Recycled material pellets

Abstract

Herein is described a recycled material pellet comprising: shredded glass fiber waste material comprising glass fibers and a thermoplastic binder; wherein the thermoplastic binder constitutes at least about 2 wt.% of the recycled material pellet.

Description

[0001] Recycled Material Pellets

[0002] Field of the Invention

[0003] The present invention relates to a recycled material pellet comprising shredded glass fiber waste material, in particular a recycled material pellet comprising shredded glass fiber waste material from recycled composite materials wherein the shredded glass fiber waste material comprises glass fibers and thermoplastic binder. The present invention also relates to a method of producing said recycled material pellet.

[0004] Background

[0005] Composite materials containing glass fibers are used for a variety of components and products. Notably, glass fibers reinforce structural components such as automotive parts or related components. Composite materials containing glass fibers are also used for ceiling, flooring and wall boards.

[0006] Glass fiber waste commonly ends up in landfill due to handling difficulties stemming from the low density and high dust content. New solutions are needed such that the glass fiber waste may be recovered and reused.

[0007] It is desired to provide an improved and efficient manner of recycling glass fiber containing composite materials. It may also be desired to provide a manner of recycling glass fiber containing composite materials that retains a relatively long fiber length to allow for re-use in structural components.

[0008] Summary of the Invention

[0009] At its most general, the present invention provides a recycled material pellet comprising shredded glass fiber waste material, the shredded glass fiber waste material comprising glass fibers and a thermoplastic binder.

[0010] In an aspect, the present invention provides a recycled material pellet comprising: shredded glass fiber waste material comprising glass fibers and a thermoplastic binder; wherein the thermoplastic binder constitutes at least about 2 wt.% of the recycled material pellet. The present inventors have found that the present invention allows for the provision of a recycled material pellet that allows shredded glass fiber waste material to be easily handled. The present inventors have found that the present invention provides improvements in the efficiency of recycling glass fiber waste materials which contain glass fibers and thermoplastic binder. The glass fiber waste material may originate from recycled glass fiber containing composite materials. The present inventors have surprisingly found that the glass fibers and thermoplastic binder in glass fiber waste materials can be incorporated into a recycled material pellet without the addition of other materials and reused in other components and products. Composite materials containing glass fibers and thermoplastic binder are commonly shredded to allow for recycling and re-use of the materials. This process however has disadvantages and results in the production of 'fines' and dust, which restricts the handling, dosing and application of the shredded glass fiber waste materials. The provision of recycled material pellets as described herein has been found to surprisingly allow for improved ease of handling of shredded glass fiber waste materials, through the reduction of dust and 'fines'. The recycled material pellets provided are also easier to dose than traditional shredded glass fiber waste materials.

[0011] In an embodiment, the shredded glass fiber waste material constitutes at least 90 wt.% of the recycled material pellet, for example at least about 95 wt.%, or at least about 98 wt.% if the recycled material pellets. In embodiments, the pellets consist of or consist essentially of shredded glass fiber waste material. This may be advantageous as it increases the efficiency of recycling the shredded glass fiber waste material. Furthermore, this may lead to ease of processing and manufacturing.

[0012] In another embodiment, the thermoplastic binder constitutes up to about 30 wt.% of the recycled material pellet. In an embodiment, the thermoplastic binder constitutes from about 2 wt.% to about 25 wt.% of the recycled material pellet. The present inventors have found that a higher amount of thermoplastic binder leads to improved pelletisation. Different amounts of thermoplastic binder may be preferential for different shredded glass fiber waste materials.

[0013] In an embodiment, the thermoplastic binder constitutes up to about 30 wt.% of the recycled material pellet and the glass fibers constitute at least 25 wt.% of the recycled material pellet.

[0014] Different ratios of thermoplastic binder and glass fibers will produce different pellets. The amounts of thermoplastic binder and glass fibers allows for the process to be tailored towards the end use of the recycled material pellet, and this allows for different shredded glass fiber waste materials to be used. In some embodiments, the recycled material pellet has a density within the range of about 150 kg / m3to about 1000 kg / m3, for example the recycled material pellet may have a density within the range of about 300 kg / m3to about 800 kg / m3.

[0015] A density within the above ranges may be beneficial as the present inventors have found that the ease of handling may be improved and dust content reduced of the recycled material pellet compared to the shredded glass fiber waste material.

[0016] In an embodiment, the glass fibers have an aspect ratio of at least 5:1. It may be advantageous to retain a glass fiber aspect ratio of at least 5:1 to allow for the recycled material pellets to be utilised in reinforcement applications such as in the manufacture of structural components.

[0017] In an embodiment, the glass fibers have a fiber length of at least about 0.5 mm. The provision of such a recycled material pellet containing glass fibers with a relatively long fiber length, for example at least about 0.5 mm, allows the pellets to be used in reinforcement application due to the associated advantageous mechanical properties.

[0018] In an embodiment, the recycled material pellet has a diameter in the range of about 2 to about 10 mm. In an embodiment, the recycled material pellet has a length in the range of about 1 to about 50 mm.

[0019] In another aspect, the present invention provides a method of producing a recycled material pellet, the method comprising: providing a shredded glass fiber waste material comprising glass fibers and a thermoplastic binder, the thermoplastic binder constituting at least about 2 wt.% of the shredded glass fiber waste material; and compacting the shredded glass fiber waste material to form a recycled material pellet.

[0020] In an embodiment, compacting the shredded glass fiber waste material forms a recycled material pellet having a density within the range of about 150 kg / m3to about 1000 kg / m3. This may be beneficial for handling the shredded glass fiber waste material, for storage of the shredded glass fiber waste material and / or for application of the shredded glass fiber waste material.

[0021] In an embodiment, compacting the shredded glass fiber waste material is achieved at a temperature of at least 40 °C, for example, at a temperature of at least 60 °C. The present inventors have found that it may be beneficial to use heat to form the pellet. The application of heat may result in higher quality pelletisation, for example by allowing for the formation of pellets containing glass fibers with improved length (for example by reducing the amount of compaction required to form the pellet), for example glass fibers having a length of at least about 0.5mm which are useful in reinforcement applications.

