FLAME RETARDANT FABRICS

Abstract

A fire retardant fabric includes a base fabric and expandable graphite particles secured to a surface of and/or embedded in the base fabric. The expandable graphite particles may be bonded or otherwise secured to the base fabric with an adhesive material. The fire retardant fabric may optionally include a web material over a surface of the base fabric to which the expandable graphite particles have been applied. Methods for manufacturing such a fire retardant fabric are also disclosed. Such a method may include applying expandable graphite particles and an adhesive material to a base fabric and, with the adhesive material, bonding or otherwise securing the expandable graphite particles to the base fabric.

Claims

1. A method for applying a fire retardant material to a fabric, comprising: mixing expandable graphite particles and adhesive particles together to form a homogenous mixture; evenly applying the homogenous mixture to a surface of a base fabric; and heating the homogenous mixture to bond the adhesive particles to adjacent expandable graphite particles and to the base fabric.

2. The method of claim 1, wherein mixing the expandable graphite particles and the adhesive particles together comprises mixing the expandable graphite particles with adhesive particles comprising an ethylene vinyl acetate (EVA).

3. The method of claim 1, wherein mixing the expandable graphite particles and the adhesive particles together comprises mixing the expandable graphite particles with adhesive particles comprising a thermoplastic polyurethane (TPU).

4. The method of claim 1, further comprising: preheating the base fabric before evenly applying the homogenous mixture to the surface of the fabric.

5. The method of claim 1, wherein evenly applying the homogenous mixture comprises powder scattering the homogenous mixture over the surface of the base fabric.

6. The method of claim 1, wherein evenly applying comprises positioning a transfer sheet carrying a layer of the homogenous mixture to the surface of the base fabric.

7. The method of claim 1, wherein heating the homogenous mixture includes applying pressure to the homogenous mixture.

8. A method for applying a thermally conductive material to a fabric, comprising: mixing expandable graphite particles comprising expandable graphite and adhesive particles comprising ethylene vinyl acetate and/or thermoplastic polyurethane together to form a homogenous mixture; evenly applying the homogenous mixture to a surface of a base fabric; and heating and applying pressure to the homogenous mixture to bond the adhesive particles and adjacent expandable graphite particles to the base fabric.

9. The method of claim 8, wherein evenly applying the homogenous mixture comprises powder scattering the homogenous mixture over the surface of the base fabric.

10. The method of claim 8, wherein evenly applying comprises positioning a transfer sheet carrying a layer of the homogenous mixture to the surface of the base fabric.

11. The method of claim 8, further comprising: applying a web material to the homogenous mixture on the surface of the base fabric.

12. A fire retardant fabric, comprising: a base fabric including a lower surface and an outer surface; expandable graphite particles homogenously distributed over the lower surface of the base fabric; and an adhesive material bonded to the expandable graphite particles and to the lower surface of the base fabric to bond the expandable graphite particles to the base fabric.

13. The fire retardant fabric of claim 12, wherein the base fabric comprises polyester.

14. The fire retardant fabric of claim 12, wherein the adhesive material comprises ethylene vinyl acetate (EVA) or a thermoplastic polyurethane (TPU).

15. The fire retardant fabric of claim 12, having substantially a same hand feel and drape as the fabric prior to application of the expandable graphite particles and the adhesive material thereto.

16. The fire retardant fabric of claim 12, further comprising: a web material over the expandable graphite particles, the adhesive material, and the lower surface of the fabric.

17. The fire retardant fabric of claim 16, wherein the web material comprises an adhesive material.

18. The fire retardant fabric of claim 16, wherein the web material comprises polyester, polyamide, polypropylene, or polyethylene.

19. The fire retardant fabric of claim 16, wherein the web material has a weight of about 5 g/m.sup.2 to about 200 g/m.sup.2.

20. The fire retardant fabric of claim 16, wherein the web material is an ultra light fabric.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In the drawings,

[0026] FIG. 1 illustrates an embodiment of a fire retardant fabric of this disclosure;

[0027] FIG. 2 illustrates another embodiment of a fire retardant fabric of this disclosure; and

[0028] FIG. 3 is a schematic representation of an apparatus for forming a fire retardant fabric of this disclosure.

