Apparatus for forming a substrate

Abstract

Methods and apparatuses for producing a substrate are described. A method and apparatus for introducing a component into a fluid supply are also presented. The method can include providing a first fluid supply. In some embodiments, the fluid supply can be configured as a foam. The method can also include providing a component feed system and a supply of the component. In some aspects, the method can include introducing the component into the fluid supply in an eductor. The resulting slurry comprising the fluid supply and the component can be transferred through a headbox. The resulting slurry can be dewatered to provide a substrate comprising the component.

Description

Technical Field

[0001] This disclosure relates to methods and apparatus for forming substrates. More specifically, this disclosure relates to foam forming methods and apparatus for forming substrates. Background Technology

[0002] Personal care products, such as diapers, disposable diapers, training pants, adult incontinence products, and feminine hygiene products, can include a variety of substrates. For example, diapers can include absorbent structures, nonwoven materials, and membranes. Similarly, facial tissues, wipes, and towels can also include a variety of substrates. Some of these substrates can include natural and / or synthetic fibers. In some products, some substrates may also include different types of components to provide additional functionality to the substrate and / or the final product itself.

[0003] For example, one such component that might be desired to be added to a substrate includes superabsorbent materials (SAM). SAM can be constructed in granular or fibrous form and is commonly used in substrates to increase absorbency. Personal care absorbent products such as diapers typically include SAM in their absorbency systems. Processes exist for forming substrates with SAM, involving the use of a forming chamber to mix SAM particles or fibers with cellulose fibers to form an absorbent core. These processes are typically performed in a dry environment because SAM is difficult to process when wet due to volume increase caused by absorbent fluids and gelation, as well as other potential drawbacks. However, alternative substrate forming processes can employ fluids, such as liquids, to produce the substrate, thereby providing a variety of additional properties and efficiencies in the manufacture and performance of such substrates.

[0004] Therefore, there is a need to develop methods and apparatus for introducing components into a fluid supply for forming a substrate. There is also a need to develop methods and apparatus for forming a substrate containing the components. Furthermore, there is a need to develop improved headboxes for forming substrates. Summary of the Invention

[0005] In one embodiment, an apparatus for forming a substrate is provided. The apparatus may include a first pump configured to pump a first fluid supply. The apparatus may also include a component feeding system. The component feeding system may include a component supply region for receiving the component supply and an outlet conduit. The apparatus may also include an ejector in fluid communication with the outlet conduit of the component feeding system and in fluid communication with a second fluid supply. At least one of the first fluid supply and the second fluid supply may comprise multiple fibers. The ejector may include a first discharge port. The apparatus may include a headbox in fluid communication with the first fluid supply and the first discharge port of the ejector. The apparatus may also include a forming surface configured to receive the resulting slurry transferred through the headbox.

[0006] In another embodiment, another apparatus for forming a substrate is provided. The apparatus may include a first pump configured to pump a first fluid supply. The apparatus may include a component feeding system. The component feeding system may include a component supply region for receiving the supply of components. The component feeding system may also include an outlet conduit including an outlet axis. The apparatus may include an ejector in fluid communication with the component supply and a second fluid supply via the outlet conduit of the component feeding system. The ejector may include a first discharge port. The apparatus may also include a mixing joint in fluid communication with the first discharge port of the ejector and with the first fluid supply. The mixing joint may include a second discharge port. The apparatus may include a headbox in fluid communication with the second discharge port of the mixing joint. The apparatus may also include a forming surface configured to receive the resulting slurry transferred through the headbox.

[0007] In yet another embodiment, a further apparatus for forming a substrate is provided. The apparatus may include a first pump configured to pump a first fluid supply. The apparatus may include a component feeding system. The component feeding system may include a component supply region for receiving the supply of components. The component feeding system may also include an outlet conduit including an outlet conduit axis. The apparatus may also include an ejector in fluid communication with the outlet conduit of the component feeding system and in fluid communication with the first fluid supply. The ejector may include a discharge port. The apparatus may include a headbox in fluid communication with the discharge port of the ejector. The apparatus may also include a forming surface configured to receive the resulting slurry transferred through the headbox. Attached Figure Description

[0008] The complete and practicable disclosure of the invention, presented to those skilled in the art, is set forth in more detail in the remainder of the specification with reference to the accompanying drawings, in which:

[0009] Figure 1 This is a process schematic diagram of an exemplary method for introducing a component into a fluid supply and forming a substrate containing the component, according to one embodiment of the present disclosure.

[0010] Figure 2 Is it like this? Figure 1 The process diagram shows a detailed schematic of the component feed system upstream of the headbox, two mixing joints, and two fluid supplies.

[0011] Figure 3 yes Figure 2 The cross-section of the first mixing joint and outlet conduit of the component feeding system.

[0012] Figure 4A This is a process schematic diagram of an alternative exemplary method for introducing a component into a fluid supply and forming a substrate containing the component, according to another embodiment of this disclosure.

[0013] Figure 4B This is a process schematic diagram of another alternative exemplary method for introducing a component into a fluid supply and forming a substrate containing the component, according to another embodiment of this disclosure.

[0014] Figure 4C This is a process schematic diagram of another alternative exemplary method for introducing a component into a fluid supply and forming a substrate containing the component, according to another embodiment of this disclosure.

[0015] Figure 5 This is a front top perspective view of an exemplary headbox, with the top surface removed for clarity.

[0016] Figure 6 yes Figure 5 Top view of the headbox.

[0017] Figure 7 yes Figure 5 Rear view of the headbox.

[0018] Figure 8 It is along Figure 6 The top surface is shown in the side-view perspective section taken from line 8-8.

[0019] Figure 9 It is along Figure 6 The side sectional view taken by line 8-8 shows the top surface.

[0020] The repeated use of reference numerals in this specification and drawings is intended to indicate the same or similar features or elements of this disclosure. Detailed Implementation

[0021] This disclosure relates to methods and apparatus for producing substrates comprising components. While this disclosure provides examples of substrates manufactured by foam molding, it is contemplated that the methods and apparatus described herein can be used to benefit wet web forming and / or air-laid web forming processes.

[0022] Each example is given illustratively and is not intended to be limiting. For example, a feature illustrated or described as part of one embodiment or drawing may be used in another embodiment or drawing to produce yet another embodiment. It is intended that this disclosure include such modifications and variations.

[0023] When describing elements of this disclosure or its preferred embodiments, the articles “a,” “an,” “the,” and “the” are intended to indicate the presence of one or more of that element. The words “comprising,” “including,” and “having” are intended to be inclusive, meaning that additional elements beyond those listed may be present. As used herein, the terms “first,” “second,” “third,” etc., do not specify a particular order but are used as a means of distinguishing different events when referring to the various features of this disclosure. Many modifications and variations may be made to this disclosure without departing from its spirit and scope. Therefore, the exemplary embodiments described herein should not be construed as limiting the scope of the invention.

[0024] definition

[0025] As used herein, the term "foam-formed product" means a product formed from a suspension of a mixture comprising solids, liquids and dispersed air bubbles.

[0026] As used herein, the term "foam-forming process" refers to a process used to manufacture products involving suspensions of mixtures comprising solids, liquids, and dispersed bubbles.

[0027] As used herein, the term "foaming fluid" means any one or more known fluids that are compatible with other components in the foam forming process. Suitable foaming fluids include, but are not limited to, water.

[0028] As used in this article, the term "foam half-life" refers to the time elapsed until half of the initial foaming material has reverted to liquid water.

[0029] As used herein, the term "layer" refers to a structure that provides a substrate region in the z-direction of a substrate composed of similar components and structures.

[0030] As used herein, the term “nonwoven web” refers to a web having a structure of individual fibers or threads that are layered but not in an identifiable manner (as in knitted webs).

[0031] As used herein, unless otherwise expressly indicated, when used in relation to the composition of materials, the terms “percentage,” “%,” “weight percentage” or “weight %” each refer to the amount of a component as a percentage of the total amount by weight, unless otherwise expressly indicated.

[0032] The term "personal care absorbent articles" as used herein refers to articles intended or adapted to be placed close to or near the wearer's body (i.e., adjacent to the body) to absorb and contain various liquid, solid, and semi-solid excretions from the body. Examples include, but are not limited to, diapers, diaper pants, training pants, youth pants, swim trunks, feminine hygiene products (including but not limited to menstrual pads or pants), incontinence products, medical clothing, surgical pads, and bandages, etc.

[0033] The term "layer" refers to a discontinuous layer in a multi-layer product, where individual layers can be arranged side by side.

[0034] The terms “twisting,” “bonding,” or “joining” in this context refer to the joining, adhesion, connection, or attachment of two elements. When they are joined, adhered, connected, or attached to each other directly or indirectly, such as when each is directly bonded to an intermediate element, the two elements are considered twisted, bonded, or joined together. The twisting, bonding, or joining of one element to another can be achieved through continuous or intermittent bonding.

[0035] As used herein, the term "superabsorbent material" refers to a water-swellable, water-insoluble organic or inorganic material, including superabsorbent polymers and compositions thereof that, under most favorable conditions, are capable of absorbing at least about 10 times, at least about 15 times, or at least about 25 times their own weight in an aqueous solution containing 0.9% by weight of sodium chloride.