[0022] In another aspect, the present invention provides a recycled material pellet product produced according to the method described herein.

[0023] Overall, the present inventors have found that the present invention allows for shredded glass fiber waste material to be recycled and reused. The recycled material pellets display improved flowability and handleability. The present inventors have also found that the retention of glass fiber length allows for retention of mechanical properties and as such increases the utility of shredded glass fiber waste material. The higher bulk density of the recycled material pellets compared to the shredded glass fiber waste materials also allows the same mass of glass fibers to occupy a smaller volume which is also advantageous for transportation and storage. The method of producing the recycled material pellet and therefore recycling the glass fibers and thermoplastic binder allows for relatively straightforward processing of waste glass fiber containing composite materials. The method also provides for ease of processing pellets containing glass fibers through dosing and mechanical transportation or pneumatic transportation. The pellets described here may also be used to produce recycled glass, for example by burning the pellets to remove binder material and melting the glass fibers. The present inventors found that pellets described herein may be used in reinforcement applications, for example in the manufacture of automotive parts, particularly when the pellets contain glass fibers having a fiber length of at least about 0.5 mm.

[0024] In another aspect, the present invention provides a recycled material pellet comprising: shredded glass fiber waste material comprising glass fibers and a thermoplastic binder; wherein the thermoplastic binder constitutes at least about 2 wt.% of the recycled material pellet and wherein the shredded glass fiber waste material constitutes at least 90 % of the recycled material pellet.

[0025] In another aspect, the present invention provides a recycled material pellet comprising: a shredded glass fiber waste material comprising glass fibers and a thermoplastic binder; wherein the thermoplastic binder constitutes up to about 15 wt.% of the recycled material pellet and wherein the glass fibers constitute at least 80 wt.% of the recycled material pellet; and wherein the recycled material pellet has a density within the range of about 150 kg / m3to about 1000 kg / m3.

[0026] In a further aspect, the present invention provides a recycled material pellet consisting of: compacted shredded glass fiber waste material consisting of glass fibers and a thermoplastic binder; wherein the thermoplastic binder constitutes at least about 2 wt.% of the recycled material pellet.

[0027] The invention includes the combination of the embodiments, aspects and preferred features described herein except where such a combination is clearly impermissible or expressly avoided.

[0028] Brief Description of the Figures

[0029] Embodiments and experiments illustrating the principles of the invention will be discussed with reference to the accompanying figures in which:

[0030] Figure 1 is a photograph of a glass fiber waste material used by the method of Example 9 described herein; and

[0031] Figure 2 is a photograph of a plurality of recycled material pellets formed by the method of Example 9 described herein.

[0032] Detailed Description

[0033] Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art.

[0034] Recycled Material Pellet

[0035] Described herein is a recycled material pellet comprising shredded glass fiber waste material, the shredded glass fiber waste material comprising glass fibers and a thermoplastic binder, wherein the thermoplastic binder constitutes at least about 2 wt.% of the recycled material pellet.

[0036] The term "glass fibers" is used herein to refer to a plurality of continuous glass filaments (the term "continuous" as used here is used to refer to a fiber / filament that has a length many times longer than its diameter, for example at least about 5000 times longer than its diameter, e.g., at least about 10 000 times longer than its diameter). The glass fibers used in the composite materials making up structural components such as automotive components may be provided as glass fiber strands (or tows). The glass fibers described herein may have a sizing on their surface, for example a sizing that was applied to the glass fibers during their formation. The sizing can include components such as a film former, lubricant, coupling agent, etc. that facilitate formation of the glass fibers and / or use thereof in a matrix resin. In some embodiments, the glass fibers include a polyester compatible sizing or an epoxy compatible sizing.

[0037] Any suitable glass reinforcing fibers, for example, glass fibers made from E glass, E-CR glass (such as Advantex™ glass fibers available from Owens Corning), C glass, H glass, S glass, and AR glass types can be used in composite materials.

[0038] The pellets described herein are formed from shredded glass fiber waste material, the term "shredded glass fiber waste material" is used herein to refer to waste materials containing glass fibers and thermoplastic binder, where the waste materials have been broken up during removal of the glass fiber waste material from its original location, or shredded / cut / broken prior to compaction as described herein (for example shredded / cut / broken in order to be placed into a compacting apparatus). Examples of glass fiber waste materials include ceiling boards, gypsum boards, flooring boards and wall boards containing glass fiber non-woven veils. Other examples of glass fiber waste materials include non-woven materials such as chopped strand mat (CSM), for example, CSM with thermoplastic binder and optionally as CSM areal weight in the range of about 150 to about 900 g / m2. However, any waste material including glass fibers and thermoplastic binders may be used. The waste material may also include fillers, for example mineral fillers.

[0039] The glass fibers of the shredded glass fiber waste material before it is formed into pellets generally have a fiber length within the range of about 0.1 to about 200 mm, a filament diameter of at least about 5 pm and an aspect ratio of at least 5:1.

[0040] The glass fibers of the pellets described herein, may have a fiber length (i.e., the length of the glass fibers of the shredded waste material after compaction) of up to about 50 mm, for example up to about 40 mm, up to about 30 mm, up to about 20 mm, or up to about 10 mm. In preferred embodiments, the glass fibers of the pellets described herein, have a fiber length (i.e., the length of the glass fibers of the shredded waste material after compaction) of at least about 0.5 mm. The fiber length of the glass fibers may be measured using microscopic analysis, for example microscopic analysis of the glass fibers after burning the pellet to remove the binder.

[0041] In embodiments, the glass fibers in the shredded glass fiber waste material prior to and after compaction have a filament diameter in the range of about 5 pm to about 25 pm, for example, the glass fibers have a filament diameter in the range of about 10 pm to about 20 pm, or about 15 pm to about 20 pm.

