DESC:TECHNICAL FIELD OF THE INVENTION
The present invention relates to wearable flame retardant thermal protective fabrics.
BACKGROUND OF THE INVENTION
A flame retardant personal protective-wear is typically used to safeguard a person from a risk of electric arc and/or flash fires. However, when garments are manufactured by using flame-resistant fibers, the yarns or fabric may break open easily upon exposure to the intense thermal stress of an electrical arc due to lower tensile strength of the flame-resistant fibers. This break open of the yarn or fabric may render the wearer to additional injury. Moreover, if the weather condition is cold, then there is a need of additional protective apparel which protects the wearer from extreme cold weather conditions. However, requirement of two garments for protection against fire hazard and against cold increases the cost of usage. Further, it may become uncomfortable for a wearer to wear two garments.
Therefore, there is felt a need for a fabric which can confer better protection to a wearer from fire hazard as well as from cold even in extreme weather conditions.
SUMMARY OF THE INVENTION
The present invention discloses an inherently flame retardant fabric. The fabric is a corduroy fabric and comprises blend of either cellulosic and Modacrylic fibers, or Aramid/ and flame retardant cellulosic fibers, or aramid having antistatic fibre.
In an embodiment, the fabric comprises an intimate blend of 30% to 55% w/w modacrylic fibers, 30% to 55% w/w cotton fibers, 0% to 10% w/w polyamide fibers, 0% to 10% w/w para aramid fibers, and 0% to 2% w/w anti-static fibers.
In another embodiment, the fabric comprises an intimate blend of 30% to 70% w/w meta aramid fibers, 3% to 10% w/w para aramid fibers, 30% to 70% w/w flame retardant viscose fibers, and 0% to 2% w/w anti-static fibers.
In yet another embodiment, the fabric comprises an intimate blend of 75% to 93% w/w meta aramid fibers, 5% to 25% w/w para aramid fibers, 0% to 2% w/w anti-static fibers.
The present invention further discloses a flame retardant fabric. The fabric is corduroy fabric. The fabric comprises at least 50% w/w non-flame retardant cellulosic fibres.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
The detailed description is described with reference to the accompanying figures. In the figures, the reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and modules.
A flame retardant wearable fabric is now described with reference to accompanying drawing, in which:
Figure 1 shows a process route for treated flame retardant fabric; and
Figure 2 shows a process route for inherently flame retardant fabric.
DETAILED DESCRIPTION OF THE INVENTION
Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.
References in the specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
The present invention discloses a flame retardant wearable fabric that provides protection against fire hazard as well as provides protection against cold to the wearer. The fabric is comfortable to wear.
The fabric is corduroy fabric. The fabric comprises at least 50% w/w non-flame retardant cellulosic fibres.
In an embodiment, the fabric has an intimate blend of at least 50% w/w non-flame retardant cellulosic fibres, and 0% to 50% w/w synthetic fibers.
In another embodiment, the fabric has an intimate blend of 50% w/w cotton and 50% w/w Nylon 66. In another embodiment, the fabric has an intimate blend of 88% w/w cotton and 12% w/w Nylon 66. In yet another embodiment, the fabric has an intimate blend of 80% w/w cotton and 0% w/w polyester.
In an embodiment, the cellulosic fibers are selected from the group consisting of cotton, Lyocell, Viscose, Modal, and Cuprammonium.
In another embodiment, the synthetic fibers are selected from the group consisting of polyester, Polyamide, and acrylic.
The fabric has corduroy weaves. The corduroy woven fabric provides protection against cold. To provide protection against flame/fire hazard, the fabric is treated with THPX chemistry.
The flame retardant corduroy fabric has wale ranging from 6 to 24 per inch of the fabric.
In an embodiment, the yarn of the flame retardant fabric is a single count yarn having yarn count ranging from12s Ne to 50s Ne.
In another embodiment, the yarn of the flame retardant fabric is a double count yarn having yarn count ranging from 2/24s Ne to 2/100s Ne.
The Moisture Vapour Transmission Rate (MVTR) of the fabric is more than 2000 gm/M2/Day.
The fabric has abrasion resistance of more than 50000 revolutions.
Referring to Fig. 1, a process route for manufacturing the treated flame retardant corduroy fabric is shown in accordance with an embodiment of the present invention.
