have a maximum cross dimension (e.g., length dimension) in the range of 1 mm to 25 mm, preferably in the range of 4 mm to 18 mm. Furthermore, optionally, the pellets have a width dimension ranging from 1 mm to 6 mm, preferably 2 to 4 mm, in a direction perpendicular (transverse) to the maximum crossing dimension. Preferably, the pellets are cylindrical, and the cylindrical length and cylindrical diameter are within the range of the maximum tolerance dimension and the width dimension, preferably within a desirable range. The method described in Article 103.

[0251] <Clause 105> The method further comprises a step of cooling the extruded material before pelletization. The method described in Article 104.

[0252] <Clause 106> The method further comprises the step of mixing the pellets with at least one other granular component different from the pellets, Optionally, the other granular components comprise second pellets of a different composition. Furthermore, optionally, the second pellet comprises second reinforcing fibers, which may be the same as or different from the reinforcing fibers of the pellet, and are dispersed in the second matrix. Preferably, the second matrix is ​​a second polymer matrix, and the second matrix may be the same as or different from the matrix of the pellet. Furthermore, optionally, the second reinforcing fiber may be a uniform fiber length cut from a continuous fiber. The method described in Article 104 or 105.

[0253] <Clause 107> The above method includes a step of forming a product form by molding the pellet material. The method described in any one of clauses 104 to 106.

[0254] <Clause 108> The molding process includes injection molding. The method described in Article 107.

[0255] <Clause 109> Batch of bulk products has a free-settling (untapped) bulk density, with the lower limit of the range selected from the group consisting of 100, 200, or 250 g / L, and the upper limit selected from the group consisting of 400 g / L or 350 g / L. The method described in any one of clauses 90 to 108. One preferred range of free-settling bulk density is 200 to 300 g / L.

[0256] <Clause 110> Bulk product batches have a tap bulk density (bulk density). The lower limit of the range is selected from the group consisting of 200, 250, or 300 g / L (liters). The upper limit was selected from groups consisting of 650 or 600 g / L. Arbitrarily, the tapped bulk density is in the range of 1.2 to 2 times the free-settling (untapped) bulk density. The method described in any one of clauses 84 to 109. A preferred range for tap bulk density is 250 to 400 g / L.

[0257] <Clause 111> A batch of bulk products comprises at least 50% by weight, preferably at least 70% by weight, more preferably at least 90% by weight, even more preferably at least 95% by weight, and even more preferably at least 98% by weight of fiber-containing particles. The method described in any one of clauses 90 to 110. Optionally, a batch of bulk products comprises only fiber-containing particles, or substantially only fiber-containing particles.

[0258] <Clause 112> Bulk product batches have an angle of repose, with a lower limit of 25° and an upper limit of 45°. One more preferable angle of repose range is 30° to 40°. The method described in any one of the clauses 88 to 111.

[0259] <Clause 113> Batch of bulk products The lower limit was selected from the groups consisting of 91% by weight, 92% by weight, and 93% by weight. The upper limit includes an amount of reinforcing fiber that is within a range selected from the group consisting of 99% by weight, 98% by weight, and 97% by weight. The method described in any one of clauses 90 to 112.

[0260] <Clause 114> Batch of bulk products The lower limit was selected from the group consisting of 1% by weight, 2% by weight, 2.5% by weight, and 3% by weight. The upper limit is selected from the group consisting of 9% by weight, 7% by weight, 6% by weight, and 5% by weight, and includes an amount of binder within that range. The method described in any one of clauses 90 to 113. One preferred range is 2% by weight to 6% by weight of binder, and the other preferred range is 2.5% by weight to 5% by weight of binder.

[0261] <Clause 115> The binder comprises a material selected from the group consisting of polyether polyurethane (preferably cured), polyester polyurethane (preferably cured), maleated polypropylene, polyarylether ketone (PAEK), and epoxy polymer (preferably cured). The method described in Article 114.

