US20220002920A1

US20220002920A1 - Flame resistant fabric

Info

Publication number: US20220002920A1
Application number: US17/363,934
Authority: US
Inventors: Terry Godusky; Michael Hartman
Original assignee: Front Line Fabrics Inc
Current assignee: Front Line Fabrics Inc
Priority date: 2020-07-01
Filing date: 2021-06-30
Publication date: 2022-01-06

Abstract

A flame resistant fabric is disclosed herein. The fabric comprising blended yarns consists of: 40%-60% inherently flame resistant fibers, 20%-60% non-flame resistant cellulose fibers, and 5%-30% flame resistant aramid structural fibers. The fabric is evaluated by at least the following test methods: ASTM D6413; ASTM F1959; ASTM D3786; AATCC 61 Method A; AATCC 135; ASTM F2700; ASTM 1930; and ASTM 2894. The fabric also meets the ASTM 1506-19a and NFPA 2112-2018 test standard.

Description

INCORPORATION BY REFERENCE

This application claims the benefit of U.S. Provisional Application No. 63/046,933, filed on Jul. 1, 2020, which is incorporated by reference as if fully set forth herein.

FIELD OF INVENTION

The present disclosure relates to a fabric, and more particularly relates to a flame resistant fabric.

BACKGROUND

Flame resistant clothing is worn by many workers in fire services, manufacturing industries, public utility industries, oil and gas industries, and other industries that may be exposed to electric arc or flash fire. Workers can also be exposed to weather related environmental conditions that require single layer for warm weather comfort or multi-layer clothing and uniforms for cold weather and warmth.
Clothing used in these industries are typically manufactured using flame resistant fabrics that will self-extinguish and protect the worker from severe injury. These fabrics consist of various fiber combinations and knit constructions designed to achieve specific arc ratings and flash fire ratings based upon specific industry standards. An example of one such fabric is disclosed in U.S. Pat. No. 7,678,718.
However, known fabrics in these fields tend to be greater than 6.0 ounces per square yard, and are cumbersome and heavy, which causes discomfort for the user. It would be desirable to provide a reliable fabric that meets all of the requisite tests to be flash fire and arc resistant, that also improves comfort for the user.

SUMMARY

A flame resistant knitted fabric is disclosed herein that provides flash fire and arc rated protection, as well as aids in the regulation of a user's body temperature. The fabric manages a user's microclimate and body temperature by helping to wick moisture away from the user's skin.
In one embodiment, the inherently flame resistant fibers include modacrylic, the non-flame resistant cellulose fibers include cotton or lyocell, and the flame resistant aramid fibers include para-aramids or meta-aramids.
In one embodiment, a weight of the fabric is between 4.5 ounces per square yard and 10.0 ounces per square yard. The fabric can be formed from yarns having counts between 20/1 c.c. and 40/1 c.c. or equivalent weight plied yarns.
The fabric can have a double knit circular configuration. In another embodiment, the fabric is formed as a single or plied count yarn.
The fabric disclosed herein is evaluated by meets the following testing methods and meets at least the following standards: ASTM D6413; ASTM F1959; ASTM D3786; AATCC 61 Method A; AATCC 135; ASTM F2700; ASTM 1930; and ASTM 2894. The fabric also meets the requirements under both NFPA 2112-2018 and ASTM 1506 Standards.
In one embodiment, the fabric is treated with at least one of: an anti-microbial solution, or a softener.
Structurally, the fabric includes a flat channeled front surface and a rear surface including air-trapping pockets.
The yarns and knit construction are configured to promote phobic and philic interactions to wick moisture away from a user.
In one embodiment, the fabric is formed with a knit configuration having a four feed repeat configuration in which every other needle is removed.
The fabric is knit in tubular form, in one aspect.
Regarding further processing, the fabric can be dyed to color. The dyeing temperature is preferably less than 220° F.
In terms of forming the fabric, a circular knitting machine with an approximately 20 inch-34 inch cylinder diameter and approximately 600-2200 needle positions is used.
Additional embodiments are disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing Summary and the following Detailed Description will be better understood when read in conjunction with the appended drawings, which illustrate a preferred embodiment of the disclosure. In the drawings:

FIG. 1 is a schematic of a knit configuration for a fabric according to one embodiment.

FIG. 2A illustrates a channel side stitching pattern according to one embodiment.