Initially, a blend of at least 50% w/w non-flame retardant cellulosic fibres, and remaining synthetic fibers is prepared. The blend is then processed through a ring spinning machine to obtain a yarn. A plurality of yarns is then processed through a weaving machine to obtain a fabric. The fabric has corduroy weaves. The weaving (100) of the fabric is made in loops, thereafter the fabric is transferred to a wale cutting machine (102) where the loops are cut. Further, the loops of fabric are transferred for mending (104) to cut threads. The process is then repeated, if any thread remains uncut. This also ensures that the face side of the fabric will remain same in every process. Furthermore, the loops of fabric are transferred for brushing (106) which makes the cut yarn twist less and provides a rich velvet appearance and thickness which are an important factor for thermal insulation as well as electric arc protection. After brushing (106), the fabric is transferred for desizing (110). Further, the fabric undergoes a rewind process (112) in between the scouring and mercerisation (114). Further, the rewind processes (116, 120, 124, 128, 132, 136, 142) are usually done before every treatment. After mercerisation (118) and rewinding (116), the fabric proceeds for wet brushing (112) which is a very important process to make the proper orientation of wale fibre and to avoid dyeing defects like patches or tailing or centre to selvedge variation etc. Further, the fabric goes for dyeing (126) if the fabric includes 100% cellulosic, cellulosic /polyamide, cellulosic/ polyester and cotton/acrylic. The cellulosic /polyamide blends with vat dye through PDPS method/process. The cellulosic/ polyester fibers blend with vat a disperse dye with both the PDPS and thermosoling processes. The cotton/acrylic fibers blend with vat and cationic dye class which is used with exhaust method. For all these blends except 100% cellulosic fibers blend, the fabric goes for Heat set process at about 1800C for at least 30 seconds on stenter followed by rewinding (128) for thermo-dimensional stability. Further, the fabric is treated with THPX chemistry (130) followed by ammonia curing and oxidative washing. This is done to make the fabric flame retardant. The fabric then undergoes finishing process. In the finishing process, the fabric is treated with a softener or any other chemical like anti-microbial, oil and water repellent, stain release. The fabric then undergoes rewinding (136) and sanforising (138) and then gain rewinding (140) and final brushing (142) processes. The sanforisation (138) process makes the fabric dimensionally stable and then the final brushing (142) makes the wall fibre on proper orientation which will provide thermal insulation as well as rich corduroy appearance.
The present invention further discloses a garment made of the treated flame retardant corduroy fabric. The garment comprises at least 50% w/w non-flame retardant cellulosic fibres, and remaining synthetic fibers.
The present invention further discloses an inherently flame retardant fabric. The fabric is a corduroy fabric and comprises blend of either cellulosic and Modacrylic fibers, or Aramid/ and flame retardant cellulosic fibers, or aramid having antistatic fibre.
In an embodiment, the fabric comprises an intimate blend of 30% to 55% w/w modacrylic fibers, 30% to 55% w/w cotton fibers, 0% to 10% w/w polyamide fibers, 0% to 10% w/w para aramid fibers, and 0% to 2% anti-static fibers.
In another embodiment, the fabric comprises an intimate blend of 30% to 70% w/w meta aramid fibers, 3% to 10% w/w para aramid fibers, 30% to 70% w/w flame retardant viscose fibers, and 0% to 2% w/w anti-static fibers.
In yet another embodiment, the fabric comprises an intimate blend of 75% to 93% w/w meta aramid fibers, 5% to 25% w/w para aramid fibers, 0% to 2% w/w anti-static fibers.
In an embodiment, the yarn of the inherently flame retardant fabric is a single count yarn having yarn count ranging from12s Ne to 50s Ne.
In another embodiment, the yarn of the inherently flame retardant fabric is a double count yarn having yarn count ranging from 2/24s Ne to 2/100s Ne.
The inherently flame retardant corduroy fabric has wale ranging from 6 to 24 per inch of the fabric.
The Moisture Vapour Transmission Rate (MVTR) of the fabric is more than 2000 gm/m2/Day.
The fabric has abrasion resistance of more than 50000 revolutions.
Referring to Fig. 2, a process route for manufacturing the inherently flame retardant fabric is shown in accordance with an embodiment of the present invention.
Initially, a blend of either cellulosic and Modacrylic fibers, or Aramid/ and flame retardant cellulosic fibers, or aramid having antistatic fibre is prepared. The blend is then processed through a ring spinning machine to obtain a yarn. A plurality of yarns is then processed through a weaving machine to obtain a fabric. The fabric has corduroy weaves. The weaving (200) of the fabric is made in loops. Thereafter, the fabric is transferred to the wale cutting machine (202) where the loops are cut. Further, the loops of fabric are transferred for mending (204) to cut the threads. The process is then repeated, if any thread is remain uncut. This also ensures that the face side of the fabric will remain same in every process. The fabric then undergoes brushing (206) which makes the cut yarn twist less and provides a rich velvet appearance and thickness which are an important factor for thermal insulation as well as electric arc protection. After brushing (206), the fabric proceeds for rewind process (208). The fabric is then loaded in soft-flow /JET machine for dyeing pre-treatment (210) to remove any add or natural impurities and dyeing. Here, the dyeing method is exhaust method and the dyes which are used are cationic dyes for modacrylic, aramid and reactive dyes for flame-retardant cellulosic part. In this process, the fabric is loaded in soft-flow/JET machine, hence there is no need for wet brushing/ rewinding process as the fabric is in rope form and further, washing every time which makes the wale fibre in proper orientation. However, the process can be carried out on High Temperature High Pressure (HTHP) Jigger Machine, but in this process after the dyeing pre-treatment (210), the fabric undergoes rewind (212) process and further undergoes wet brushing followed by a rewind process. Further, the fabric is washed on a soft-flow/jet machine and then dyed on the Jigger machine. The fabric undergoes finishing process (214). In the finishing process, the fabric is treated with a softener or any other chemical like anti-microbial, oil and water repellent, stain release. The fabric is then transferred for rewinding (216) followed by sanforising (218) followed by rewinding (220) and final brushing (222). The sanforisation process (218) makes the fabric dimensionally stable and final brushing (222) makes the wale fibre on proper orientation which provides thermal insulation and rich corduroy appearance.