[0262] <Clause 116> The batch of bulk products features a configuration in which reinforcing fibers are aligned within the fiber-containing particles. At least 70% by weight, preferably at least 80% by weight, and more preferably at least 85% by weight of the reinforcing fibers within each fiber-containing particle extend in the longitudinal direction at an angle of 20° or less with respect to the longitudinal direction, and preferably at an angle of 10° or less. The method described in any one of the clauses 90 to 115.

[0263] <Clause 117> For either or both batches of aggregates and / or bulk products, the weight-average fiber length of the reinforcing fibers in the batch is smaller than the weight-average particle length dimension, preferably 75% or less, and often 60% or less, of the weight-average particle length dimension. The method described in any one of the clauses 90 to 116.

[0264] <Clause 118> For either or both batches of aggregates and / or bulk products, the weight-average fiber length is 20% or more, preferably 25% or more, and often 30% or more, of the weight-average particle length dimension. The method described in Article 117.

[0265] <Clause 119> The weight-average fiber length is greater than or equal to a value selected from the group consisting of 1 millimeter, 2 millimeters, 3 millimeters, and 4 millimeters. The method described in Clause 117 or Clause 118.

[0266] <Clause 120> For either the aggregate batch or the bulk product batch, or both, the weight-average fiber length is less than or equal to a value selected from the group consisting of 18 mm, 12 mm, 8 mm, and 6 mm. The method described in any one of clauses 117 to 119. For either or both batches of aggregates and / or batches of bulk products, one preferred weight-average fiber length range is 3 mm to 8 mm, and the other preferred range is 4 mm to 6 mm.

[0267] <Clause 121> For either or both of the batch of aggregates and the batch of bulk products, at least 70% by weight, preferably at least 75% by weight, more preferably at least 80% by weight, and even more preferably at least 85% by weight of the reinforcing fibers in the batch have a fiber length in the range of 0.5 to 2 times the weight-average fiber length of the batch. The method described in any one of the clauses 117 to 120.

[0268] <Clause 122> For either or both of the batch of aggregates and the batch of bulk products, at least 10% by weight of the reinforcing fibers in the batch have a fiber length that is outside the range of 0.7 to 1.5 times the weight-average fiber length. The method described in any one of the clauses 117 to 121.

[0269] <Clause 123> For either or both of the batch of aggregates and the batch of bulk products, at least 5% by weight of the reinforcing fibers in the batch have a fiber length that lies outside the range of 0.5 to 2 times the weight-average fiber length. The method described in any one of clauses 117 to 122.

[0270] <Clause 124> For either or both of the batch of aggregates and the batch of bulk products, at least 15% by weight of the reinforcing fibers in the batch have a fiber length that is outside the range of 0.8 to 1.3 times the weight-average fiber length. The method described in any one of the clauses 117 to 123.

[0271] <Clause 125> For either or both of the batch of aggregates and the batch of bulk products, the reinforcing fibers in the batch have a weight-average aspect ratio of fiber length to fiber width of at least 100, preferably at least 500, and more preferably at least 1000. The method described in any one of clauses 117 to 124.

[0272] <Clause 126> For either or both of the batch of aggregates and the batch of bulk products, the reinforcing fibers in the batch have a weight-average aspect ratio of fiber length to fiber width of 10,000 or less. The method described in any one of the clauses 117 to 125.

[0273] <Clause 127> For either or both batches of aggregates and / or bulk products, the reinforcing fibers have a weight-average fiber width (e.g., diameter) in the range of 0.5 μm to 100 μm. The method described in any one of the clauses 84 to 126.

[0274] <Clause 128> The aforementioned reinforcing fiber is carbon fiber, The carbon fiber may optionally have a width (e.g., diameter) in the range of 5 μm to 10 μm, preferably in the range of 5 μm to 7 μm. The method described in any one of the clauses 1 to 127.