FIG. 2B illustrates a pocket side stitching pattern according to one embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Certain terminology is used in the following description for convenience only and is not limiting. “Axially” refers to a direction along an axis (X) of an assembly. “Radially” refers to a direction inward and outward from the axis (X) of the assembly. “Circumferentially” refers to a direction extending along a curve or circumference of a respective element relative to the axis (X) of the assembly.
A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, or c, or combinations thereof. The terminology includes the words specifically noted above, derivatives thereof and words of similar import.
The present disclosure is directed to a fabric, as well as the yarns and yarn configuration to form the fabric. The present disclosure is also directed to the formation methods disclosed herein to form the fabric and yarns.
The fabric disclosed herein is formed via a unique combination of intimately blended fibers and a specific knitting pattern. The blend of fibers creates phobic and philic interactions that grab and wick moisture (such as perspiration), and transports the moisture away from a user's skin to promote evaporation.
The knit construction creates a structure including air-entrapping pockets to provide warming benefits when layered with another garment to maintain body heat. In other words, the fabric provides a greater clo value. In a non-layered arrangement, the fabric provides air permeability to transfer moisture away from the user's skin and promote evaporation and cooling.
As shown in FIG. 1, a knit configuration is illustrated for the fabric according to one embodiment. The knit configuration is a four feed repeat configuration in which every odd needle is removed and around the circumference of the machine.
In one aspect, Feed 1 includes both cylinder and dial needles forming a knit stitch on both the face and back of the fabric (i.e. inside and outside). Feed 2 is identical to Feed 1. Regarding Feed 3, the cylinder needle knits and the dial needle tucks, which forms a pocket in the fabric. Feed 4 is identical to Feed 3. One of ordinary skill in the art would understand that the configurations for Feeds 1, 2, 3, and/or 4 can be modified depending on the specific requirements for a particular application.
On the left-hand side of FIG. 1, the numbers 1, 2, 3, 4, and repeated numbers 1, 2, 3, and 4 are used to identify individual yarn feeds coming into the machine. In one aspect, FIG. 1 is provided to illustrate the settings on a machine for forming the fabric disclosed herein. More specifically, FIG. 1 illustrates the settings for a series of yarn feed positions for the cylinder and dial associated with a four feed repeat pattern.
In one aspect, a four feed repeat pattern is used in which every other needle removed is used to produce a fabric with a flat channeled face side and a back with pockets. This is shown in FIGS. 2A and 2B, which is described in more detail herein.
In one aspect, FIG. 2A illustrates a schematic of the pattern looking at the fabric's face. On the channel side shown in FIG. 2A, which also corresponds to the cylinder side, the removed needles form a vertical continuous channel. In FIG. 2A, the symbol “=” schematically represents an illustration of the deepest point in the channel when viewed from the fabric's face side on the inside fabric surface. The formation of the channel maximizes the bottom to top air flow when worn on the body. In FIGS. 2A and 2B, the rows of stitches and pockets are indicated as they would be viewed from the fabric's face and back.
In one aspect, FIG. 2B is a schematic of the pattern looking at the fabric's back. On the pocket side shown in FIG. 2B, which also corresponds to the dial side, the tuck stitch formulation of the rib construction forms a kidney shaped pocket (schematically represented by “O” in FIG. 2B) over the outside surface of the fabric. This pocket facilitates dual functionality depending on the single or multiple layer use.
Both sides of the fabric work together in the overall functionality and performance characteristics. The rib configuration on the channel side is the support of the fabric next to skin. The air flow within the channel allows air and vapor moisture movement up the body and regulation of the body temperature. In addition, the hydrophilic and hydrophobic nature of the yarns draw away moisture from the skin and transfer moisture to the pocket side of the fabric. The placement of the pockets and the porosity of the fabric construction allows the path from the channel side. This interaction provides two unique functions.
First, when worn as a single layer, the increased fabric surface area created by the pockets allows for the expedited evaporation of moisture. This feature aids in keeping the wearer dry, cool and comfortable. This aspect is important to the regulation of body temperature in warm environments.
Second, when worn as a layered configuration with another garment over top, the pockets trap air. Air having a low thermal transmission, provides the insulation that increases the clo value to keep the wearer warm in cold environments.
In one embodiment, a machine for forming the fabric, i.e. a knitting machine, includes a 20-34 inch cylinder diameter and 18 cut utilizing approximately 600-2200 needle positions. As used in this respect, the term cut is a measurement indicating the number of needle positions per inch. One of ordinary skill in the art would understand based on this disclosure that the cylinder can be larger or smaller, and the cut and needles can vary.