[0042] The glass fibers may constitute at least about 10 wt.% of the recycled material pellet, for example, at least about 15 wt.%, at least about 20 wt.%, at least about 25 wt.%, at least about 30 wt.%, at least about 35 wt.%, at least about 40 wt.%, at least about 45 wt.%, at least about 50 wt.%, at least about 55 wt.%, at least about 60 wt.%, at least about 65 wt.%, at least about 70 wt.%, at least about 75 %, at least about 80 wt.%, at least about 82.5 wt.%, at least about 85 wt.%, at least about 87.5 wt.%, at least about 90 wt.%, at least about 92.5 wt.%, at least about 95 wt.%, at least about 97wt.% , or at least about 98 wt.% of the recycled material pellet.

[0043] In embodiments, the glass fibers may constitute from about 10 wt.% to about 98 wt.% of the recycled material pellet, for example, from about 15 wt.% to about 98 wt.% of the recycled material pellet, from about 20 wt.% to about 98 wt.% of the recycled material pellet, from about 25wt.% to about 98 wt.% of the recycled material pellet, from about 30 wt.% to about 98 wt.% of the recycled material pellet, from about 40 wt.% to about 98 wt.% of the recycled material pellet, from about 50 wt.% to about 98 wt.% of the recycled material pellet, from about 60 wt.% to about 98 wt.% of the recycled material pellet, from about 65 wt.% to about 98 wt.% of the recycled material pellet, from about 70 wt.% to about 98 wt.% of the recycled material pellet, from about 75 wt.% to about 98 wt.% of the recycled material pellet, from about 80 wt.% to about 98 wt.% of the recycled material pellet, or from about 90 wt.% to about 98 wt.% of the recycled material pellet.

[0044] In embodiments, at least 60 wt.% of the glass fibers in the shredded glass fiber waste material prior to compaction have a fiber length of at least about 0.5 mm, for example at least about 1 mm, at least about 2.5 mm, at least about 5 mm, at least about 7.5 mm, or at least about 10 mm. In embodiments, at least 70 wt.% of the glass fibers in the shredded glass fiber waste material prior to compaction have a fiber length of at least about 0.5 mm, for example at least 70 wt.% of the glass fibers in the shredded glass fiber waste material prior to compaction have a fiber length of at least about 1 mm, at least about 2.5 mm, at least about 5 mm, at least about 7.5 mm or at least about 10 mm. In embodiments, at least 80 wt.% of the glass fibers in the shredded glass fiber waste material prior to compaction have a fiber length of at least about 0.5 mm, for example at least 80 wt.% of the glass fibers in the shredded glass fiber waste material prior to compaction have a fiber length of at least about 1 mm, at least about 2.5 mm, at least about 5 mm, at least about 7.5 mm or at least about 10 mm. The fiber length of the glass fibers may be measured using microscopic analysis.

[0045] In embodiments, the glass fibers in the shredded glass fiber waste material (i.e., glass fibers of the shredded glass fiber waste material prior to compaction / pelletisation) have a fiber length in the range of about 0.5 mm to about 50 mm, for example, the glass fibers in the shredded glass fiber waste material have a fiber length in the range of about 0.5 mm to about 40 mm. In embodiments, the glass fibers have a fiber length in the range of about 0.5 mm to about 50 mm prior to compacting, for example, the glass fibers have a fiber length in the range of about 0.5mm to about 50 mm, in the range of about 0.5 mm to about 25 mm, in the range of about 0.5 mm to about 12.5 mm, in the range of about 0.5 mm to about 10 mm, in the range of about 0.5 mm to about 7.5 mm, in the range of about 0.5 mm to about 5 mm, in the range of about 0.5 mm to about 2.5 mm, in the range of about 0.5 mm to about 1 mm, in the range of about 1 mm to about 50 mm, in the range of about 1 mm to about 25 mm, in the range of about 1 mm to about 12.5 mm, in the range of about 1 mm to about 10 mm, in the range of about 1 mm to about 7.5 mm, in the range of about 1 mm to about 5 mm, in the range of about 1 mm to about 2.5 mm, in the range of about 2.5 mm to about 50 mm, in the range of about 2.5 mm to about 25 mm, in the range of about 2.5 mm to about 10 mm, in the range of about 2.5 mm to about 7.5 mm, in the range of about 2.5 mm to about 5mm, in the range of about 5 mm to about 50 mm, in the range of about 5 mm to about 25 mm, in the range of about 5 mm to about 10 mm, in the range of about 5 mm to about 7.5 mm, in the range of about 7.5 mm to about 50 mm, in the range of about 7.5 mm to about 25 mm, in the range of about 7.5 mm to about 10 mm, in the range of about 10 mm to about 50 mm, in the range of about 10 mm to about 25 mm, in the range in the range of about 25 mm to about 50 mm. The fiber length of the glass fibers may be measured using microscopic analysis.

[0046] In embodiments, in the range of 40 wt.% to 99 wt.% of the glass fibers in the shredded glass fiber waste material (i.e., glass fibers of the shredded glass fiber waste material prior to compaction / pelletisation) have a fiber length in the range of about 0.2 mm to about 10 mm. For example, at least about 45 wt.% of the glass fibers may have a fiber length in the range of about 0.5 mm to about 7 mm, at least about 65 wt.% of the glass fibers may have a fiber length in the range of about 0.5 mm to about 7 mm, or at least about 85 wt.% of the glass fibers may have a fiber length in the range of about 0.5 mm to about 7 mm. In embodiments, at least 60 wt.% of the glass fibers in the shredded glass fiber waste material (i.e., glass fibers of the shredded glass fiber waste material prior to compaction / pelletisation) have an aspect ratio of at least about 5:1, for example, at least 60 wt.% of the glass fibers have an aspect ratio of at least about 10:1, at least about 50:1, at least about 100:1, at least about 250:1, at least about 500:1, or at least about 1000:1. In embodiments, at least 70 wt.% of the glass fibers have an aspect ratio of at least about 5:1, for example, at least 70 wt.% of the glass fibers have an aspect ratio of at least about 10:1, at least about 50:1, at least about 100:1, at least about 250:1, at least about 500:1, or at least about 1000:1. In embodiments, at least 80 wt.% of the glass fibers have an aspect ratio of at least about 5:1, for example, at least 80 wt.% of the glass fibers have an aspect ratio of at least about 10:1, at least about 50:1, at least about 100:1, at least about 250:1, at least about 500:1, or at least about 1000:1. In embodiments, at least 90 wt.% of the glass fibers have an aspect ratio of at least about 5:1, for example, at least 90 wt.% of the glass fibers have an aspect ratio of at least about 10:1, at least about 50:1, at least about 100:1, at least about 250:1, at least about 500:1, or at least about 1000:11. In embodiments, at least 95 wt.% of the glass fibers have an aspect ratio of at least about 5:1, for example, at least 95 wt.% of the glass fibers have an aspect ratio of at least about 10:1, at least about 50:1, at least about 100:1, at least about 250:1, at least about 500:1, or at least about 1000:1. The aspect ratio of the glass fibers in the shredded glass fiber waste material may be determined by microscopic analysis.