[0036] Methods and equipment

[0037] In one embodiment, this disclosure relates to a method and apparatus 10 for forming a substrate 12. Figure 1A schematic diagram of an exemplary apparatus 10 is provided, which can be used as part of a foam forming process to manufacture a substrate 12 as a foam-forming product. The apparatus 10 may include a first tank 14 configured to maintain a first fluid supply 16. In some embodiments, the first fluid supply 16 may be foam. The first fluid supply 16 may include fluid supplied by a supply of fluid 18. In some embodiments, the first fluid supply 16 may include multiple fibers supplied by a supply of fiber 20; however, in other embodiments, the first fluid supply 16 may not contain multiple fibers. The first fluid supply 16 may also include a surfactant supplied by a supply of surfactant 22. In some embodiments, the first tank 14 may include a mixer 24, as will be discussed in more detail below. The mixer 24 may mix (e.g., agitate) the first fluid supply 16 to mix the fluid, fibers (if present), and surfactant with air or some other gas to generate foam. The mixer 24 may also mix the foam with fibers (if present) to generate a foam suspension of fibers, wherein the foam holds and separates the fibers to promote fiber distribution within the foam (e.g., as an artificial product of the mixing process in the first tank 14). Uniform fiber distribution can promote the desired substrate 12, including, for example, visual appearance of strength and quality.

[0038] The device 10 may also include a second tank 26 configured to maintain a second fluid supply 28. In some embodiments, the second fluid supply 28 may be foam. The second fluid supply 28 may include a fluid supplied by the supply of fluid 30 and a surfactant supplied by the supply of surfactant 32. In some embodiments, the second fluid supply 28 may contain multiple fibers in addition to or as an alternative to the fibers present in the first fluid supply 16. In some embodiments, the second tank 26 may include a mixer 34. The mixer 34 may mix the second fluid supply 28 to mix the fluid and surfactant with air or some other gas to generate foam.

[0039] For either or both of the first can 14 and the second can 26, the first fluid supply 16 or the second fluid supply 28 may be acted to form foam. In some embodiments, the foaming fluid and other components are acted to form a porous foam with an air content greater than about 50% by volume and ideally greater than about 60% by volume. In some aspects, highly inflated foam is formed having an air content between about 60% and about 95%, and in other aspects, between about 65% and about 85%. In some embodiments, the foam may be acted to introduce foam such that the expansion ratio (the volume of air in the expanded stable foam compared to other components) is greater than 1:1, and in some embodiments, the air:other component ratio may be between about 1.1:1 and about 20:1, or between about 1.2:1 and about 15:1, or between about 1.5:1 and about 10:1, or even between about 2:1 and about 5:1.

[0040] Foam can be generated by one or more means known in the art. Examples of suitable methods include, but are not limited to, vigorous mechanical agitation by mixers 24, 34, injection of compressed air, etc. Mixing components by using a high-shear, high-speed mixer is particularly suitable for forming the desired highly porous foam. Various high-shear mixers are known in the art and are considered suitable for use in this disclosure. High-shear mixers typically use a tank to hold the foam precursor and / or one or more conduits through which the foam precursor is guided. High-shear mixers may use a series of screens and / or rotors to process the precursor and result in vigorous mixing of the components and air. In a particular embodiment, a first tank 14 and / or a second tank 26 are provided, having one or more rotors or impellers and an associated stator. The rotors or impellers rotate at high speed to induce flow and shear. For example, air may be introduced into the tank at various locations or simply drawn in by the action of mixers 24, 34. While the specific mixer design may affect the speed required to achieve the desired mixing and shearing, in some embodiments, a suitable rotor speed may be greater than about 500 rpm, and for example, between about 1000 rpm and about 6000 rpm, or between about 2000 rpm and about 4000 rpm. In some embodiments, mixers 24, 34 may be operated with the foam until the eddies in the foam disappear or a sufficient volume increase is achieved, relative to a rotor-based high-shear mixer.

[0041] Additionally, it should be noted that for the first tank 14 and / or the second tank 26, the foaming process can be completed in a single foam-generating step or in a series of foam-generating steps. For example, in one embodiment, all components of the first fluid supply 16 in the first tank 14 (e.g., the supply of fluid 18, fiber 20, and surfactant 22) can be mixed together to form a slurry from which foam is formed. Alternatively, one or more individual components can be added to the foaming fluid to form an initial mixture (e.g., a dispersion or foam), and then the remaining components can be added to the initially foamed slurry, after which all components come into play to form the final foam. In this regard, fluid 18 and surfactant 22 can begin mixing and come into play to form the initial foam before any solids are added. If desired, fibers can then be added to the water / surfactant foam, which then further comes into play to form the final foam. Alternatively, fluid 18 and fiber 20 (such as high-density cellulose pulp) can be vigorously mixed at a high consistency to form an initial dispersion, followed by the addition of foaming surfactants, additional water, and other components (such as synthetic fibers) to form a second mixture, which is then mixed and acts to form foam.

[0042] The foam density forming the foam in the first fluid supply 16 in the first tank 14 and / or the foam forming the second fluid supply 28 in the second tank 26 can vary depending on the specific application and various factors (e.g., the fiber raw material used). In some embodiments, for example, the foam density may be greater than about 100 g / L, such as greater than about 250 g / L, such as greater than about 300 g / L. The foam density is typically less than about 800 g / L, such as less than about 500 g / L, such as less than about 400 g / L, such as less than about 350 g / L. In some embodiments, for example, lower density foams with a typically lower density than about 350 g / L, such as less than about 340 g / L, such as less than about 330 g / L are used.

[0043] In some embodiments, the device 10 may further include a first pump 36 and a second pump 38. The first pump 36 may be in fluid communication with a first fluid supply 16 and may be configured to pump the first fluid supply 16 to transfer the first fluid supply 16. The second pump 38 may be in fluid communication with a second fluid supply 28 and may be configured to pump the second fluid supply 28 to transfer the second fluid supply 28. In some embodiments, the first pump 36 and / or the second pump 38 may be a screw pump or a centrifugal pump; however, other suitable types of pumps are contemplated for use. Additionally, as further discussed below, in some embodiments, the device may be provided with a single pump that can pump a single fluid supply to both the first fluid supply 16 and the second fluid supply 28.

[0044] like Figure 1 and Figure 2As depicted, the device 10 may also include a component feeding system 40. The component feeding system 40 may include a component supply area 42 for receiving a supply of component 44, such as... Figure 2 The portion of the component supply region 42 shown is cut off. The component feeding system 40 may also include an outlet conduit 46. The cross-sectional shape of the outlet conduit 46 may be circular or may be constructed in a rectangular manner, such as to form a slot. The component feeding system 40 may also include a hopper 48. The hopper 48 may be coupled to the component supply region 42 and may be used to refill the component supply region 42 with the supply of component 44.

[0045] In some embodiments, the component feeding system 40 may include a solid volumetric pump. Examples of solid volumetric pumps that may be used herein may include systems utilizing screws / augers, belts, vibratory trays, rotary discs, or other known systems for handling and discharging the supply of component 44. Other types of feeders may be used in the component feeding system 40, such as batching feeders, such as those manufactured by Christy Machine & Conveyor, Fremont, Ohio. In some embodiments, the component feeding system 40 may also be configured as a conveying system.

[0046] The component feeding system 40 may also include a fluid control system 50. The fluid control system 50 may be configured to control gas entrainment into the fluid supply, in which the supply of component 44 is placed. In some embodiments, the fluid control system 50 may include a housing 52. The housing 52 may form a pressurized, sealed volume around the component feeding system 40. In other embodiments, the fluid control system 50 may be formed as an integral part of the component feeding system 40 itself, so that a separate housing 52 around the component feeding system 40 is not required. Figure 1 and Figure 2 As depicted, in some embodiments, the fluid control system 50 may also include a discharge port 54.

[0047] The supply of component 44 may be in the form of microparticles and / or fibers. In one embodiment as described herein, the supply of component 44 may be in the form of superabsorbent material (SAM) in microparticle form. In some embodiments, SAM may be in the form of fibers. Of course, other types of components, as further described below, are also contemplated for use in the apparatus 10 and methods described herein. The component feed system 40 as described herein may be particularly advantageous for the supply of component 44, which is best suited to be kept in a dry environment with minimal contact with the fluids or foams used in the apparatus 10 and methods described herein.

[0048] refer to Figures 1 to 3In some embodiments, the device 10 and method described herein may include a first mixing connector 56 and a second mixing connector 58. In a preferred embodiment, the first mixing connector 56 may be an injector. The first mixing connector 56 may be in fluid communication with the outlet conduit 46 of the component feed system 40 and with a second fluid supply 28. Figure 3 As depicted, the first mixing connector 56 may include a first inlet 60 and a second inlet 62. The first inlet 60 may be in fluid communication with the supply fluid of component 44 via an outlet conduit 46. The second inlet 62 may be in fluid communication with the second fluid supply 28. The first mixing connector 56 may also include a discharge port 64.

[0049] In a preferred embodiment, the first mixing connector 56 may be configured as a coaxial injector. For example, in a preferred embodiment, the first mixing connector 56 may be configured such that the first inlet axis 66 of the first inlet 60 of the first mixing connector 56 is coaxial with the outlet axis 68 of the outlet conduit 46 supplying the component 44. The first mixing connector 56 may also be configured such that the outlet axis 70 of the outlet 64 is coaxial with the outlet axis 68 of the outlet conduit 46. Thus, the first mixing connector 56 may be configured such that the first inlet axis 66 of the first inlet 60 is coaxial with the outlet axis 70 of the outlet 64 of the first mixing connector 56. A second inlet 62 providing the second fluid supply 28 to the first mixing connector 56 may be configured to enter the first mixing connector 56 from one side of the first mixing connector 56. The configuration in which the supply of component 44 is delivered in the first inlet 60 in a manner coaxial with the discharge axis 70, rather than allowing the second fluid supply 28 to enter at the first inlet 60, is the opposite of most injector configurations that use the prime mover of the fluid supply to mix the fluid supply and components, but provides the advantages of the first mixing joint 56 as described herein.