In one embodiment, the fabric is formed as a single count yarn. The fabric can be knit in tubular form, which is defined as greige fabric. The greige fabric can then be dyed and finished using a process that does not require any topical flame retardant treatments. The dye and finish process can include scouring the fabric to remove waxes and oils from the manufacturing process of the yarn and knitting.
Any suitable dying methods can be used to dye the fabric to the desired color. Dyeing can be applied to single or multiple fibers of the fabric. The dye temperatures are preferably controlled to a maximum temperature of 220° F.
After dyeing, the fabric is then dried and finished on frame. This process can include steaming and setting the fabric to a desired width. Rolls of finished fabric are then measured, weighed, and labeled.
The unique open knit constructions fabric promotes air permeability, moisture vapor transmission, vertical wicking, and stretch recovery.
The air-entrapping pockets promote higher clo value, resulting in warmth for the wearer. In this embodiment, the fabric is formed from an inner side and an outer side each including unique and separately formed surfaces in order to facilitate the improved clo value.
Regarding thermal equilibrium, the fabric allows the user's body to maintain a balanced temperature.
The yarn blends used to form the fabric, i.e. the fabric used for the Feeds in FIG. 1, can include intimately blended yarns of 40%-60% inherently flame resistant fibers, 20%-60% non-flame resistant cellulose fibers, and 5%-30% flame resistant aramid structural fibers. In one aspect, the non-flame resistant cellulose fibers comprise 40%-60% of the fabric. In one aspect, the fabric is formed from 45%-55% inherently flame resistant fibers, and 25%-35% non-flame resistant cellulose fibers, and 15%-25% flame resistant aramid structural fibers. In one aspect, the fabric is formed from 50% inherently flame resistant modacrylic fiber, and 30% non-flame resistant cellulose lyocell fiber, and 20% flame resistant aramid structural fiber. In one aspect, these values are approximate values, and include slight variations of 1%-10% of the stated values.
In one embodiment, the yarn blends forming the fabric consist only of the inherently flame resistant fibers, the non-flame resistant cellulose fibers, and the flame resistant aramid structural fibers. In another embodiment, additional secondary elements can be used to form the fabric.
In one embodiment, the inherently flame resistant fibers can include modacrylic, lyocell or cotton, and aramid. One of ordinary skill in the art would understand based on this disclosure that other inherently flame resistant fibers can be used.
In one embodiment, the non-flame resistant cellulose fibers can include cotton or lyocell. One of ordinary skill in the art would understand that other non-flame resistant cellulose fibers can be used.
In one embodiment, the flame resistant aramid fibers can include para-aramids or meta-aramids. One of ordinary skill in the art would understand based on this disclosure that other flame resistant aramid fibers can be used.
In one embodiment, the fabric weight is between 4.5 ounces per square yard and 10.0 ounces per square yard. The yarn used to form the fabric can include yarn counts between 20/1 c.c. and 40/1 c.c. or equivalent to achieve varied ounces per square yard of fabric.
Regarding the construction of the fabric, a double knit circular configuration is preferably used. The fabric has superior moisture management and air permeability. The fabric provides dual functionality as both a base layer thermal garment, and a cooling garment. Based on these characteristics, the fabric can be used in many industries, including oil and gas, public utilities, firefighting, manufacturing, etc.
In one embodiment, the fabric includes a double knit thermal regulator fabric having air-entrapping pockets.
In one embodiment, the fabric is further treated to improve its performance characteristics with secondary solutions or coatings. For example, the fabric can be treated with anti-microbial solutions or coatings, softeners, anti-static solutions or coatings, etc.
Flame Resistant Properties
The fabric meets the requirements under NFPA 2112-2018. The fabric disclosed herein is tested and meets the following test methods:
ASTM D6413 (Vertical Flammability (100 Wash));
ASTM F1959 (Arc Testing);
ASTM D3786 (Bursting Strength);
AATCC 61 Method A (Colorfastness);
AATCC 135 (Dimensional Change);
ASTM F2700 (Heat Transfer Performance);
ASTM 1930 Manikin Test;
ASTM 2894 (Heat and Thermal Shrinkage); and
Melt Drip.
The heat transfer performance of the fabric includes the following characteristics. The fabric does not exhibit less than 25 J/cm2 (6.0 cal/cm2) in a spaced test, and 12.6 J/cm2 (3.0 cal/cm2) in a contact test.
The fabric also meets the flame resistance requirements under ASTM D6413. Under these tests, the char length of the fabric is less than 100 mm and the afterflame is less than two seconds with no melting or dripping. The fabric exhibits these characteristics prior to and after 100 wash and dry cycles. Regarding thermal shrinkage, the fabric does not shrink more than 10% in either direction. The fabric also does not melt, drop, separate, or ignite under the application of heat. Under Manikin testing, the fabric ensures that the average predicted body burn does not exceed 50%.
Under ASTM F1506-17b, the fabric has a bursting strength of 275 kPa or 40 psi. The fabric also has a colorfastness under laundering shade Class 3.
The fabric disclosed herein can be used to form garments. The fabric disclosed herein can be incorporated into various clothing garments or used to form the entirety of a clothing garment.
Having thus described the present disclosure in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein.
It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein.
The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the embodiments being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.