[0047] The recycled material pellet comprises thermoplastic binder.

[0048] The thermoplastic binder constitutes up to about 30 wt.% of the recycled material pellet. In embodiments, the thermoplastic binder constitutes up to about 30 wt.% of the recycled material pellet, for example up to about 25 wt.%, up to about 20 wt.%, up to about 15 wt.%, up to about 10 wt.%, up to about 7.5 wt.%, up to about 5 wt.%, up to about 2.5 wt.%, up to about 2 wt.%, or up to about 1 wt.% of the recycled material pellet.

[0049] The thermoplastic binder constitutes at least about 2 wt.% of the recycled material pellet. In embodiments, the thermoplastic binder constitutes, for example, at least about 5 wt.%, at least about 10 wt.%, at least about 15 wt.%, at least about 20 wt.%, at least about 25 wt.%, or at least about 30 wt.% of the recycled material pellet. In embodiments, the thermoplastic binder constitutes in the range of about 2 wt.% to about 30 wt.% of the recycled material pellet, for example, from about 2 wt.% to about 30 wt.%, or from about 5 wt.% to about 30 wt.%, or from about 10 wt.% to about 30 wt.%, or from about 30 wt.% to about 25 wt.%, or from about 20 to about 30 wt.%, or from about 25 to about 30 wt.% of the recycled material pellet, or for example, from about 2 wt.% to about 25 wt.%, or from about 5 wt.% to about 25 wt.%, or from about 10 wt.% to about 25 wt.%, or from about 15 wt.% to about 25 wt.%, or from about 20 to about 25 wt.% of the recycled material pellet, or for example, from about 2 wt.% to about 20 wt.%, or from about 5 wt.% to about 20 wt.%, or from about 10 wt.% to about 20 wt.%, or from about 15 wt.% to about 20 wt.% of the recycled material pellet, or for example, from about 2 wt.% to about 15 wt.%, or from about 5 wt.% to about 15 wt.%, or from about 10 wt.% to about 15 wt.% of the recycled material pellet, or for example, from about 2 wt.% to about 10 wt.%, or from about 5 wt.% to about 10 wt.% of the recycled material pellet, or for example from about 2 wt.% to about 5 wt.% of the recycled material pellet.

[0050] In embodiments, the thermoplastic binder has a glass transition temperature of up to about 90 °C, for example up to about 85 °C, up to about 80°C, up to about 75°C, up to about 70 °C, up to about 65 °C, up to about 60 °C, or up to about 55 °C. In embodiments, the thermoplastic binder has a glass transition temperature of at least about 30 °C, for example at least about 40 °C, or at least about 50 °C. In embodiments, the thermoplastic binder has a glass transition temperature in the range of about 30 °C to about 90 °C, for example about 55 °C to about 70 °C, or about 60 °C to 90 °C.

[0051] The glass transition temperature of the thermoplastic binder may be determined using differential scanning calorimetry (DSC) according to EN ISO 1153357-2 (determination of glass transition temperature). The glass transition temperature of the thermoplastic binder may be determined using differential scanning calorimetry (DSC) according to EN ISO 1153357-2 (determination of glass transition temperature) wherein the glass transition temperature is determined as the value provided on the second heating cycle. The glass translation temperature of the thermoplastic binder may be determined according to the EN ISO 1153357-2 test method by heating the thermoplastic binder under an air flow of 80 mL / min at a heating rate of lOK / min, heating from - 60 °C to 120 °C. In embodiments, the glass translation temperature of the thermoplastic binder may be determined according to the EN ISO 1153357-2 test method by heating the thermoplastic binder under an air flow of 80 mL / min at a heating rate of lOK / min, heating from - 60 °C to 120 °C and then holding for 5 mins at 120 °C before cooling from 120 °C to - 60 °C at a cooling rate of lOK / min and then holding for 5 mins at - 60 °C before heating from - 60 °C to 120 °C again at a heating rate of lOK / min the glass transition temperature is determined as the value provided on the second heating cycle.

[0052] In embodiments, the thermoplastic binder comprises or is composed of a thermoplastic resin selected from an epoxy resin or a polyester resin or a polyvinyl alcohol resin. In embodiments, the recycled material pellet has a density within the range of about 150 kg / m3to about 1000 kg / m3. In some embodiments, the recycled material pellet has a density of up to about 900 kg / m3, for example up to about 800 kg / m3, up to about 700 kg / m3, up to about 600 kg / m3, or up to about 500 kg / m3. In some embodiments, the recycled material pellet has a density of at least about 200 kg / m3, for example at least about 250 kg / m3, at least about 300 kg / m3, at least about 350 kg / m3, at least about 400 kg / m3, at least about 450 kg / m3, or at least about 500 kg / m3. In some embodiments, the recycled material pellet has a density within the range of about 150 kg / m3to about 800 kg / m3, for example about 200 kg / m3to about 750 kg / m3, about 200 kg / m3to about 700 kg / m3, about 200 kg / m3to about 650 kg / m3, about 200 kg / m3to about 600 kg / m3, about 200 kg / m3to about 550 kg / m3, about 200 kg / m3to about 500 kg / m3, about 250 kg / m3to about 800 kg / m3, about 250 kg / m3to about 700 kg / m3, about 250 kg / m3to about 600 kg / m3, about 250 kg / m3to about 500 kg / m3, about 300 kg / m3to about 800 kg / m3, about 300 kg / m3to about 700 kg / m3, about 300 kg / m3to about 600 kg / m3, about 300 kg / m3to about 700 kg / m3, about 300 kg / m3to about 600 kg / m3, about 400 kg / m3to about 800 kg / m3, about 400 kg / m3to about 700 kg / m3, or about 400 kg / m3to about 600 kg / m3. The density of a recycled material pellet may be measured using standard density displacement methodology.