[0050] When configured as an ejector, the first mixing connector 56 mixes the supply of component 44 from the component feed system 40 with the second fluid supply 28. The second fluid supply 28 provides a driving pressure to the supply of component 44 by diverting the second fluid supply 28 into and through the first mixing connector 56 at the second inlet 62. This driving pressure can create a vacuum on both the supply of component 44 and the component feed system 40 to facilitate the suction of the supply of component 44 for mixing and entrainment in the second fluid supply 28. In some embodiments, the driving pressure can create a vacuum of less than 1.5 in Hg on the supply of component 44; however, in other embodiments, the driving pressure can create a vacuum of 5 in Hg or greater, or 10 in Hg or greater, on the supply of component 44.

[0051] The fluid control system 50 can help manage the proper distribution and entrainment of component 44 supplied to the second fluid supply 28, and can help control fluid entrainment within the second fluid supply 28 downstream of the component feed system 40. For example, without the housing 52 surrounding the component feed system 40, additional fluid (e.g., ambient gas, such as air) could be entrained into the second fluid supply 28 when the supply of component 44 is metered into it. This can also happen when the second fluid supply 28 generates driving pressure on the component feed system 40, and a vacuum pull on the supply of component 44 could cause additional air to be entrained into the second fluid supply 28. In some cases, it may be desirable for additional air to be entrained in the second fluid supply 28; however, in other cases, it may be desirable to control the gas content of the second fluid supply 28 while supplying component 44 into the second fluid supply 28 at the first mixing joint 56. For example, in some cases where the second fluid supply 28 is foam, the gas content in the foam may be desired to remain relatively constant as the foam passes through the first mixing joint 56. Therefore, the fluid control system 50 can help control the pressure on the component feed system 40 and the airflow through the component feed system, in order to help prevent or at least control the amount of gas entrained in the second fluid supply 28 when the supply of component 44 is mixed with the second fluid supply 28, and can help counteract the supply of component 44 generated by the second fluid supply 28 and the driving pressure on the component feed system 40.

[0052] In some embodiments, the fluid control system 50 may include a sealed component feed system 40. For example, as discussed above, the fluid control system 50 may include a housing 52 to provide a seal on the component feed system 40. The sealed component feed system 40 may help prevent additional air entrainment in the second fluid supply 28 when the supply of component 44 is introduced into the second fluid supply 28 in the first mixing joint 56.

[0053] However, in some embodiments, it may be beneficial to include additional capabilities of the fluid control system 50. For example, in some embodiments, the fluid control system 50 may include a discharge orifice 54. The discharge orifice 54 may be configured to discharge fluid flows, such as atmospheric airflow, to provide additional fluid flow control over the component feed system 40. The discharge orifice 54 may discharge airflow (e.g., gas flow) within the housing 52 to help control airflow and pressure within the housing 52 surrounding the component feed system 40. It has been found that by providing a discharge orifice 54 to provide some of the atmospheric airflow to the component feed system 40, backflow of the second fluid supply 28 in the first mixing joint 56 can be reduced or eliminated. Reducing backflow of the second fluid supply 28 in the first mixing joint 56 can help prevent the component feed system 40 from becoming clogged or requiring cleaning, especially where the component feed system 40 may deliver dry particulate matter (such as SAM). Under other process conditions, a completely sealed component feed system 40 may be desirable for similar reasons.

[0054] Additionally or alternatively, the fluid control system 50 may be configured to provide additional airflow (e.g., airflow) and / or positive pressure to prevent backfilling of the component feed system 40 in some cases (e.g., if a blockage occurs downstream of the first mixing joint 56 in the device 10). In the event of a blockage causing increased pressure, the second fluid supply 28 may wish to backfill the component feed system 40. Backfilling fluid into the component feed system 40 can be detrimental to processing, particularly if the supply of component 44 is a dry component (such as SAM). A fluid control system 50 configured to provide positive pressure to the component feed system 40 can help prevent such backfilling of the component feed system 40.

[0055] It is also conceivable that other additional aspects of the fluid control system 50 may be used to maintain airflow and pressure at appropriate levels for the component feed system 40, including, but not limited to, supplying a vacuum to the component feed system 40 in addition to or in lieu of air intake at the discharge orifice 54 and / or the aforementioned positive pressure.

[0056] like Figure 3As depicted, in some embodiments, the first mixing connector 56 may further include a Venturi section 72. The Venturi section 72 can be a necking region of the first mixing connector 56, which can increase the velocity of the second fluid supply 28 through the Venturi section 72, and thus increase the vacuum pressure generated by the second fluid supply 28 on the supply of component 44 in the component feed system 40, and can help entrain the supply of component 44 within the second fluid supply 28. In some embodiments, the distal end 74 of the outlet conduit 46 supplying component 44 to the first mixing connector 56 may be disposed in the Venturi section 72. The position of the distal end 74 of the outlet conduit 46 can be adjusted within the Venturi section 72 as a means of controlling the pressure of the second fluid supply 28 as it discharges from the first mixing connector 56 and the pressure of the component feed system 40.

[0057] Compared to when the second fluid supply 28 enters the first mixing contact 56, the first mixing contact 56 also provides pressure control over the transfer of the second fluid supply containing component 44 when the second fluid supply 28 exits the discharge port 64 of the first mixing contact 56. The second fluid supply 28 can be transferred at a second fluid pressure before the first mixing contact 56. The second fluid supply 28 containing the component from the supply of component 44 can exit the discharge port 64 of the first mixing contact 56 at a discharge pressure. The pressure difference between the second fluid pressure before the first mixing contact 56 and the discharge pressure can be controlled. In some embodiments, this pressure difference can be controlled by changing the flow rate of the second fluid supply 28. In some embodiments, this pressure difference can be controlled by the position of the distal end 74 of the outlet conduit 46 in the Venturi section 72 of the first mixing contact 56. For example, if the distal end 74 of the outlet conduit 46 moves further into the Venturi section 72, the area through which the second fluid supply 28 flows through the Venturi section 72 decreases, and therefore the supply pressure of the second fluid supply 28 increases. If the distal end 74 of the outlet conduit 46 is further removed from the Venturi section 72 (i.e., rearward toward the component feed system 40), the area through which the second fluid supply 28 flows through the Venturi section 72 increases, and consequently the supply pressure of the second fluid supply 28 entering the first mixing connector 56 decreases, and the vacuum level on the component feed system 40 also decreases. In some embodiments, the pressure difference between the second fluid pressure and the discharge pressure before the first mixing connector 56 is preferably controlled to be less than or equal to 25 pounds per square inch (psi), or more preferably less than 20 psi, or less than 15 psi, or less than 10 psi, or less than 5 psi.

[0058] Another feature of the first mixing connector 56 may be that a second inlet 62 providing the second fluid supply 28 is located upstream of the distal end 74 of the outlet conduit 46, which supplies component 44 from the component feed system 40 to the first mixing connector 56. This first mixing connector can generate enhanced mixing and transfer of the component 44 supply to the second fluid supply 28 within the first mixing connector 56. With this configuration, the second fluid supply 28 can enter the first mixing connector 56 upstream of the component 44 supply, preventing any supply of component 44 from engaging or adhering to the inner surface of the first mixing connector 56. Therefore, in Figure 3 In the embodiment depicted, the coaxiality of the outlet axis 68 of the outlet conduit 46 with the discharge axis 70 of the first mixing connector 56 and the upstream inlet of the second fluid supply 28 into the first mixing connector 56 can create an annular fluid protection around the inlet of the component supply when the component 44 is entrained in the second fluid supply 28 in the first mixing connector 56.

[0059] It should be noted that, although in Figures 1 to 3 The diagram shows a single outlet conduit 46 and a single first mixing connector 56 for the component feed system 40, but it is conceivable that the outlet conduit 46 could be split into two or more conduits to feed to two or more first mixing connectors 56 for mixing the supply of component 44 with the second fluid supply 28. In this configuration, the second fluid supply 28 may include as many conduits as the first mixing connectors 56. By having more than one outlet conduit 46 and more than one first mixing connector 56 to mix the supply of component 44 with the second fluid supply 28, a larger flow rate of the second fluid supply 28 containing the component from the supply of component 44 can be achieved.

[0060] In some embodiments, it is also conceivable that the first mixing joint 56 may be an injector with a different configuration than the coaxial injector described above. For example, it is conceivable that the first mixing joint 56 may be an injector shaped as a slot injector.

[0061] Return to reference Figure 1In some embodiments, device 10 may include a second mixing connector 58. The second mixing connector 58 provides the function of mixing a second fluid supply 28 containing components supplied from component 44 with a first fluid supply 16. The second fluid supply 28, containing components supplied from component 44, can be transferred to the second mixing connector 58 as it exits the outlet 64 of the first mixing connector 56. The first fluid supply 16 can be delivered to the second mixing connector 58 via a first pump 36. The second mixing connector 58 can mix the first fluid supply 16 and any of its components (e.g., fluid 18, fiber 20, surfactant 22) with the second fluid supply 28 and any of its components (e.g., fluid 30, surfactant 32) and components supplied from component 44 to provide a resulting slurry 76. The resulting slurry 76 can be transferred from the second mixing connector 58 through the outlet 78 of the second mixing connector 58 to a headbox 80. In some embodiments, a gap may exist between the outlet 78 of the second mixing connector 58 and the headbox 80, such as... Figure 3 As shown. However, in other embodiments, the discharge port 78 of the second mixing connector 58 may be integrated with the headbox 80.