[0275] <Clause 129> The reinforcing fibers are selected from the group consisting of glass fibers, mineral fibers, natural fibers, carbon nanotubes, polymer fibers (e.g., aramid, polyamide, or polyolefin fibers), metal fibers, and combinations thereof. The method described in any one of Clauses 1 to 128. Possible polyolefin fibers include polypropylene, polyethylene, and propylene-ethylene copolymer fibers, and may include high-performance polyolefin fibers, such as Dyneema® fibers (ultra-high molecular weight polyethylene) or Innegra fibers (high modulus polypropylene). Possible mineral fibers include basalt, mineral wool, or quartz fibers. Possible natural fibers include bamboo, flax, hemp, jute, or kenaf fibers. Examples of metallic fibers include fibers of metals, metal alloys, or intermetallic compounds, more specifically, steel or bronze fibers.

[0276] <Clause 130> The reinforcing fibers include recycled fibers recovered from fiber-reinforced composite materials. The method described in any one of the clauses 1 to 129.

[0277] The terms “comprising,” “containing,” “including,” and “having,” as well as their grammatical variations, have a comprehensive and non-restrictive meaning. The use of such terms indicates the existence of the described condition or feature, but does not exclude the existence of other conditions or features. When the terms “comprising,” “containing,” “including,” and “having,” as well as their grammatical variations, are used to refer to the existence of one or more components, subcomponents, or materials, there are also, and intentions to disclose, forms in which they are replaced by narrower terms (or appropriate grammatical variations thereof) such as “consisting_essentially_of,” “consisting_of,” or “consisting_of_only.” For example, when a subject is described as "comprises," it means that the subject also has more restrictive embodiments than "essentially consisting of..." or "consisting of..." of the described elements, and these are intended to be disclosed. Examples of various features are given for illustrative purposes, but terms such as "example" and "for example" mean non-restrictive examples and should not be interpreted as limiting a particular feature to a specific example. When "at_least" is followed by a number (e.g., "at_least_one"), it means that number or more. "at_least_a_portion" means the entire subject or a part of it (less than the whole). Similarly, "at_least_a_part" means the entire subject or a part of it (less than the whole). A "portion" or "part" comprises a physically separated portion of the subject, whether or not it has undergone chemical, compositional, or structural changes or modifications, or whether or not it has been bonded to one or more other subjects.Furthermore, “portion” or “part” also includes chemical parts derived from the subject, such as when the subject is a chemical precursor, which may have a different chemical composition or structure from the subject and may exist in a composition, compound, molecule, or structure together with one or more components that were not originally part of the subject. “At least a majority” means the whole or a majority less than the whole. The weight-based average values ​​of the properties of an item (e.g., fibers, fiber-containing particles, or bulk products) as used herein are synonymous with the mass-based average values ​​of the properties of the item and are usually different from the number-based average values ​​resulting from differences in mass content between individual items or the volume-based average values ​​resulting from differences in density between individual items.

Claims

1. A method for manufacturing a bulk product comprising fiber-containing particles, wherein the reinforcing fibers are held within the particle structure by a binder, and the method is A manufacturing process, wherein the manufacturing process is (i) A step of preparing a plurality of aggregates, wherein the aggregates are formed by tumbling a treatment mixture comprising discontinuous reinforcing fibers and a binder material, the aggregates comprising at least a portion of the discontinuous reinforcing fibers and at least a portion of the binder material, The particle length dimension is the maximum separation distance in the longitudinal direction between the first longitudinal end and the second longitudinal end of the aggregate, In a direction transverse to the longitudinal direction, the maximum particle width dimension at the longitudinal position between the first longitudinal end and the second longitudinal end, The aspect ratio is the value obtained by dividing the particle length dimension by the maximum particle width dimension, A step of preparing the aggregate having the particle structure comprising, (ii) A step of preparing a plurality of aggregate fractions by subjecting a plurality of aggregates to size classification, wherein the plurality of aggregate fractions comprises at least a first aggregate fraction having a first weight-average particle length dimension and a second aggregate fraction having a second weight-average particle length dimension, wherein the first weight-average particle length dimension is smaller than the second weight-average particle length dimension. (iii) A step of providing fiber-containing particles having the particle structure to be incorporated into the bulk product by processing at least a portion of the aggregates of the first aggregate fraction, The manufacturing process comprises, and A reprocessing step of reprocessing at least a portion of the discontinuous reinforcing fibers and the binder material of the second aggregate fraction, wherein the reprocessing step is (a) A step of preparing reprocessed discontinuous reinforced fibers by subjecting at least a portion of the aggregates in the second aggregate fraction to a length reduction treatment, thereby reducing the length of at least a portion of the discontinuous reinforced fibers in the second aggregate fraction, (b) A step of subjecting the manufacturing process at the time the reprocessing step occurs to at least a portion of the reprocessed discontinuous reinforced fibers from the second aggregate fraction and at least a portion of the binder material from the second aggregate fraction in the processing mixture of the manufacturing process at the time the reprocessing step occurs, The reprocessing step comprises, A method that includes [the following features].