[0053] In embodiments, the recycled material pellet has a diameter of less than about 60 mm, less than about 50 mm, less than about 40 mm, less than about 30 mm, less than about 20 mm, less than about 10 mm, less than about 8 mm, or less than about 6 mm, or less than about 4 mm. For example, the diameter of the recycled material pellet may be at least about 2 mm, or at least about 3 mm, for example the diameter of the recycled material pellet may be in range of 2 to 10 mm. For example, the diameter of the recycled material pellet may be at least about 5 mm, or at least 10 mm, or at least about 20 mm, for example the diameter of the recycled material pellet may be in range of 5 to 30 mm.

[0054] In embodiments, the recycled material pellet may have a length of up to about 100 mm, for example up to about 50 mm. In embodiments, the length of the recycled material pellet may be in the range of about 1 to about 50 mm, for example about 5mm to about 50 mmm, or about 10 mm to about 40 mm, or about 15 to 20 mm . In embodiments, the length of the recycled material pellet may be at least about 1 mm.

[0055] In embodiments, the recycled material pellet comprises glass fibers and thermoplastic binder. In embodiments the recycled material pellet comprises additional fibers in addition to glass fibers and thermoplastic binder. Examples of other fibers which may be included include polymer fibers such as PET, or carbon fibers. In embodiments, the additional fibers may constitute up to about 10 wt.% of the recycled material pellet, for example up to about 5 wt.%, up to about 3 wt.%, up to about 2 wt.%, up to about 1 wt.%, up to about 0.5 wt.%, or up to about 0.1 wt.% of the recycled material pellet.

[0056] In embodiments, the recycled material pellet comprises glass fibers and thermoplastic binder. In embodiments the recycled material pellet may comprise a filler in addition to the glass fibers and thermoplastic binder. Examples of fillers which may be included in the shredded glass waste material include mineral fillers such as calcium carbonate, titanium oxide and / or aluminium trihydrate. In embodiments, the pellet may contain up to about 70 wt.% of fillers by total weight of the pellet, 65 wt.% of fillers by total weight of the pellet, 60 wt.% of fillers by total weight of the pellet, for example up to about 55 wt.%, up to about 50 wt.%, up to about 45 wt.%, up to about 40 wt.%, up to about 35 wt.%, up to about 30 wt.%, up to about 25 wt.%, or up to about 20 wt.%. In embodiments, the pellet may contain from about 0 to about 60 wt.% of fillers, for example from 0 to about 40 wt.%, 0 to about 30 wt.%, 0 to 20 wt.% of fillers by total weight of the pellet. In embodiments, the pellet contains substantially no filler (for example less than about 5 wt.% filler, less than about 3 wt.% filler, less than about 2 wt.% filler, less than about 1 wt.% filler, or less than about 0.5 wt.% filler by total weight of the pellet).

[0057] In embodiments, the recycled material pellet consists of shredded glass fiber waste materials consisting of glass fibers and thermoplastic binder. In other words, in embodiments, the recycled material pellet only contains glass fiber waste materials of glass fibers and thermoplastic binder, and there are no additional materials such as fillers in the recycled material pellet.

[0058] In some embodiments, the recycled material pellet consists of compacted glass fiber waste material, the glass fiber waste material consisting of glass fibers and thermoplastic binder, the glass fibers constituting about 65 wt.% to about 98 wt.% of the glass fiber waste material and the thermoplastic binder constituting 2-35 wt.% of the glass fiber waste material. In some embodiments, the recycled material pellet consists of compacted glass fiber waste material, the glass fiber waste material consisting of glass fibers and thermoplastic binder, the glass fibers constituting about 70 wt.% to about 98 wt.% of the glass fiber waste material and the thermoplastic binder constituting 2-30 wt.% of the glass fiber waste material. In some embodiments, the recycled material pellet consists of compacted glass fiber waste material, the glass fiber waste material consisting of glass fibers and thermoplastic binder, the glass fibers constituting about 80 wt.% to about 98 wt.% of the glass fiber waste material and the thermoplastic binder constituting 2-20 wt.% of the glass fiber waste material. In some embodiments, the recycled material pellet consists of compacted glass fiber waste material, the glass fiber waste material consisting of glass fibers and thermoplastic binder, the glass fibers constituting about 90 wt.% to about 98 wt.% of the glass fiber waste material and the thermoplastic binder constituting 2-10 wt.% of the glass fiber waste material.

[0059] An example of a suitable thermoplastic binder is polyvinyl alcohol.

[0060] Method of producing a recycled material pellet

[0061] Described herein is a method providing a shredded glass fiber waste material comprising glass fibers and a thermoplastic binder, the thermoplastic binder constituting at least about 2 wt.% of the shredded glass fiber waste material; and compacting the shredded glass fiber waste material to form a recycled material pellet.

[0062] In embodiments, the thermoplastic binder has a dynamic viscosity, q, at 130 °C in the range of about 1 to about 400 Pa.s, for example about 10 to about 400 Pa.s. The dynamic viscosity, q, at 130 °C of the thermoplastic binder may be determined using a oscillatory rheometer at 0.1% deformation in plan-plan geometry, a frequency of 1 Hz with a binder sample having a thickness of 400 pm and diameter of 25 mm, employing a heating-cooling-heating cycle which heats from 30°C- 130°C at a rate of 3°C / min, cooling from 130°C-30°C and heating from 30°C-130°C at a rate of 3°C / min.