[0062] exist Figure 4A Alternative embodiments of the apparatus 110 and method for forming substrate 12 are depicted. Unless otherwise stated, 4A has the same Figures 1 to 3 The device 10 and method described herein have the same components. Figure 4A The equipment 110 includes only a first tank 14 for containing the first fluid supply 16. Figure 4A The apparatus 110 and method do not include a second tank 26 having a second fluid supply 28. The first fluid supply 16 may include the supply of fluid 18, the supply of fiber 20, and the supply of surfactant 22. The apparatus 110 may also include as referenced above. Figures 1 to 3 The component feeding system 40, fluid control system 50, and mixing connector 56 are described. Based on this configuration, the first pump 36 can transfer the first fluid supply 16 to the first mixing connector 56. As previously described, the component feeding system 40 can transfer the supply of component 44 to the first mixing connector 56. In a preferred embodiment, the first mixing connector 56 can be an injector, and more preferably a reference... Figure 3The coaxial injector is described above. A first mixing connector 56 mixes the first fluid supply 16 with the components supplied from component 44 and provides the resulting slurry 76 exiting through an outlet 64 of the first mixing connector 56 and transferring it to a headbox 80. In some embodiments, the outlet 64 of the first mixing connector 56 may be separate from the headbox 80; however, in some embodiments, the outlet 64 of the first mixing connector 56 may be integrated with the headbox 80. In some embodiments, the first fluid supply 16 may include fluid 18 and surfactant 22, which will be mixed with the supply of component 44 to provide the resulting slurry 76, but without any fibers. In other embodiments, the first fluid supply 16 may include fluid 18, fibers 20, and surfactant 22, which will be mixed with the supply of component 44 to provide the resulting slurry 76.

[0063] exist Figure 4B Another alternative embodiment of the apparatus 210 and method for forming substrate 12 is depicted. Apparatus 10 may include a first pump 36 in fluid communication with a first fluid supply 16. The first fluid supply 16 may include a supply of fluid 18 and a supply of surfactant 22. The first fluid supply 16 may be separated at a joint 17. The first fluid supply 16 may continue through two control valves 23. The first fluid supply 16 may continue through one of the control signals 23 in conduit 19 and toward headbox 80. A supply of fiber 20 may be added to the first fluid supply 16 via control valve 23. Preferably, the supply of fiber 20 may be provided to the first fluid supply 16 in the form of a fluid supply (such as foam).

[0064] When the first fluid supply is split at connector 17, the first fluid supply 16 can be pumped through the second control valve 23 in conduit 21 toward the first mixing connector 56. The fluid supply in this conduit may be referred to as the second fluid supply 28. The second fluid supply 28 may include the supply of fluid 18 and the supply of surfactant 22 (i.e., from the first fluid supply 16). In some embodiments, such as Figure 4B As shown, the supply of fiber 20' can preferably be added to the second fluid supply 28. Preferably, the supply of fiber 20' can be provided to the first fluid supply 16 in the supply of fluid (such as foam).

[0065] exist Figure 4BIn the illustrated embodiment, the supply of component 44 can be added to the second fluid supply 28 at the first mixing connector 56 as described above. Device 210 may include an output 65 of the first mixing connector 56 containing component 44 downstream of the discharge port 64 of the first mixing connector 64. The fluid in the output 65 of the first mixing connector 56 and the supply of component 44 can provide a first input 67 to the headbox 80. A first fluid supply 16 can provide a second input 69 to the headbox 80. The first input 67 can be separated from the second input 69 entering the headbox 80. For example, in some embodiments, the first input 67 containing component 44 can be separated from the second input 69 by a z-direction isolation wall 71 (also referred to as a sheet), and thus the fluid supplies 16, 28 can be separated from each other for at least a portion of the headbox 80 when they are diverted through the headbox 80 to provide the resulting slurry 76. In doing so, the resulting slurry 76 can provide two distinct layers to provide a bilayer substrate 12.

[0066] exist Figure 4C Another alternative implementation is shown in the figure. Figure 4C Similar to Figure 2 The configuration shown, however, Figure 4C The configuration provides a discharge orifice 154 that provides a controlled fluid flow to the supply of component 44 after component 44 enters the outlet conduit 46 of the component feed system 40, but upstream of the first mixing joint 56. This configuration can supply fluid (e.g., liquid, gas, or foam) to the supply of component 44 to help control fluid entrainment within the second fluid supply 28 when the supply of component 44 mixes with the second fluid supply 28 in the first mixing joint 56. For example, in one embodiment, adding a foam flow to the discharge orifice 154 can help prevent additional gas (e.g., air) from being entrained in the supply of component 44 when it mixes with the second fluid supply 28.

[0067] Regardless of whether the apparatus 10, 110, 210 and method used for transferring the resulting slurry 76 are as described herein, or another apparatus and / or method, a headbox 80 may be provided to further transfer the resulting slurry 76 to form the substrate 12. Figures 5 to 9 As depicted, the headbox 80 may have a longitudinal direction 81 and a transverse direction 83. The longitudinal direction 81 is in the direction in which the resulting slurry 76 is transferred through the headbox 80. For clarity, Figures 5 to 9 The resulting slurry 76 is not shown in the figure.

[0068] The headbox 80 may include at least one flow section 82. Figures 5 to 9 In the embodiment of the headbox 80 depicted herein, the headbox 80 includes two flow sections 82. For example... Figure 5As shown, flow segments 82 may be spaced apart from each other in the transverse direction 83, but may be in the same overall plane defined by the longitudinal direction 81 and the transverse direction 83. It is contemplated that in some embodiments including more than one flow segment 82, the flow segments 82 may be arranged such that one flow segment 82 is positioned on top of another flow segment 82 in the z-direction 85 perpendicular to the plane defined by the longitudinal direction 81 and the transverse direction 83. In some embodiments including more than one flow segment 82, the two flow segments 82 may be configured to be substantially similar to each other. However, it is also contemplated that, depending on various factors, such as, but not limited to, the characteristics of the substrate 12 to be formed, one flow segment 82 may be configured differently from another flow segment 82. Additionally, although in Figures 5 to 9 The embodiment shows two flow sections 82, but it is contemplated that the headbox 80 may include three or more flow sections 82. The number of flow sections 82 can be adjusted to achieve various flow rates of the resulting slurry 76, the desired width of the substrate 12, and / or the number of z-direction layers of the substrate 12.

[0069] Each flow section 82 may include a bottom surface 84 and a top surface 86 (in... Figure 8 and Figure 9 (Marked in Chinese). For clarity, from... Figures 5 to 7 The top surface 86 is removed to outline the internal features of the headbox 80. The flow section 82 may also include a first side 87 and a second side 88. The second side 88 may be opposite the first side 87. In some embodiments, the first side 87 and the second side 88 may be configured to be symmetrical about each other about an axis parallel to the longitudinal direction 81. Figure 6 In the best depiction, the first side 87 and the second side 88 may each include first portions 87a, 88a protruding into the interior 89 of the flow section 82. The first side 87 and the second side 88 may also include second portions 87b, 88b recessed into the interior 89 of the flow section 82, respectively. In some embodiments, the first side 87 and the second side 88 may each include a radius of curvature varying along the length of the first portion 87a and the second portion 88b in the longitudinal direction 81. The first side 87 and the second side 88 may be configured such that each side 87, 88 includes a curved section 90. The curved section 90 may serve as a transition between the first portions 87a, 88a and the second portions 87b, 88b of the first side 87 and the second side 88, respectively. The curved section 90 may be a linear section or may be steeper, such as... Figure 5 and Figure 6 The curves are depicted in the figure (where the curved section 90 is represented by points for identification purposes).

[0070] The interior 89 may include the longitudinal side profile as viewed from the top view of the interior 89, such as Figure 6The portion depicted includes a first side profile 77 and a second side profile 79. As viewed from a top view of the interior 89, the first side profile 77 may be the profile of a first side 87, and the second side profile 79 may be the profile of a second side 88. The first side profile 77 and the second side profile 79 may each include first portions 87a and 88a protruding into the interior 89 of the flow section 82, and each may include second portions 87b and 88b recessed into the interior 89 of the flow section 82. For example, these side profiles 77 and 79 may be obtained regardless of the presence of the first side 87, the second side 88, the top surface 86, and the bottom surface 84, or whether these sides 87 and 88, as well as the top and bottom surfaces 86 and 84, are clearly demarcated, such as if the interior 89 of the flow section 82 is defined by smooth surfaces and curvature, such as in an elliptical cross-section.

[0071] The headbox 80 can be configured such that each flow section 82 includes an inlet 91. Each flow section 82 may also include an outlet 92. Figure 7 As shown in the rear view of the headbox 80, in some embodiments, the inlet 91 may have a circular cross-sectional shape, allowing it to connect to a circular cross-section conduit for transferring the resulting slurry 76 to the headbox 80. Of course, it is conceivable that the inlet 91 may have other cross-sectional shapes. Additionally, it is conceivable that the inlet 91 of the headbox 80 may form part of the discharge port 78 of the second mixing connector 58 or the first mixing connector 56 discussed above.