2. The second weight-average particle length dimension is at least 1.25 times the first weight-average particle length dimension, The second weight-average particle length dimension is at most 10 times the first weight-average particle length dimension. The method according to claim 1.

3. The aforementioned first weight-average particle length dimension is in the range of 3 mm to 40 mm. The method according to claim 1 or 2.

4. The first aggregate fraction has a first weight-average aspect ratio, The second aggregate fraction has a second weight-average aspect ratio, The second weight-average aspect ratio is at least 1.25 times the first weight-average aspect ratio, The second weight-average aspect ratio is at most 10 times the first weight-average aspect ratio. The method according to any one of claims 1 to 3.

5. The processing mixture of the manufacturing process at the time of the reprocessing step is The weight ratio of the binder material to the reprocessed discontinuous reinforcing fibers is in the range of 0.9 to 1.1 times the weight ratio of the binder material to the discontinuous reinforcing fibers in the second aggregate fraction. The method according to any one of claims 1 to 4.

6. The processing mixture of the manufacturing process at the time of the reprocessing step is The reprocessed discontinuous reinforcing fibers in an amount equivalent to at least 90% by mass of the mass of the discontinuous reinforcing fibers in the second aggregate fraction, The binder material in an amount equivalent to at least 90% by mass of the mass of the binder material in the second aggregate fraction, It is equipped with The method according to any one of claims 1 to 5.

7. The processing mixture of the manufacturing process comprises the discontinuous reinforcing fibers and the binder material, in addition to water, in order to prepare the aggregates which are derived from the processing mixture. The processing mixture of the manufacturing process at the time of the reprocessing step comprises water derived from the second aggregate fraction. At least a portion of the second aggregate fraction subjected to the length reduction treatment contains water at a concentration of 5 to 50% by weight. The method according to any one of claims 1 to 6.

8. The processing mixture of the manufacturing process at the time of the reprocessing step comprises water derived solely from the second aggregate fraction. The method according to claim 7.

9. The processing mixture of the manufacturing process at the time of the reprocessing step comprises additional water in addition to the water derived from the second aggregate fraction. The method according to claim 7.

10. At the time of the reprocessing step, the discontinuous reinforcing fibers in the processing mixture of the manufacturing process consist only of the reprocessed discontinuous reinforcing fibers prepared from at least a portion of the second aggregate fraction. The method according to any one of claims 1 to 9.

11. The binder material in the processing mixture of the manufacturing process at the time of the reprocessing step comprises only the binder material from at least a portion of the second aggregate fraction. The method according to any one of claims 1 to 10.

12. The discontinuous reinforcing fibers in the processing mixture of the manufacturing process at the time of the reprocessing step include discontinuous reinforcing fibers other than the reprocessed discontinuous reinforcing fibers prepared from at least a portion of the second aggregate fraction. The method according to any one of claims 1 to 9.

13. The discontinuous reinforced fibers other than the reprocessed discontinuous reinforced fibers include the discontinuous reinforced fibers that are used in the manufacturing process at the time the reprocessing step occurs, as a discontinuous fiber supply in a dry form. The method according to claim 12.