[0063] In embodiments, producing a recycled material pellet may comprise compacting the shredded glass fiber waste material at a pressure in the range of about 5 MPa to about 300 MPa, for example in the range of about 10 MPa to about 300 MPa, in the range of about 50 MPa to about 300 MPa, in the range of about 100 MPa to about 300 MPa, in the range of about 150 MPa to about 300 MPa, in the range of about 200 MPa to about 300 MPa, in the range of about 250 MPa to about 300 MPa, in the range of about 5 MPa to about 250 MPa, for example in the range of about 10 MPa to about 250 MPa, in the range of about 50 MPa to about 250 MPa, in the range of about 100 MPa to about 250 MPa, in the range of about 150 MPa to about 250 MPa, in the range of about 200 MPa to about 250 MPa, in the range of about 5 MPa to about 200 MPa, for example in the range of about 10 MPa to about 200 MPa, in the range of about 50 MPa to about 200 MPa, in the range of about 100 MPa to about 200 MPa, in the range of about 150 MPa to about 200 MPa, in the range of about 5 MPa to about 150 MPa, for example in the range of about 10 MPa to about 150 MPa, in the range of about 50 MPa to about 150 MPa, in the range of about 100 MPa to about 150 MPa, in the range of about 5 MPa to about 100 MPa, for example in the range of about 10 MPa to about 100 MPa, in the range of about 50 MPa to about 100 MPa, in the range of about 5 MPa to about 50 MPa, for example in the range of about 10 MPa to about 50 MPa, or in the range of about 5 MPa to about 10 MPa.

[0064] In some embodiments, producing a recycled material pellet may comprise compacting the shredded glass fiber waste material at a pressure at least above about 50 MPa and up to about 400 MPa, for example at least about 75 MPa, at least about 125 MPa, or at least about 175 MPa.

[0065] In embodiments, at least 60 wt.% of the glass fibers in the recycled material pellet have a fiber length in the range of about 0.5 mm to about 20 mm, for example at least 60 wt.% of the glass fibers have a fiber length in the range of about 0.5 mm to about 15 mm, in the range of about 0.5 mm to about 12.5 mm, in the range of about 0.5 mm to about 10 mm, in the range of about 0.5 mm to about 7.5 mm, in the range of about 0.5 mm to about 5 mm, in the range of about 0.5 mm to about 2.5 mm, in the range of about 1 to 20 mm, in the range of about 1 mm to about 15 mm, in the range of about 1 mm to about 12.5 mm, in the range of about 1 mm to about 10 mm, in the range of about 1 mm to about 7.5 mm, in the range of about 1 mm to about 5 mm, in the range of about 1 mm to about 2.5 mm, in the range of about 2.5 mm to about 20 mm, in the range of about

[0066] 2.5 mm to about 15 mm, in the range of about 2.5 mm to about 12.5 mm, in the range of about

[0067] 2.5 mm to about 10 mm, in the range of about 2.5 mm to about 7.5 mm, in the range of about 2.5 mm to about 5 mm, in the range of about 5 mm to about 20 mm, in the range of about 5 mm to about 15 mm, in the range of about 5 mm to about 10 mm, in the range of about 5 mm to about

[0068] 7.5 mm, in the range of about 7.5 mm to about 20 mm, in the range of about 7.5 mm to about 15 mm, in the range of about 7.5 mm to about 12.5 mm, in the range of about 7.5 mm to about 10 mm, in the range of about 10 mm to about 20 mm, in the range of about 10 mm to about 15 mm, in the range of about 10 mm to about 12.5 mm, in the range of about 12.5 mm to about 20 mm, in the range of about 12.5 mm to about 15 mm or in the range of about 15 mm to about 20 mm. The fiber length of the glass fibers may be measured using microscopic analysis, for example microscopic analysis of the glass fibers after burning the pellet to remove the binder.

[0069] In embodiments, prior to compacting, the glass fibers and thermoplastic binder are shredded. For example, the glass fibers and thermoplastic binder may be shredded by any shredding technique known in the art.

[0070] In embodiments, compacting the composition to form a recycled material pellet comprises heating the composition at a temperature of at least about 30 °C, for example at least about 40 °C, at least about 50 °C, at least about 60 °C, at least about 70 °C, at least about 80 °C, at least about 90 °C, or at least about 100 °C. In embodiments, compacting the composition to form a recycled material pellet further comprises heating the composition at a temperature of at least about 30 °C, for example at least about 40 °C, at least about 50 °C, or at least about 60 °C. In embodiments, compacting the composition to form a recycled material pellet further comprises heating the composition at a temperature of up to about 100 °C, for example up to about 80 °C, up to about 70 °C, or up to about 60 °C. In embodiments, compacting the composition to form a recycled material pellet further comprises heating the composition at a temperature in the range of about 40 °C to about 70 °C, for example in the range of about 50 °C to about 70 °C, or at least about 100 °C. In embodiments, compacting the composition to form a recycled material pellet comprises heating the composition at a temperature of about 60 °C. In embodiments, compacting the composition to form a recycled material pellet comprises heating the composition at a temperature in the range of about 30 °C to about 100 °C, for example about 40 °C to about 80 °C, or about 50 °C to about 70 °C. In embodiments, the glass fibers and thermoplastic binder are sourced from non-woven veils or composite materials comprising non-woven veils.

[0071] The term "non-woven veil" is commonly used to describe a lightweight glass fiber material (areal weight in the range of about 10 to about 200 g / m2, for example about 20 to about 150 g / m2, or about 20 to about 100 g / m2) composed of randomly oriented glass fibers, a binder and optionally fillers. The veil may be formed by a wet-laid process. The non-woven veil may be recycled nonwoven veil. For example, sourced from ceiling, floor or wall boards.