Claims

What is claimed is:

1. A fabric formed of blended yarns comprising:

40%-60% inherently flame resistant fibers,

20%-60% non-flame resistant cellulose fibers, and

5%-30% flame resistant aramid structural fibers.

2. The fabric according to claim 1, wherein:

the inherently flame resistant fibers include modacrylic;

the non-flame resistant cellulose fibers include cotton or lyocell; and

the flame resistant aramid fibers include para-aramids or meta-aramids.

3. The fabric according to claim 1, wherein a weight of the fabric is between 4.5 ounces per square yard and 10.0 ounces per square yard.

4. The fabric according to claim 1, wherein yarns forming the fabric have yarn counts between 20/1 and 40/1, or a plied yarn of equivalent weight.

5. The fabric according to claim 1, wherein the fabric has a double knit circular configuration.

6. The fabric according to claim 1, wherein the fabric meets all of the following test methods: ASTM D6413; ASTM F1959; ASTM D3786; AATCC 61 Method A; AATCC 135; ASTM F2700; ASTM 1930; and ASTM 2894.

7. The fabric according to claim 1, wherein the fabric meets the requirements under NFPA 2112-2018 standard.

8. The fabric according to claim 1, wherein the fabric is treated with at least one of:

anti-microbial solutions, softeners, or anti-static solutions during a finishing process.

9. The fabric according to claim 1, wherein the fabric includes a flat channeled front surface and a rear surface including air-trapping pockets.

10. The fabric according to claim 1, wherein the fabric is configured to promote phobic and philic interactions to wick moisture away from a user.

11. The fabric according to claim 1, wherein the fabric is formed with a knit configuration having a four feed repeat configuration in which every other needle is removed.

12. The fabric according to claim 1, wherein the fabric is formed using a single or plied yarn.

13. The fabric according to claim 1, wherein the fabric is knit in tubular form.

14. The fabric according to claim 1, wherein the fabric is further dyed to color, and the dyeing temperature is less than 220° F.

15. The fabric according to claim 1, wherein the fabric is formed by a knitting machine including a cylinder having at least a 20 inch diameter and at least 600 needle positions.

16. The fabric according to claim 1, wherein the fabric meets all of the following industry testing standards: ASTM 1506-19a and NFPA 2112-2018.

17. A fabric formed of blended yarns comprising:

40%-60% inherently flame resistant fibers, the inherently flame resistant fibers including modacrylic;

20%-60% non-flame resistant cellulose fibers, the non-flame resistant cellulose fibers including cotton or lyocell; and

5%-30% flame resistant aramid structural fibers, the flame resistant aramid fibers including para-aramids or meta-aramids,

wherein the fabric has a double knit circular configuration,

the fabric includes a flat channeled front surface and a rear surface including air-trapping pockets,

the fabric is formed as a single or plied count yarn, and

a weight of the fabric is between 4.5 ounces per square yard and 10.0 ounces per square yard.

18. The fabric according to claim 17, wherein the fabric is formed with a knit configuration having a four feed repeat configuration in which every other needle is removed.

19. The fabric according to claim 17, wherein the fabric is knit in tubular form.

20. The fabric according to claim 17, wherein the fabric is formed by a knitting machine including a cylinder having at least a 20 inch diameter and at least 600 needle positions.