[0072] like Figure 6 As shown in the left flow section 82, the width W1 of the interior 89 at the inlet 91 may be smaller than the width W2 of the interior 89 at the outlet 92. For the purposes of this document, the widths W1 and W2 are defined as being measured in a direction parallel to the transverse 83 of the headbox 80 and in the plane defined by the longitudinal 81 and the transverse 83 between the first side 87 and the second side 88.

[0073] like Figure 9 As depicted herein, the interior 89 of the flow section 82 may include a height H1 at the inlet 91, which is greater than the height H2 of the interior 89 at the outlet 92. For purposes herein, heights H1 and H2 are defined as measured between the bottom surface 84 and the top surface 86 in a direction parallel to the z-direction 85, which is perpendicular to the plane defined by the longitudinal direction 81 and the transverse direction 83. Figure 9 The text also describes that the interior 89 of the flow section 82 is configured such that the top surface 86 and the bottom surface 84 provide a change in the flow path between the inlet 91 and the outlet 92 in the z direction 85.

[0074] In some embodiments, the first side 87 and the second side 88 of the flow section 82 may each include flow diffusion portions 87c and 88c. The flow diffusion portions 87c and 88c may be closer to the inlet 91 than the first portion 87a of the first side 87 and the first portion 88a of the second side 88, respectively. The first portions 87a and 88a of the first side 87 and the second side 88 may be closer to the inlet 91 than the second portions 87b and 88b of the first side 87 and the second side 88, respectively.

[0075] When the resulting slurry 76 enters the headbox 80 through each inlet 91, it first enters the interior 89 of the flow section 82 and the flow diffusion portions 87c and 88c of the first side 87 and the second side 88, respectively. Here, the width of the flow path of the resulting slurry 76 increases in the transverse direction 83. After passing through the flow diffusion portions 87c and 88c of the first side 87 and the second side 88, the resulting slurry 76 expands further in width as it is transferred through the first portions 87a and 88a of the first side 87 and the second side 88, respectively. Then, the flow of the resulting slurry 76 passes through the curved sections 90 on each side of the first side 87 and the second side 88, and finally through the second portions 87b and 88b of the first side 87 and the second side 88, respectively. Importantly, this controlled expansion of the flow width of the resulting slurry 76, and the combination of the first portions 87a, 88a and the second portions 87b, 88b of the first side 87 and the second side 88, respectively, provides improved flow through the interior 89 of the flow section 82, which reduces vortex or other turbulent characteristics of the resulting slurry 76 as it passes through the headbox 80. Therefore, the side profiles 77, 79 (e.g., the first side 87 and the second side 88) of the interior 89 of the flow section 89 produce a configuration that favors minimizing the time the resulting slurry 76 spends in the headbox 80 while expanding to the desired width and height for forming the substrate 12. This can be a significant processing advantage where the component supplied from component 44 is a dry article (e.g., SAM), for which it is desirable to minimize the time exposed to the liquid that forms a portion of the resulting slurry 76.

[0076] Furthermore, the varying height and width configuration of the interior 89 of the flow section 82 is intended to contribute to enhanced flow consistency of the resulting slurry 76 passing through the headbox 80. As described above, the width W1 of the interior 89 at the inlet 91 is smaller than the width W2 of the interior 89 at the outlet 92 to allow the resulting slurry 76 to disperse across the substrate 12 to the desired width in the transverse direction 83. As the width of the interior 89 increases as the resulting slurry 76 passes through the headbox 80, the height of the interior 89 decreases. As mentioned above, the height H1 of the interior 89 at the inlet 91 is greater than the height H2 of the interior 89 at the outlet 92 of the flow section 82. By reducing the height of the interior 89 as the width increases 89, the flow of the resulting slurry 76 through the interior 89 of the headbox 80 is maintained in a more stratified manner. Again, this helps to reduce the time the resulting slurry 76 spends in the headbox 80, which, as mentioned above, can be advantageous when the resulting slurry 76 contains components from the supply of component 44 for drying articles such as SAM, as it is desirable to minimize the exposure time of the liquid.

[0077] It is also worth noting that the arcuate shape of the z-direction 85 between the top surface 86 and the bottom surface 84, between the inlet 91 and the outlet 92, is believed to provide enhanced control over the flow of the resulting slurry 76 and may help reduce eddies or other vibrations in the flow of the resulting slurry 76 through the headbox 80, which further enhances the advantages noted above with reference to the components supplied from component 44. For example, this arcuate shape is believed to provide a more consistent basis weight and fiber orientation in the transverse direction 83 in the formed substrate 12, particularly when used in foam forming processes.

[0078] Return to reference Figure 1As shown in Figure 4, devices 10, 110, and 210 may further include a forming surface 94 on which the resulting slurry 76 is deposited after exiting the outlet 92 of the headbox 80. The forming surface 94 may be a porous sheet, such as a woven tape or screen, or any other suitable surface for receiving the resulting slurry 76. In some embodiments, the resulting slurry 76 may be deposited onto another pre-formed substrate that may be located on top of the forming surface 94. Devices 10 and 110 may further include a dewatering system 96 configured to remove liquid from the resulting slurry 76 on the forming surface 94. In some embodiments, the dewatering system 96 may be configured to provide a vacuum to the resulting slurry 76 to draw liquid from it, and in doing so, the resulting slurry 76, comprising multiple fibers 20 and component 44, may be transformed into substrate 12. In some embodiments, devices 10, 110, and 210 may further include a drying system 98. The drying system 98 may be configured to further dry the resulting slurry 76 and / or substrate 12. In some embodiments, devices 10, 110, 210 may include a winding system 99 configured to wind substrate 12 in a roller manner. In other embodiments, devices 10, 110, 210 may be used in any other suitable configuration to decorate or collect substrate 12.

[0079] foamed fluid

[0080] The foam forming process described herein may include a foaming fluid. In some embodiments, the foaming fluid may comprise between about 85% and about 99.99% of the foam (by weight). In some embodiments, the foaming fluid used to produce the foam may comprise at least about 85% of the foam (by weight). In some embodiments, the foaming fluid may comprise between about 90% and about 99.9% of the foam (by weight). In some other embodiments, the foaming fluid may comprise between about 93% and 99.5% of the foam, or even between about 95% and about 99.0% of the foam (by weight). In a preferred embodiment, the foaming fluid may be water; however, other processes are contemplated that may utilize other foaming fluids.

[0081] foaming surfactants

[0082] The foam forming process described herein can utilize one or more surfactants. The fibers and surfactants, together with the foaming liquid and any additional components, can form a stable dispersion that can maintain a substantially high porosity for a longer period than a drying process. In this regard, the surfactant is selected to provide a foam with a foam half-life of at least 2 minutes, more preferably at least 5 minutes, and most preferably at least 10 minutes. The foam half-life can be a function of surfactant type, surfactant concentration, foam component / solids level, and mixing capacity / air content in the foam. The foaming surfactant used in the foam can be selected from one or more foaming surfactants known in the art that can provide the desired level of foam stability. In this regard, the foaming surfactant can be selected from anionic, cationic, nonionic, and amphoteric surfactants, provided that they, alone or in combination with other components, provide the necessary foam stability or foam half-life. It should be understood that more than one surfactant can be used, including surfactants of different types (provided they are compatible) and more than one surfactant of the same type. For example, combinations of cationic and nonionic surfactants or combinations of anionic and nonionic surfactants can be used in some embodiments due to their compatibility. However, in some implementations, the combination of cationic and anionic surfactants may not be satisfactory due to incompatibility between the surfactants.

[0083] Anionic surfactants considered suitable for use in this disclosure include, but are not limited to, anionic sulfate surfactants, alkyl ether sulfonates, alkyl aryl sulfonates, or mixtures or combinations thereof. Examples of alkyl aryl sulfonates include, but are not limited to, alkylbenzene sulfonic acids and their salts, dialkylbenzene disulfonic acids and their salts, dialkylbenzene sulfonic acids and their salts, alkylphenol sulfonic acids / condensed alkylphenol sulfonic acids and their salts, or mixtures or combinations thereof. Other examples of anionic surfactants considered suitable for use in this disclosure include alkali metal sulforicinates; sulfonated glycerol esters of fatty acids such as sulfonated monoglycerides of coconut oil; salts of sulfonated monovalent alcohol esters such as sodium oleylisethianate; metal soaps of fatty acids; amides of aminosulfonic acids, such as sodium salts of oleylmethyl taurine; sulfonated products of fatty acid nitriles, such as palmitonium sulfonate; alkali metal alkyl sulfates, such as sodium lauryl sulfate, ammonium lauryl sulfate, or triethanolamine lauryl sulfate; ether sulfates having alkyl groups having eight or more carbon atoms, such as sodium lauryl ether sulfate, ammonium lauryl ether sulfate, sodium alkyl aryl ether sulfate, and ammonium alkyl aryl ether sulfate; sulfates of polyoxyethylene alkyl ethers; and sodium, potassium, and amine salts of alkylnaphthalene sulfonic acids. Certain phosphate surfactants, including phosphate esters such as sodium lauryl phosphate ester, or those available under the trade name TRITON from Dow Chemical Company, are also considered suitable. A particularly desirable anionic surfactant is sodium dodecyl sulfate (SDS).