DETAILED DESCRIPTION

[0029] As illustrated by FIG. 1, a fire retardant fabric 10 includes a base fabric 20, expandable graphite particles 30, and an adhesive material 40. The expandable graphite particles 30 may reside on a surface of the base fabric 20 and/or extend into the base fabric 20. The adhesive material 40 may secure the expandable graphite particles 30 to the base fabric 20.

[0030] The base fabric 20 may comprise any suitable or desired fabric. Without limitation, the base fabric 20 may comprise a conventional fabric (i.e., an unenhanced fabric) that has low thermal conductivity, such as a polyester fabric, a low-density polyethylene (LDPE) fabric, or the like. As another example, the base fabric 20 may comprise a conventional fabric (i.e., an unenhanced fabric) with some thermal conductivity. As yet another example, the base fabric 20 may comprise a fabric that has been made with a thermal conductivity-enhancing technology (e.g., a conventional thermal conductivity-enhancing technology, another thermal conductivity-enhancing technology, etc.). The base fabric 20 may be of any desired composition (e.g., it may include synthetic fibers, synthetic fiber blends, natural fibers, natural fiber blends, blends of natural and synthetic fibers, etc.).

[0031] The base fabric 20 may have any desired weight (e.g., it may be ultra light (i.e. less than 100 g/m.sup.2), lightweight (i.e., 100 g/m.sup.2 to 170 g/m.sup.2), midweight (i.e., 170 g/m.sup.2 to 340 g/m.sup.2), heavyweight (i.e., 340 g/m.sup.2 to 400 g/m.sup.2), or ultra heavy (i.e., more than 400 g/m.sup.2).

[0032] Graphite is a crystalline form of carbon in which carbon atoms are arranged in a hexagonal pattern, forming layers that are loosely bonded together. Expandable graphite is a form of intercalated graphite that can undergo significant expansion when exposed to heat (e.g., to temperatures of about 200 C. or more). This expansion increases the surface area of the graphite, which in turn can enhance its ability to provide a thermally insulative barrier.

[0033] The expandable graphite particles 30 may be dispersed across the base fabric 20 in such a way that the expandable graphite particles 30 are spaced apart from each other. Alternatively, the expandable graphite particles 30 may substantially cover the base fabric 20; for example, adjacent expandable graphite particles 30 may contact each other. The expandable graphite particles 30 may be substantially evenly dispersed across the base fabric 20 or the expandable graphite particles 30 may be evenly dispersed across the base fabric 20. Substantially even or even distribution of the expandable graphite particles 30 may maximize the surface area of the fire retardant fabric 10 that is fire resistant or fire retardant.

[0034] At least some of the expandable graphite particles 30 may be carried by a surface 22 of the base fabric 20. At least some of the expandable graphite particles 30 may extend into the base fabric 20 (e.g., into spaces between yarns from which the base fabric 20 is formed (e.g., knit, woven, etc.), etc.).

[0035] The adhesive material 40 adheres, secures, or bonds the expandable graphite particles 30 to the base fabric 20. The adhesive material 40 may comprise a thermoplastic material. The thermoplastic material may adhere to a surface of the base fabric 20. In some embodiments, the thermoplastic material may extend (e.g., wick, bleed, seep, etc.) into the base fabric 20 (e.g., into spaces between yarns from which the base fabric 20 is formed (e.g., knit, woven, etc.), etc.). The thermoplastic material 40 may comprise an EVA, a TPU, or the like. A specific but nonlimiting example of a suitable EVA is an EVA 2048 powder with a particle size of about 100 m to about 500 m. A specific but nonlimiting example of a suitable TPU is TPU 4073, which is a high performance TPU. Alternatively, the adhesive material 40 may comprise another suitable type of material that will adhere, secure, or bond the expandable graphite particles 30 to the base fabric 20.