14. The method further comprises a step of subjecting at least a portion of the discontinuous reinforcing fibers and binder material of the second aggregate fraction prepared during the manufacturing process to further reprocessing at the time the reprocessing step occurs. The method according to any one of claims 1 to 13.

15. Each of the aggregate fractions comprises a third aggregate fraction having a third weight-average particle length dimension. The third weight-average particle length dimension is greater than the first weight-average particle length dimension and less than the second weight-average particle length dimension. The method according to any one of claims 1 to 14.

16. The method further comprises a step of subjecting at least a portion of the third aggregate fraction to reprocessing. The method according to claim 15.

17. The method further comprises an initial manufacturing process in which at least a portion of the discontinuous reinforcing fibers for the processing mixture is supplied to the initial manufacturing process as a discontinuous fiber feed in a dry form. The method further comprises pretreatment of the reinforcing fibers for preparing the discontinuous fiber feed, The method according to any one of claims 1 to 16.

18. The aforementioned preliminary treatment is A step of preparing a plurality of fiber fractions comprising at least a first fiber fraction and a second fiber fraction by size classifying the mixture of the discontinuous reinforced fibers, wherein the first fiber fraction has a first weight-average fiber length, the second fiber fraction has a second weight-average fiber length, and the second weight-average fiber length is longer than the first weight-average fiber length, A step of preparing the discontinuous fiber supply such that it comprises at least a portion of the discontinuous reinforcing fibers of the first fiber fraction, It is equipped with The method according to claim 17.

19. The second weight-average fiber length is at least 1.25 times the first weight-average fiber length, The second weight-average fiber length is at most 10 times the first weight-average fiber length. The method according to claim 18.

20. The first weight-average fiber length is at least 1 mm, The aforementioned first weight-average fiber length is 18 mm or less. The method according to claim 18 or 19.

21. Each of the aforementioned fiber fractions comprises a third fiber fraction having a third weight-average fiber length. The third weight-average fiber length is shorter than the first weight-average fiber length. The method according to any one of claims 18 to 20.

22. The method further comprises the step of removing at least a portion of the third fiber fraction from the discontinuous fiber feed and the aggregate. The method according to claim 21.

23. At least a portion of the first fiber fraction forms at least a portion of the discontinuous fiber feed before being included in the discontinuous fiber feed without fiber modification after size classification. The method according to any one of claims 18 to 22.

24. The above method further, A step of preparing reduced-length fibers by subjecting at least a portion of the second fiber fraction to a fiber length reduction treatment, A step of preparing the discontinuous fiber supply so that it comprises at least a portion of the reduced-length fibers, It is equipped with The method according to any one of claims 18 to 23.

25. The method further comprises the step of recycling at least a portion of the reduced-length fibers to include at least a portion of the reduced-length fibers in the mixture of discontinuous reinforcing fibers subjected to size classification. The method according to claim 24.

26. The aforementioned preliminary treatment is A step of preparing an aligned fiber supply by increasing the longitudinal alignment of the reinforcing fibers relative to each other, A step of preparing the discontinuous fiber supply so that it comprises at least a portion of the reinforcing fibers of the aligned fiber supply, It is equipped with The method according to claim 17.

27. The step of preparing the discontinuous fiber supply includes a step of reducing the weight-average fiber length of the reinforcing fibers before increasing the longitudinal alignment of the reinforcing fibers by subjecting the reinforcing fibers to an upstream length reduction process as an upstream length reduction process. The method according to claim 26.

28. The step of preparing the discontinuous fiber supply includes a step of reducing the weight-average fiber length of the reinforcing fibers by subjecting the reinforcing fibers in the aligned fiber supply to a downstream length reduction process. The method according to claim 26 or 27.