[0072] In embodiments, the compacting is achieved using any one of: a pellet mill; a mechanical screw press; a piston press; a roller pressure; a tablet press; a tumbling granulator; a mixer granulator; biomass compaction; densification under vacuum; or a combination thereof.

[0073] Examples

[0074] The following illustrates an example of the recycled material pellet and related aspects described herein. Thus, these examples should not be considered to restrict the present disclosure, but are merely in place to teach how to carry out the processes and obtain the products of the present disclosure.

[0075] Examples 1 to 9

[0076] The inventors carried out a study to establish the importance of having thermoplastic binder present in the shredded glass fiber waste material.

[0077] The inventors used eight different glass fiber waste materials. Two of the glass fiber waste material contained glass fibers and thermoplastic binder. Six of the glass fiber waste materials contained glass fibers and thermosetting binder. One of these glass fiber waste materials also contained a thermoplastic stitching yarn, the total amount of thermoplastic in the glass fiber waste material was less than 2 wt.% (about 1 wt.%).

[0078] All of the glass fiber waste material was provided shredded. Each shredded composition was compacted, under the same conditions, by a Mandoka Pellet Mill.

[0079] Shredded Glass Fiber Waste Material Used in Examples 1 to 8:

[0080] Example 1: WUCS (Wet Use Chopped Strand) contains glass fibers, water and thermoset binder. The material used contains 92.7 wt.% of glass fibers, 0.3 wt.% of thermoset binder and 7 wt.% of water.

[0081] Example 2: Dry WUCS (Dry Wet Use Chopped Stand) contains glass fibers, thermoset binder. The material used contains 99.7 wt.% of glass fibers, 0.3 wt.% of thermoset binder.

[0082] Example 3: Shredded UD fabric (Unidirectional) contains glass fibers, thermoset binder and a thermoplastic stitching yarn. The material used contains 98.5 % wt. of glass fibers, 0.5 % wt. of thermoset binder and about 1 wt.% of thermoplastic polyester stitching yarn.

[0083] Example 4: Shredded Cake Hulls contains glass fibers and thermoset binder. The material used contains 98 wt.% of glass fibers and 2 wt.% of thermoset binder.

[0084] Example 5: Shredded CFM (Continuous Filament Mat) contains glass fibers and thermoset binder. The material used contains 96 wt.% of glass fibers and 4 wt.% of thermoset binder. Example 6: Shredded CSM (Chopped Strand Mat) contains glass fibers and thermoplastic binder. The material used contains 96 wt.% of glass fibers and 4 wt.% of thermoplastic binder.

[0085] Example 7: Dry Use Chopped Strand contains glass fibers and thermoset binder. The material used contains 99 wt.% of glass fibers and 1 wt.% of thermoset binder.

[0086] Example 8: Shredded NW fabric (Non-Woven) contains glass fibers and thermoplastic binder. The material used contains 80 wt.% of glass fibers and 20 wt.% of thermoplastic binder.

[0087] As shown below in Table 1, the shredded glass fiber waste materials with thermoplastic binder had good processability and formed pellets. The shredded glass fiber waste materials with no thermoplastic binder did not form pellets. In some cases, powder was formed but no pellets. The inventors have found that the thermoplastic binder is required to remarkably improve pelletisation. Although these results show that thermoplastic binder within the glass fiber waste material is important, thermoplastic binder may be added to a glass fiber waste material with no intrinsic thermoplastic binder.

[0088] A pellet as defined in the table below comprises a density of at least about 150 kg / m3and a diameter of at least 2 mm.

[0089] Table 1

[0090] Example 9

[0091] A recycled material pellet was produced by providing a glass fiber waste material. The glass fiber waste material was non-woven veil. The non-woven veil comprised glass fibers and a thermoplastic binder. The non-woven veil was shredded. The shredded non-woven veil had a density of 100 kg / m3. The shredded non-woven flooring veil of glass fibers and thermoplastic binder were compacted by a Mandoka Pellet Mill to form a pellet. The resultant recycled material pellet had a diameter of 6 mm and a density of 800 kg / m3.

[0092] Figure 1 shows a photograph of the shredded non-woven veil having a density of 100 kg / m3used in Example 9.

[0093] Figure 2 shows a photograph of the resultant recycled material pellet having a density of 800 kg / m3formed in Example 9.

[0094] The present inventors have found that the provision of such recycled material pellets improves the flowability of shredded glass fiber waste material comprising glass fibers and thermoplastic binder. The recycled material pellet has an increased density in comparison to the shredded nonwoven flooring veil. Alongside increased density, the present inventors found a reduced amount of dust compared to the shredded shredded non-woven flooring veil. The overall ease of handling of these materials was improved.

[0095] Therefore, the present inventors have discovered that compacting a shredded glass fiber waste material comprising glass fibers and thermoplastic binder improves the handling and dosing glass fiber composite materials. The present inventors found that the provision of a recycled material pellet allows for the reuse of high value materials from glass fiber composite materials. This may be particularly advantageous for large scale use.

[0096] Equipment used in Examples Mandoka Pellet Mill - The composition was introduced on an inner side of a die within the pellet mill. Spreaders are present in the pellet mill to evenly distribute the composition. As the die rotates, a roller compresses the composition through holes in the die. A cutter flush with the outer side of the die cuts the exposed recycled material pellet free from the die.

[0097] Measurement Methods used in the Examples

[0098] Integrity of the Pellets

[0099] To measure the integrity of the pellets, the pellets are subjected to circulation by means of compressed air in a circular metal corridor.

[0100] This test simulates what the pellets undergo when they are pneumatically transported on the extrusion lines between the storage location and the extruder.

[0101] The following steps describe the integrity test:

[0102] 1) Samples are weighed.

[0103] 2) Samples are placed in a circular metal container.

[0104] 3) Compressed air is introduced into the container.

[0105] 4) After a set amount of time, the compressed air is stopped.

[0106] 5) The samples are removed from the container and sieved through a sieve.

[0107] 6) The parts of the samples that pass through the sieve are collected. These parts form a mat.