[0084] Cationic surfactants are also considered suitable for use in some embodiments of the manufacture of substrates in conjunction with this disclosure. In some embodiments, such as those including superabsorbent materials, the use of cationic surfactants may be less preferred due to potential interactions between the cationic surfactant and the superabsorbent material (which may be anionic). Foaming cationic surfactants include, but are not limited to, monocarbonyl ammonium salts, dicarbonyl ammonium salts, tricarbonyl ammonium salts, monocarbonyl phosphonium salts, dicarbonyl phosphonium salts, tricarbonyl phosphonium salts, carbonyl carboxyl salts, quaternary ammonium salts, imidazolines, ethoxylated amines, quaternary phospholipids, etc. Further examples of cationic surfactants include various fatty acid amines and amides and their derivatives, as well as salts of fatty acid amines and amides. Examples of aliphatic fatty acid amines include dodecylamine acetate, octadecylamine acetate, and acetates of amines of tallow fatty acids; homologues of aromatic amines containing fatty acids, such as dodecylaniline; fatty amides derived from aliphatic diamines, such as undecylimidazoline; fatty amides derived from aliphatic diamines, such as undecylimidazoline; fatty amides derived from disubstituted amines, such as oleylaminodiethylamine; derivatives of ethylenediamine; quaternary ammonium compounds and their salts, such as trimethylammonium tallow chloride, dioctadecyldimethylammonium chloride, didodecyldimethylammonium chloride, dihexylammonium chloride, alkyltrimethylammonium hydroxide, dioctadecyldimethylammonium hydroxide, trimethylammonium tallow chloride, trimethylammonium hydroxide, methylpolyoxyethylene cocoyl ammonium chloride, and dipalmitylhydroxyethylmethylammonium sulfate; amide derivatives of amino alcohols, such as β-hydroxyethylstearamide; and amine salts of long-chain fatty acids. Other examples of cationic surfactants considered suitable for use in this disclosure include benzalkonium chloride, benzyl chloride, cetrimonium bromide, distearate dimethyl ammonium chloride, tetramethyl ammonium hydroxide, etc.

[0085] Nonionic surfactants considered suitable for use in this disclosure include, but are not limited to, condensates of ethylene oxide with long-chain fatty alcohols or fatty acids, condensates of ethylene oxide with amines or amides, condensates of ethylene oxide and propylene oxide, fatty acid alkanolamides, and fatty amine oxides. Various other examples of nonionic surfactants include stearyl alcohol, sorbitan monostearate, octyl glucoside, octaethylene glycol monododecyl ether, lauryl glucoside, cetyl alcohol, cocoamide MEA, glyceryl monolaurate, polyoxyethylene alkyl ethers such as polyethylene glycol long-chain (12-14C) alkyl ethers, polyoxyethylene sorbitan ethers, polyoxyethylene alkoxylated esters, polyoxyethylene alkylphenol ethers, ethylene glycol-propylene glycol copolymers, polyvinyl alcohol, alkyl polysaccharides, polyethylene glycol sorbitan monooleate, octylphenol ethylene oxide, etc.

[0086] The foaming surfactant can be used in different amounts as needed to achieve the desired foam stability and air content in the foam. In some embodiments, the foaming surfactant may comprise between about 0.005% and about 5% of the foam (by weight). In some embodiments, the foaming surfactant may comprise between about 0.05% and 3% of the foam, or even between about 0.05% and about 2% of the foam (by weight).

[0087] fiber

[0088] As described above, the apparatus 10, 110, and methods described herein may include supplying fibers from a supply of fibers 18. In some embodiments, the fibers may be suspended in a fluid supply 16, 28, which may be a foam. A foam suspension of fibers may provide one or more fiber supplies. In some embodiments, the fibers used herein may include natural fibers and / or synthetic fibers. In some embodiments, the fiber supply 18 may include only natural fibers or only synthetic fibers. In other embodiments, the fiber supply 18 may include a mixture of natural and synthetic fibers. Some fibers used herein may be absorbent, while others may be non-absorbent. Non-absorbent fibers may provide characteristics to the substrate formed by the methods and apparatus described herein, such as improved fluid absorption or distribution.

[0089] A wide variety of cellulose fibers are considered applicable herein. In some embodiments, the fibers used may be conventional papermaking fibers, such as wood pulp fibers formed through various pulping processes, such as kraft pulp, sulfite pulp, bleached chemithermomechanical pulp (BCTMP), chemithermomechanical pulp (CTMP), pressure / pressure thermomechanical pulp (PTMP), thermomechanical pulp (TMP), thermomechanical chemimechanical pulp (TMCP), etc. By way of example only, fibers and methods for preparing wood pulp fibers are disclosed in US4793898, US4594130, US3585104, US5595628, US5595628, and US5522967, etc., issued to Laamanen et al. Furthermore, the fibers may be any wood pulp with a high average fiber length, wood pulp with a low average fiber length, or mixtures thereof. Examples of suitable high average length pulp fibers include softwood fibers, such as, but not limited to, northern softwood, southern softwood, mahogany, red cedar, hemlock, pine (e.g., southern pine), spruce (e.g., black spruce), etc. Examples of suitable low average length pulp fibers include hardwood fibers, such as, but not limited to, eucalyptus, maple, birch, poplar, etc.

[0090] Furthermore, if desired, secondary fibers derived from recycled materials, such as pulp from sources like newsprint, recycled paperboard, and office waste paper, can be used. In a particularly preferred embodiment, refined fibers are utilized in the tissue paper web, thereby reducing the total amount of virgin and / or high-average-fiber-length wood fibers (such as cork fibers).

[0091] Regardless of the source of the wood pulp fibers, the wood pulp fibers preferably have an average fiber length greater than about 0.2 mm and less than about 3 mm, such as about 0.35 mm and about 2.5 mm, or between about 0.5 mm and about 2 mm, or even between about 0.7 mm and about 1.5 mm.

[0092] In addition, other cellulose fibers that can be used in this disclosure include non-wood fibers. As used herein, the term "non-wood fiber" generally refers to cellulose fibers derived from the stems of non-woody monocotyledonous or dicotyledonous plants. Non-limiting examples of dicotyledonous plants that can be used to produce non-wood fibers include kenaf, jute, flax, ramie, and hemp. Non-limiting examples of monocotyledonous plants that can be used to produce non-wood fibers include cereal straw (wheat, rye, barley, oats, etc.), stalks (corn, cotton, sorghum, Heitzperrhoa, etc.), vines (bamboo, sisal, bagasse, etc.), and grasses (Miscanthus sinensis, Spanish grass, lemon, saba, switchgrass, etc.). In some other cases, non-wood fibers may be derived from aquatic plants such as water hyacinth, microalgae such as spirulina, and macroalgae such as red or brown algae.

[0093] Additionally, other cellulose fibers used to manufacture the substrates described herein may include synthetic cellulose fiber types formed by spinning, including rayon in all its types, and other fibers derived from viscose fibers or chemically modified cellulose, such as, for example, those available under the trade names LYOCELL and TENCEL.

[0094] In some embodiments, non-wood and synthetic cellulose fibers may have fiber lengths greater than about 0.2 mm, including, for example, average fiber dimensions between about 0.5 mm and about 50 mm, or between about 0.75 mm and about 30 mm, or even between about 1 mm and about 25 mm. Generally, when using fibers with relatively large average lengths, it is often advantageous to vary the amount and type of foaming surfactant. For example, in some embodiments, if fibers with relatively large average lengths are used, it may be beneficial to utilize relatively higher amounts of foaming surfactant to help achieve a foam with the desired foam half-life.

[0095] Other fibers that can be used in this disclosure include fibers resistant to forming fluids, i.e., those that are non-absorbent and whose flexural stiffness is substantially unaffected by the presence of the forming fluid. As mentioned above, the forming fluid will typically include water. By way of non-limiting example, water-resistant fibers include fibers such as polymer fibers comprising polyolefins, polyester (PET), polyamides, polylactic acid, or other fiber-forming polymers. Polyolefin fibers such as polyethylene (PE) and polypropylene (PP) are particularly suitable for this disclosure. In some embodiments, the non-absorbent fiber may be recycled fiber, compostable fiber, and / or marine-degradable fiber. Additionally, highly cross-linked cellulose fibers without significant absorption properties may also be used herein. In this regard, due to their very low level of water absorption, water-resistant fibers do not experience significant changes in flexural stiffness upon contact with an aqueous fluid and are therefore able to maintain an open composite structure when wetted. The fiber diameter can contribute to increased flexural stiffness. For example, PET fibers have higher flexural stiffness than polyolefin fibers, whether in a dry or wet state. The higher the fiber denier, the higher the flexural stiffness exhibited by the fiber. Water-resistant fibers ideally have a water retention value (WRV) of less than about 1, and more ideally between about 0 and about 0.5. In some respects, it is desirable that the fiber, or at least a portion thereof, comprises non-absorbent fibers.

[0096] Synthetic fibers and / or water-resistant fibers may have fiber lengths greater than about 0.2 mm, including, for example, having an average fiber size between about 0.5 mm and about 50 mm, or between about 0.75 mm and about 30 mm, or even between about 1 mm and about 25 mm.

[0097] In some implementations, the synthetic and / or water-resistant fibers may have a crimped structure to enhance the volumetric generation capability of the fiber substrate in foam formation. For example, PET crimped short fibers may be able to generate greater thickness (or result in lower sheet density) compared to straight PET short fibers with the same fiber diameter and fiber length.

[0098] In some embodiments, the total fiber content may be between about 0.01% and about 10% (by weight) of the foam, while in other embodiments it may be between about 0.1% and about 5% (by weight) of the foam.