[0036] The adhesive material 40 may define a film or layer 42 on a surface 22 of the base fabric 20. The film or layer 42 may be confluent (i.e., cover the entire surface 22 of the base fabric) or nonconfluent (i.e., it may include regions of the adhesive material 40 that are spaced apart from each other).

[0037] Addition of the expandable graphite particles 30 and adhesive material 40 to the base fabric 20 provides a fire retardant fabric 10 that may substantially maintain the other properties of the base fabric 20 (e.g., its feel, its drape, its stretchability, its durability, its breathability, etc.).

[0038] Optionally, as illustrated by FIG. 2, a fire retardant fabric 10 may include a base fabric 20, expandable graphite particles 30, and an adhesive material 40, as described in reference to the fire retardant fabric 10 shown in FIG. 1, as well as a web material 50 superimposed with the base fabric 20 and positioned over the surface 22 that carries the expandable graphite particles 30.

[0039] The web material 50 may be ultra light (i.e., less than 100 g/m.sup.2), lightweight (i.e., 100 g/m.sup.2 to 170 g/m.sup.2) or midweight (i.e., 170 g/m.sup.2 to 340 g/m.sup.2). The web material may have a weight of about 5 g/m.sup.2 to about 200 g/m.sup.2. The web material 50 may have a weight that is less than a weight of the base fabric 20. In some embodiments, a weight of the web material 50 may not add significantly to a weight of the base fabric 20. The combined weights of the base fabric 20 and the web material 50 may be in the same weight range as the base fabric 20 alone (e.g., ultra light, lightweight, midweight, heavyweight, etc.).

[0040] The web material 50 may comprise polyester, polyamide, polypropylene, or polyethelene. Such web material may be secured in place with the adhesive material. Alternatively, the web material may comprise or carry the adhesive material and, thus, secure itself and the expandable graphite particles 30 in place.

[0041] Addition of the expandable graphite particles 30, adhesive material 40, and web material 50 to the base fabric 20 provides a fire retardant fabric 10 that may substantially maintain the other properties of the base fabric 20 (e.g., its feel, its drape, etc.).

[0042] Turning now to FIG. 3, an embodiment of an apparatus 100 for forming a fire retardant fabric 10, 10 (FIGS. 1 and 2, respectively) of this disclosure is depicted. The apparatus 100 includes a feeder 110, an applicator 120, a bonder 130, and a collector 160. The apparatus 100 may optionally include a source 140 of web material 50 (FIG. 2).

[0043] The feeder 110 may include a source 112 for a base fabric 20 (FIGS. 1 and 2). The feeder 110 may include one or more motors 114 and pulleys 116 that convey the base fabric 20 into the apparatus 100 under a desired tension and convey the base fabric 20 through the apparatus 100 at a desired rate. The feeder 100 may optionally include one or more static eliminators 118 that remove static electricity from the base fabric 20 as it is conveyed into and through the apparatus 100.

[0044] Initially, the feeder 110 may convey the base fabric 20 into the applicator 120. The applicator 120 may include a source 122 for the conductive particles 30 and adhesive material 40. The applicator 120 may apply the expandable graphite particles 30 and adhesive material 40 to the base fabric 20 in any suitable manner. For example, as illustrated, the source 122 may be associated with a powder scatterer 124, which may dispense a mixture of the expandable graphite particles 30 and particles of the adhesive material 40 onto the base fabric 20 as the base fabric 20 is conveyed through the applicator 120. Alternatively, such a powder scatterer 124 may dispense adhesive material 40-coated expandable graphite particles 30 onto the base fabric 20 as the base fabric 20 is conveyed through the applicator 120. As an alternative to the illustrated source 122 and powder scatterer 124, the apparatus 100 may comprise a source (e.g., a roll, etc.) of a transfer sheet (e.g., a strip, a band, etc.; a transfer paper, etc.) to which the expandable graphite particles 30 and adhesive material 40 have been pre-applied (e.g., scattered onto, printed onto, etc.), and the transfer sheet may transfer the expandable graphite particles 30 and adhesive material 40 to the base fabric 20. In embodiments where a web material 50 is to be applied to the base fabric 20, the powder scatterer 124 may dispense the expandable graphite particles 30 but not any adhesive material 40.