29. The step of preparing the discontinuous fiber supply is as follows: A step of preparing a plurality of fiber fractions comprising at least a first fiber fraction and a second fiber fraction by size classifying the mixture of discontinuous reinforced fibers obtained from the downstream length reduction process, wherein the first fiber fraction has a first weight-average fiber length, the second fiber fraction has a second weight-average fiber length, and the second weight-average fiber length is longer than the first weight-average fiber length, A step of preparing the discontinuous fiber supply so that it comprises at least a portion of the first fiber fraction, It is equipped with The method according to claim 28.

30. The increase in the longitudinal alignment of the reinforcing fibers increases the longitudinal alignment of the reinforcing fibers with respect to the mechanical conveying direction when the reinforcing fibers are conveyed toward the downstream length reduction process. The method according to claim 28 or 29.

31. The increase in the longitudinal alignment of the reinforcing fibers comprises a step of transitioning the longitudinal alignment of the reinforcing fibers from a first alignment state to a second alignment state. In the second alignment state, the reinforcing fibers are further aligned in the direction of mechanical transport of the reinforcing fibers. In the first alignment state, at least 30% of the reinforcing fibers are oriented in the longitudinal direction at an alignment angle of 45° to 90° with respect to the machine transport direction. In the second alignment state, the reinforcing fibers, which are 20% or less in length, are oriented in the longitudinal direction at the alignment angle of 45° to 90° with respect to the machine transport direction. The method according to any one of claims 26 to 30.

32. The step of preparing the discontinuous fiber supply is performed after the increase in longitudinal alignment, A step of preparing a plurality of fiber fractions comprising at least a first fiber fraction and a second fiber fraction by size classifying the reinforcing fiber, wherein the first fiber fraction has a first weight-average fiber length, the second fiber fraction has a second weight-average fiber length, and the second weight-average fiber length is longer than the first weight-average fiber length, A step of preparing the discontinuous fiber supply so that it comprises at least a portion of the first fiber fraction, It is equipped with The method according to any one of claims 26 to 31.

33. The preliminary fiber supply for the aforementioned preliminary treatment comprises recycled reinforced fibers recovered from the composite material. The method according to any one of claims 17 to 32.

34. The aforementioned tumbling process includes rotary tumbling. The step of preparing the aggregate comprises the step of placing the reinforcing fibers and the binder material in a processing container, The rotary tumbling includes the step of rotating the processing container containing the reinforcing fibers and the binder material. The method according to any one of claims 1 to 33.

35. The preparation of the aggregate is A step of forming the aggregate as particles having the particle structure during tumbling, wherein the particle structure is The particle length dimension is the maximum separation distance between the first longitudinal end and the second longitudinal end of the particle in the longitudinal direction, At a position between the first longitudinal end and the second longitudinal end in the longitudinal direction, the maximum particle width dimension crossing the longitudinal direction, and The aspect ratio is the value obtained by dividing the particle length dimension by the maximum particle width dimension, The process of forming the aggregate, comprising: A step of recovering a batch of aggregates, wherein at least a portion of the aggregates is included as particles in the batch. It is equipped with, The method further comprises the step of processing at least a portion of the batch of aggregates to prepare a batch of bulk products comprising a plurality of fiber-containing particles having the particle structure. The method according to any one of claims 1 to 34.

36. In either or both of the batch of aggregates and the batch of bulk products, At least 25% by weight of the particles in the batch are A first tapered part that tapers in the longitudinal direction from the longitudinal position toward the first longitudinal end, A second tapered end that tapers in the longitudinal direction from the longitudinal position toward the second longitudinal end, It has a dual tapered shape, The method according to claim 35.

37. Each of the batch of aggregates and the batch of bulk product is, The weight-averaged particle length dimension is the weight-averaged particle length dimension of the particles in the batch, The weight-average aspect ratio is the weight average of the aspect ratios of the particles in the batch, It is equipped with, In either or both of the batch of aggregates and the batch of bulk products, The aforementioned weight-average particle length dimension is in the range of 3 mm to 40 mm. The aforementioned weight-average aspect ratio is within the range of 1.5 to 6. The method according to claim 36.

38. The reinforcing fiber is carbon fiber. The method according to any one of claims 1 to 37.

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