[0099] adhesive

[0100] In some embodiments, fluid supplies 16, 28 may include an adhesive material. Adhesive materials that can be used in this disclosure may include, but are not limited to, thermoplastic adhesive fibers, such as PET / PE bicomponent adhesive fibers, and water-compatible adhesives, such as latex. In some embodiments, the adhesive material used herein may be in powder form, such as thermoplastic PE powder. Importantly, the adhesive may include an adhesive that is insoluble in water on a dry substrate. In some embodiments, the latex used in this disclosure may be cationic or anionic to facilitate application and adhesion to cellulose fibers that may be used herein. For example, latexes considered suitable include, but are not limited to, anionic styrene-butadiene copolymers, polyvinyl acetate homopolymers, vinyl acetate-ethylene copolymers, vinyl acetate-acrylic acid copolymers, ethylene-vinyl chloride copolymers, ethylene-vinyl chloride-vinyl acetate terpolymers, acrylic polyvinyl chloride polymers, acrylic polymers, nitrile polymers, and other suitable anionic latex polymers known in the art. Examples of such latexes are described in US4785030, granted to Hager; US6462159, granted to Hamada; US6752905, granted to Chuang et al., etc. Examples of suitable thermoplastic binder fibers include, but are not limited to, single-component and multi-component fibers of at least one thermoplastic polymer with a relatively low melting point, such as polyethylene. In some embodiments, short polyethylene / polypropylene sheath / core fibers may be used. The binder fibers may have the same length as those described above regarding synthetic cellulose fibers.

[0101] The binder in liquid form, such as a latex emulsion, may comprise between about 0% and about 10% of the foam (by weight). In some embodiments, the non-fibrous binder may comprise between about 0.1% and 10% of the foam (by weight), or even between about 0.2% and about 5%, or even between about 0.5% and about 2% of the foam (by weight). The binder fibers may be added proportionally to the other components during use to achieve the desired fiber ratio and structure while keeping the total solids content of the foam below the amounts described above. For example, in some embodiments, the binder fibers may comprise between about 0% and about 50% of the total fiber weight, more preferably between about 5% and about 40% of the total fiber weight in some embodiments.

[0102] Foam stabilizer

[0103] In some embodiments, if the fluid supplies 16, 28 are configured as foam, the foam may optionally also include one or more foam stabilizers known in the art, said foam stabilizers being compatible with the foam components and, additionally, not interfering with the hydrogen bonding between cellulose fibers. Foam stabilizers considered suitable for this disclosure include, but are not limited to, one or more zwitterionic compounds, amine oxides, alkylated polyepoxides, or mixtures or combinations thereof. Specific examples of foam stabilizers include, but are not limited to, cocoyl amine oxide, isononyl dimethyl amine oxide, n-dodecyl dimethyl amine oxide, etc.

[0104] In some embodiments, if used, the foam stabilizer may comprise between about 0.01% and about 2% of the foam (by weight). In some embodiments, the foam stabilizer may comprise between about 0.05% and 1% of the foam, or even between about 0.1% and about 0.5% of the foam (by weight).

[0105] Components

[0106] In the methods described herein, the foam formation process may include adding one or more components as additional additives to be incorporated into the substrate 12. For example, one such additional additive that may be added during the formation of the substrate 12 as described herein may be a superabsorbent material (SAM). SAM is typically provided in particulate form and, in some respects, may comprise a polymer of an unsaturated carboxylic acid or a derivative thereof. These polymers are typically made insoluble in water by crosslinking them with a difunctional or polyfunctional internal crosslinking agent, but water can swell them. These internally crosslinked polymers are at least partially neutralized and typically contain side-attached anionic carboxyl groups on the polymer backbone, which enable the polymer to absorb aqueous fluids, such as bodily fluids. Typically, the SAM particles are post-treated to crosslink the side-attached anionic carboxyl groups on the particle surface. SAM is manufactured using known polymerization techniques, ideally via gel polymerization in an aqueous solution. The product of this polymerization process is an aqueous polymer gel, i.e., a SAM hydrogel whose size is reduced to small particles by mechanical force, and then dried using drying procedures and equipment known in the art. After the drying process, the resulting SAM particles are pulverized to the desired particle size. Examples of superabsorbent materials include, but are not limited to, those described in US7396584, Dodge et al., US7935860, Azad et al., US2005 / 5245393, Bergam et al., and Chang et al., WO2008 / 027488. Additionally, to aid processing, SAM can be treated to make the material temporarily nonabsorbent during foam formation and the formation of highly expanded foam. For example, in one aspect, SAM can be treated with a water-soluble protective coating having a selected dissolution rate so that the SAM is substantially not exposed to the aqueous carrier until the highly expanded foam has formed and the drying operation begins. Alternatively, to prevent or limit premature expansion during processing, SAM can be introduced into the process at a low temperature.

[0107] In some embodiments incorporating SAM, SAM may constitute between approximately 0% and approximately 40% of the foam (by weight). In some embodiments, SAM may constitute between approximately 1% and approximately 30% of the foam (by weight), or even between approximately 10% and approximately 30% of the foam (by weight).

[0108] Other additives may include one or more wet strength additives, which may be added to the foam or fluid supply 16,28 to help improve the relative strength of the ultra-low density composite cellulose material. Such strength additives suitable for papermaking fibers and tissue paper manufacturing are known in the art. Temporary wet strength additives may be cationic, nonionic, or anionic. Examples of such temporary wet strength additives include PAREZ. TM631NC and PAREZ® 725 are temporary wet strength resins, which are cationic acetaldehyde-oxidized polyacrylamides available from Cytec Industries, West Paterson, NJ. These and similar resins are described in US3556932 and Williams et al., respectively. Further examples of temporary wet strength additives include dialdehyde starch and other aldehyde-containing polymers, such as those described in US6224714, Shannon et al., US6274667, Schroeder et al., US6287418, and Shannon et al., respectively.

[0109] Permanent wet-strength agents comprising cationic oligomers or polymers may also be used in this disclosure. Polyamide-polyamine-epiochlorohydrin type resins, such as KYMENE 557H sold by Solenis, are the most widely used permanent wet-strength agents and are suitable for use in this disclosure. Such materials have been described in the following patents: US3700623, US3772076, US3855158, US3899388, US4129528, US4147586, and US4222921, all granted to Keim et al. Other cationic resins include polyethyleneimine resins and amino plastic resins obtained by reacting formaldehyde with melamine or urea. In the manufacture of the composite cellulose products of this disclosure, permanent and temporary wet-strength resins may be used together. In addition, dry-strength resins may optionally be applied to the composite cellulose webs of this disclosure. Such materials may include, but are not limited to, modified starch and other polysaccharides such as cationic, amphoteric and anionic starch, as well as guar gum and locust bean gum, modified polyacrylamide, carboxymethyl cellulose, sugar, polyvinyl alcohol, chitosan, etc.

[0110] If used, such wet strength and dry strength additives may comprise between about 0.01% and about 5% of the dry weight of the cellulose fibers. In some embodiments, the strength additives may comprise between about 0.05% and about 2% of the dry weight of the cellulose fibers, or even between about 0.1% and about 1% of the dry weight of the cellulose fibers.

[0111] Other additional components may also be added to the foam, provided they do not significantly interfere with the formation of a highly expandable, stable foam, hydrogen bonding between cellulose fibers, or other desired properties of the web. As examples, additional additives may include, as needed, one or more pigments, opacifiers, antimicrobial agents, pH adjusters, skin-beneficial agents, odor absorbers, fragrances, thermally expandable microspheres, foam particles (such as pulverized foam particles), etc., to impart or improve one or more physical or aesthetic properties. In some embodiments, the composite cellulose web may include skin-beneficial agents, such as, for example, antioxidants, astringents, conditioning agents, emollients, deodorants, topical analgesics, film-forming agents, humectants, water-soluble growth promoters, pH adjusters, surface modifiers, skin care agents, etc.

[0112] When used, the various components should ideally comprise less than about 2% (by weight) of the foam, more ideally less than about 1% (by weight), or even less than about 0.5% (by weight).

[0113] In some embodiments, the solid content, including fibers or microparticles as described herein, ideally accounts for no more than about 40% of the foam. In some embodiments, cellulose fibers may account for between about 0.1% and about 5% of the foam, or between about 0.2% and about 4% of the foam, or even between about 0.5% and about 2% of the foam.

[0114] The methods and devices 10, 110, and 210 described herein can facilitate the formation of one or more components of a personal care product. For example, in one embodiment, the substrate 12 described herein can be an absorbent core for absorbent articles, such as, but not limited to, diapers, adult incontinence clothing, or feminine hygiene products. The substrate 12 described herein can also be used in other products, such as, but not limited to, facial tissues, wipes, and wipes.

[0115] Implementation plan:

[0116] Implementation Scheme 1: An apparatus for forming a substrate, the apparatus comprising: a first pump configured to pump a first fluid supply; a component feeding system including: a component supply region for receiving the supply of components; and an outlet conduit; an ejector in fluid communication with the outlet conduit of the component feeding system and with a second fluid supply, the ejector including a first discharge port; a headbox in fluid communication with the first fluid supply and the first discharge port of the ejector; and a forming surface configured to receive slurry transferred through the headbox.

[0117] Implementation Scheme 2: The device as described in Implementation Scheme 1, wherein the injector includes: a first inlet in communication with the supply fluid of the component; a second inlet in communication with the second fluid supply fluid; and an outlet.

[0118] Implementation Scheme 3: The device as described in Implementation Scheme 2, wherein the outlet conduit includes an outlet axis, and wherein the first inlet of the ejector includes a first inlet axis, the first inlet axis being coaxial with the outlet axis.