[0108] 7) The weight of the mat is compared to the original weight of the samples to establish the loss rate.

[0109] The sieve perforations have a diameter of 4 mm.

[0110] The integrity of the pellets produced according to Example 9 was measured using the abovedescribed method.

[0111] The first test carried out employed compressed air at a pressure of 0.25 MPa, a test time of 1 min and used 50g of pellets. The loss rate was found to be 4.6 g / kg.

[0112] The second test carried out employed compressed air at a pressure of 0.4 MPa, a test time of 2 min and used 150g of pellets. The loss rate was found to be 7.3 g / kg.

[0113] The determined loss rates show that the pellets produced in Example 9 have good handleability. Density

[0114] The apparent bulk density of the shredded glass fiber waste material was determined using standard apparent bulk density methodology. The mass of 1 litre of shredded glass fiber waste material was measured, and used to determine the density of the shredded glass fiber waste material.

[0115] The apparent bulk density of the recycled material pellet was determined using determined using standard apparent bulk density methodology. The mass of 1 litre of recycled material pellets was measured, and used to determine the density of the pellets.

[0116] The density measurements were all performed at standard room temperature.

[0117] The inventors expect that a shredded glass fiber waste material comprising other amounts of glass fibers and thermoplastic binder, for example a composition comprising glass fibers and a thermoplastic binder, the thermoplastic binder constituting within the range of 2 wt.% to 30 wt.% is thought to provide recycled material pellets with similar advantages to the composition employed in the above Example.

[0118] The inventors expect that a lower density such as about 250 kg / m3may improve retention of glass fiber length and thus mechanical properties of the glass fibers. The inventors expect a higher density such as about 700 kg / m3may improve the ease of handling of the composition of shredded glass fiber waste material, and may reduce the loss rate.

[0119] Further studies were conducted by the present inventors, recycled material pellets with a higher density, for example 0.97 g / m3compared to 0.70 g / m3, were found to be more resistant to pneumatic transport as they displayed higher structural integrity and resulted in no loss during testing using the above method. Such recycled material pellets may be made using the pellet mill method described above.

[0120] The present inventors conducted further studies investigating the influence of temperature on integrity of the recycled material pellets. The present inventors used the same compacted shredded glass fiber waste material to produce two sets of pellets. One set of pellets was made using an 18 mm dye at a temperature of 40 °C. The other set of pellets was made using an 18 mm dye at a temperature of 60 °C. The present inventors found that the pellets formed at a temperature of 60 °C were more resistant to pneumatic transport as they displayed higher structural integrity, when tested using the above method. The pellets may be manufactured using the pellet mill method described above.

[0121] The present inventors consider that further advantages in relation to structural integrity of the pellets produced may be provided by using glass fiber waste material consisting of thermoplastic binder and glass fibers as described herein. Studies carried out by the present inventors suggest that using glass fiber waste material consisting of thermoplastic binder and glass fibers as described herein provides pellets with improved structural integrity for a given amount of thermoplastic binder compared to pellets formed from glass fiber waste material comprising glass fibers, thermoplastic binders and fillers.

[0122] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

[0123] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

[0124] For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.

[0125] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0126] Throughout this specification, including the claims which follow, unless the context requires otherwise, the word "comprise" and "include", and variations such as "comprises", "comprising", and "including" will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0127] It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" in relation to a numerical value is optional and means for example + / - 10%.

Claims

CLAIMS1. A recycled material pellet comprising: compacted shredded glass fiber waste material comprising glass fibers and a thermoplastic binder; wherein the thermoplastic binder constitutes at least about 2 wt.% of the recycled material pellet.

2. A recycled material pellet according to claim 1, wherein the shredded glass fiber waste material constitutes at least 90 wt.% of the recycled material pellet.

3. A recycled material pellet according to any one of the preceding claims, wherein the thermoplastic binder constitutes up to about 30 wt.% of the recycled material pellet and wherein the glass fibers constitute at least 25 wt.% of the recycled material pellet.

4. A recycled material pellet according to any one of the preceding claims, wherein the thermoplastic binder constitutes in the range of about 2 wt.% to about 25 wt.% of the recycled material pellet.

5. A recycled material pellet according to any one of the preceding claims, having a density within the range of about 150 kg / m3to about 1000 kg / m3.

6. A recycled material pellet according to claim 5, having a density within the range of about 300 kg / m3to about 800 kg / m3.

7. A recycled material pellet according to any one of the preceding claims, wherein the glass fibers have an aspect ratio of at least 5:1.

8. A recycled material pellet according to any one of the preceding claims, wherein the thermoplastic binder has a glass transition temperature in the range of about 30 °C to about 80 °C.

9. A recycled material pellet according to any one of the preceding claims, having a diameter in the range of about 2 to about 10 mm.

10. A recycled material pellet according to any one of the preceding claims, having a length in the range of about 1 to about 50 mm.

11. A recycled material pellet according to any of the preceding claims, wherein the glass fibers have a fiber length of at least about 0.5 mm.

12. A recycled material pellet according to any of the preceding claims, wherein the recycled material pellet consists of: compacted shredded glass fiber waste material consisting of glass fibers and a thermoplastic binder; wherein the thermoplastic binder constitutes at least about 2 wt.% of the recycled material pellet.

13. A method of producing a recycled material pellet, the method comprising: providing a shredded glass fiber waste material comprising glass fibers and a thermoplastic binder, the thermoplastic binder constituting at least about 2 wt.% of the shredded glass fiber waste material; and compacting the shredded glass fiber waste material to form a recycled material pellet.

14. A method of producing a recycled material pellet according to claim 13, wherein compacting the shredded glass fiber waste material forms a recycled material pellet having a density within the range of about 150 kg / m3to about 1000 kg / m3.

15. A method of producing a recycled material pellet according claims 13 or 14, wherein compacting the shredded glass fiber waste material is carried out at a temperature in the range of about 50 °C to about 70 °C.

16. A recycled material pellet product produced according to the method of claims 13 to 15.

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