[0045] Optionally, the applicator 120 may include one or more heaters 126, 128. For example, a heater 126 may preheat the base fabric 20 as it enters the applicator 120 and before the expandable graphite particles 30 and adhesive material 40 are applied to the base fabric 20. Such a heater 126 may preheat the base fabric 20 to a temperature that will heat the adhesive material 40 to a sufficient temperature to enable it to adhere to the base fabric 20 and the expandable graphite particles 30. As another example, a heater 128 may heat the base fabric 20 after the expandable graphite particles 30 and adhesive material 40 have been applied to it to enable the adhesive material 40 to adhere to the base fabric 20 and to the expandable graphite particles 30 and or to evaporate, or drive, any moisture from the base fabric 20, expandable graphite particles 30, and adhesive material 40. With the expandable graphite particles 30 and adhesive material 40 on the base fabric 20, any transfer sheet may be removed from the base fabric 20.

[0046] From the applicator 120, the feeder 110 may convey the base fabric 20, conductive particles 30, and any adhesive material 40 to the bonder 130. In embodiments where the apparatus 100 includes a source 140 of web material 50, the feeder 110 may also convey the web material 50 to the bonder 130. The bonder 130 may bond the conductive particles 30 and the web material 50, if any, to the base fabric 20. More specifically, the bonder 130 may cause or enable the adhesive material 40 and/or the web material 50 to bond the conductive particles 30 and the optional web material 50 to the base fabric 20.

[0047] The bonder 130 may include a conveyor 132 with a drum 133 (e.g., a Teflon coated drum, etc.) and a series of rollers 134 that carry and move a belt 135 (e.g., silicone coated felt, etc.) past a pressure roller 136. The belt 135 may carry the base fabric 20 and the optional web material 50 through the bonder 130 to enable the bonder 130 (e.g., the pressure roller 136, etc.) to apply heat and/or pressure to the adhesive material 40 and/or any web material 50 to at least partially melt the adhesive material 40 and/or any web material 50 and enable it/them to secure the expandable graphite particles 30 and the optional web material 50 to the base fabric 20. The result is a fire retardant fabric 10 (FIGS. 1 and 2).

[0048] From the bonder 130, the feeder 110 may conveys the fire retardant fabric 10 past an optional cutter 150. The cutter 150 may comprise any suitable cutter for fabric. Without limitation, the cutter 150 may comprise a crush cutter.

[0049] The fire retardant fabric 10 is ultimately conveyed to a collector 160. The collector 160 may comprise one or more reels 162, which may receive and roll the fire retardant fabric 10. Alternatively or additionally, the collector 160 may comprise a folder 164 folds and/or stacks the fire retardant fabric 10.

[0050] With returned reference to FIGS. 1 and 2, in normal use, the expandable graphite particles 30 of a fire retardant fabric 10, 10 of this disclosure may convey heat away from an individual. If the fire retardant fabric 10, 10 is subjected to a sufficient temperature (e.g., 140 C. to 230 C., about 200 C. or more, etc.), as may occur when the fire retardant fabric 10, 10 is exposed to a heater, a heated tool (e.g., an iron, a heated hairstyling tool, etc.), hot coals, cigarette or cigar ash, a flame, or the like, the expandable graphite particles 30 may expand, which may prevent ignition of the flame retardant fabric 10, 10 or limit the extent to which the flame retardant fabric 10, 10 ignites.

[0051] Although the disclosure provides many specifics, the specifics should not be construed as limiting the scope of any of the claims, but merely as providing illustrations of some embodiments of elements and features of the disclosed subject matter that fall within the scopes of the claims. Other embodiments of the disclosed subject matter may be devised that are also within the scopes of the claims. Accordingly, the scope of each claim is limited only by its plain language and the legal equivalents thereto.