[0119] Implementation Scheme 4: The device as described in Implementation Scheme 2 or 3, wherein the outlet conduit includes an outlet axis, and wherein the discharge port includes a discharge axis, the discharge axis being coaxial with the outlet axis.

[0120] Implementation Scheme 5: The device as described in any one of Implementation Schemes 2 to 4, wherein the injector further includes a Venturi section, and wherein the distal end of the outlet conduit is disposed in the Venturi section of the injector.

[0121] Implementation Scheme 6: The device as described in any one of Implementation Schemes 2 to 5, wherein the second inlet is located upstream of the distal end of the outlet conduit of the component feeding system.

[0122] Implementation Scheme 7: The device as described in any of the preceding implementation schemes further includes a second mixing connector, the second mixing connector being in fluid communication with the first discharge port of the injector and in fluid communication with the first fluid supply, the second mixing connector including a second discharge port, the second discharge port being in fluid communication with the headbox.

[0123] Implementation Scheme 8: The equipment as described in Implementation Scheme 7, wherein the second discharge port is integrated with the headbox.

[0124] Implementation Scheme 9: The device as described in any of the preceding embodiments further includes: a second pump configured to pump a second fluid supply; a first tank configured to maintain the first fluid supply, the first tank being in fluid communication with the first pump; and a second tank configured to maintain the second fluid supply, the second tank being in fluid communication with the second pump.

[0125] Implementation Scheme 10: The device as described in any of the preceding embodiments, wherein the first fluid supply is a first foam, the first foam comprising the plurality of fibers, water and a surfactant, and wherein the component is a microparticle.

[0126] Implementation Scheme 11: An apparatus for forming a substrate, the apparatus comprising: a pump configured to pump a first fluid supply; a component feeding system including: a component supply region for receiving a component supply; and an outlet conduit including an outlet axis; an ejector in fluid communication with the component supply fluid and a second fluid supply fluid via the outlet conduit of the component feeding system, the ejector including a first discharge port; a mixing connector in fluid communication with the first discharge port of the ejector and the first fluid supply fluid, the mixing connector including a second discharge port; a headbox in fluid communication with the second discharge port of the mixing connector; and a forming surface configured to receive a resulting slurry transferred through the headbox.

[0127] Implementation Scheme 12: The device as described in Implementation Scheme 11, wherein the injector further comprises: a first inlet in communication with the supply fluid of the component; and a second inlet in communication with the second fluid supply fluid.

[0128] Implementation Scheme 13: The device as described in Implementation Scheme 12, wherein the first inlet of the injector includes a first inlet axis, and the first outlet of the injector includes an outlet axis, wherein the outlet axis is coaxial with the first inlet axis.

[0129] Implementation Scheme 14: The device as described in Implementation Scheme 12 or 13, wherein the injector further includes a Venturi section, and wherein the distal end of the outlet conduit is disposed in the Venturi section of the injector.

[0130] Implementation Scheme 15: The device as described in any one of Implementation Schemes 12 to 14, wherein the second inlet is located upstream of the distal end of the outlet conduit of the component feeding system.

[0131] Implementation Scheme 16: The device as described in any one of Implementation Schemes 11 to 15 further includes a second pump configured to pump the second fluid supply.

[0132] Implementation Scheme 17: An apparatus for forming a substrate, the apparatus comprising: a first pump configured to pump a first fluid supply; a component feeding system including: a component supply region for receiving the supply of components; and an outlet conduit including an outlet conduit axis; an ejector in fluid communication with the outlet conduit of the component feeding system and with the first fluid supply, the ejector including a discharge port; a headbox in fluid communication with the discharge port of the ejector; and a forming surface configured to receive slurry transferred through the headbox.

[0133] Implementation Scheme 18: The device as described in Implementation Scheme 17, wherein the injector includes: a first inlet in communication with the supply fluid of the component; and a second inlet in communication with the first fluid supply fluid.

[0134] Implementation Scheme 19: The device as described in Implementation Scheme 17 or 18, wherein the discharge port of the injector includes a discharge axis, and wherein the outlet axis of the outlet conduit is coaxial with the discharge axis.

[0135] Implementation Scheme 20: The device as described in any one of Implementation Schemes 17 to 19, wherein the injector further includes a Venturi section, and wherein the distal end of the outlet conduit is disposed in the Venturi section of the injector.

[0136] All relevant portions of the documents referenced in the specific implementation are incorporated herein by reference; any reference to any document should not be construed as an admission that it is prior art concerning the invention. In the event of any conflict between the meaning or definition of any term in this written document and any meaning or definition of a term in the documents incorporated by reference, the meaning or definition assigned to the term in this written document shall prevail.

[0137] While specific embodiments have been shown and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, all such changes and modifications falling within the scope of the invention are intended to be covered in the appended claims.

Claims

1. An apparatus for forming a substrate, the apparatus comprising: A first pump, configured to pump a first fluid supply; Component feeding system, the component feeding system comprising: A component supply area for receiving a supply of components, the components being maintained in a dry environment, wherein the components are particulate matter; and Outlet conduit; An ejector, the ejector being in fluid communication with the outlet conduit of the component feed system and with a second fluid supply containing water, wherein at least one of the first fluid supply and the second fluid supply comprises a plurality of fibers, the ejector comprising: A first inlet, which is in communication with the supply fluid of the component; A second inlet, which is in fluid communication with the second fluid supply; and First discharge outlet; The second inlet is located upstream of the distal end of the outlet conduit of the component feeding system; A headbox, the headbox being in fluid communication with the first fluid supply and the first discharge port of the ejector, wherein the resulting slurry comprises the first fluid supply, the second fluid supply, and the supply of the components; and A forming surface configured to receive the resulting slurry transferred through the headbox.

2. The device of claim 1, wherein the outlet conduit includes an outlet axis, and wherein the first inlet of the ejector includes a first inlet axis, the first inlet axis being coaxial with the outlet axis.

3. The device of claim 1, wherein the outlet conduit includes an outlet axis, and wherein the discharge port includes a discharge axis, the discharge axis being coaxial with the outlet axis.

4. The device of claim 1, wherein the injector further includes a venturi section, and wherein the distal end of the outlet conduit is disposed in the venturi section of the injector.

5. The device of claim 1, further comprising a second mixing connector, the second mixing connector being in fluid communication with the first discharge port of the injector and in fluid communication with the first fluid supply, the second mixing connector including a second discharge port, the second discharge port being in fluid communication with the headbox.

6. The device of claim 5, wherein the second discharge port is integrated with the headbox.

7. The device as claimed in claim 1, further comprising: A second pump, configured to pump a second fluid supply; A first tank, configured to maintain the first fluid supply, is in fluid communication with the first pump; as well as A second tank, configured to maintain the supply of the second fluid, is in fluid communication with the second pump.

8. The device of claim 1, wherein the first fluid supply is a first foam comprising the plurality of fibers, water and a surfactant, and wherein the second fluid supply is a second foam.

9. An apparatus for forming a substrate, the apparatus comprising: A first pump, configured to pump a first fluid supply; Component feeding system, the component feeding system comprising: A component supply area for receiving a supply of components, the components being maintained in a dry environment, wherein the components are particulate matter; and An outlet conduit, the outlet conduit including an outlet axis; An ejector, the ejector being in communication with the supply fluid of the component and with a second fluid supply fluid comprising water via the outlet conduit of the component feed system, the ejector comprising: A first inlet, which is in communication with the supply fluid of the component; A second inlet, which is in fluid communication with the second fluid supply; and First discharge outlet; The second inlet is located upstream of the distal end of the outlet conduit of the component feeding system; A mixing connector, which is in fluid communication with the first discharge port of the injector and with the first fluid supply, the mixing connector including a second discharge port; A headbox, the headbox being in fluid communication with the second discharge port of the mixing joint, wherein the resulting slurry comprises the first fluid supply, the second fluid supply, and the supply of the components; and A forming surface configured to receive the resulting slurry transferred through the headbox.

10. The device of claim 9, wherein the first inlet of the injector includes a first inlet axis, and the first outlet of the injector includes a first outlet axis, wherein the first outlet axis is coaxial with the first inlet axis.

11. The device of claim 9, wherein the injector further includes a venturi section, and wherein the distal end of the outlet conduit is disposed in the venturi section of the injector.

12. The apparatus of claim 9, further comprising a second pump configured to pump the second fluid supply, wherein the second fluid supply is a second foam.

13. An apparatus for forming a substrate, the apparatus comprising: A first pump, configured to pump a first fluid supply containing water; Component feeding system, the component feeding system comprising: A component supply area for receiving a supply of components, the components being maintained in a dry environment, wherein the components are particulate matter; and An outlet conduit, the outlet conduit including an outlet conduit axis; An ejector, which is in fluid communication with the outlet conduit of the component feed system and with the first fluid supply, the ejector comprising: A first inlet, which is in communication with the supply fluid of the component; A second inlet, which is in fluid communication with the first fluid supply; and Emission outlet; The second inlet is located upstream of the distal end of the outlet conduit of the component feeding system; A headbox, the headbox being in fluid communication with the outlet of the ejector, wherein the resulting slurry comprises the first fluid supply and the supply of the components; and A forming surface configured to receive the resulting slurry transferred through the headbox.

14. The device of claim 13, wherein the discharge port of the injector includes a discharge axis, and wherein the outlet conduit axis of the outlet conduit is coaxial with the discharge axis.

15. The device of claim 13, wherein the injector further includes a venturi section, and wherein the distal end of the outlet conduit is disposed in the venturi section of the injector.

Images