The present invention further discloses a garment made of the inherently flame retardant corduroy fabric. The garment comprises blend of either cellulosic and Modacrylic fibers, or Aramid/ and flame retardant cellulosic fibers, or aramid having antistatic fibre.
Below are few examples of the flame retardant fabrics of the present invention.
Example 1:
The fabric comprises 50% w/w cotton fibers, 48% modacrylic fibers, and 2% w/w anti-static fibers.
The properties of the fabric having aforementioned fibers are provided below.
Yarn: 2/40s Ne,
Construction: EPI:66, PPI: 122, Gsm: 240 , Weave: corduroy 10 wales/Inch
Tensile Strength (ISO 13934-1): warp: 500N, Weft: 350N
Tear Strength (ISO 13937-2): warp:25 N, Weft: 26N
Abrasion (ISO 12947-2): more than 30000 (no thread break)
Pilling (ASTMD3512): 4 ( out of scale 5)
Vertical Flame Test(ASTM D 6413 WEFT): Damage Length 75mm (Requirement less than 100mm for NFPA2112 AND Less than 152 mm ASTM 1590)
MVTR(ASTM E-96-05): 2300 gm/m2/Day
Example 2:
The fabric comprises 88% w/w cotton fibers, and 12% polyamide 66 fibers.
The properties of the fabric having aforementioned fibers are provided below.
Yarn: 30s Ne,
Construction: EPI:82, PPI: 138, Gsm: 215, Weave: corduroy 10 wales/Inch; Chemical Finish after Dyeing: THPX Chemistry
Tensile Strength (ISO 13934-1): warp: 450N, Weft: 350N
Tear Strength (ISO 13937-2): warp:20 N, Weft: 24N
Abrasion (ISO 12947-2): more than 100000 (no thread break)
Pilling (ASTMD3512): 4 (out of scale 5)
Vertical Flame Test (ASTM D 6413 WEFT): Damage Length 85mm (Requirement less than 100mm for NFPA2112 AND Less than 152 mm ASTM 1590)
MVTR(ASTM E-96-05): 2100 gm/m2/Day

Example 3
The fabric comprises 93% w/w meta aramid fibers, 5% w/w para aramid fibers and 2% anti-static fibers.
The properties of the fabric having aforementioned fibers are provided below.
Yarn: 2/40s Ne,
Construction: EPI:66, PPI: 122, Gsm: 240 , Weave: corduroy 10 wales/Inch
Tensile Strength (ISO 13934-1): warp: 1500N, Weft: 1000N
Tear Strength (ISO 13937-2): warp: 35 N, Weft: 35N
Abrasion (ISO 12947-2): more than 100000 (no thread break)
Pilling (ASTMD3512): 4 (out of scale 5)
Vertical Flame Test (ASTM D 6413 WEFT): Damage Length 88mm (Requirement less than 100mm for NFPA2112 AND Less than 152 mm ASTM 1590)
MVTR(ASTM E-96-05): 2200 gm/m2/Day
Example 4
The fabric comprises 58% w/w flame retardant viscose fibers, 30% w/w meta aramid fibers, 10% w/w para aramid fibers, and 2% anti-static fibers.
The properties of the fabric having aforementioned fibers are provided below.
Yarn: 2/40s Ne,
Construction: EPI:66, PPI: 222, Gsm: 245, Weave: corduroy 10 wales/Inch;
Tensile Strength (ISO 13934-1): warp: 800N, Weft: 600N
Tear Strength (ISO 13937-2): warp:25 N, Weft: 25N
Abrasion (ISO 12947-2): more than 100000 (no thread break)
Pilling (ASTMD3512): 4 (out of scale 5)
Vertical Flame Test (ASTM D 6413 WEFT): Damage Length 75 mm (Requirement less than 100mm for NFPA2112 AND Less than 152 mm ASTM 1590)
MVTR(ASTM E-96-05): 2200 gm/m2/Day
The corduroy fabric of the present invention has permanent flame retardant properties. The fabric has sufficient air gaps to provide the required thermal insulation for protection against cold. The fabric is suitable for electric arc protection as well as protection against molten metal as it comprises flame retardant fibers.
The fabrics described herein are breathable (air permeable, moisture vapour permeable) which helps reduce perspiration and provides greater comfort to the user for longer periods of time. The MVTR (Moisture Vapour Transmission Rate) as per ASTM E-96-05 of the fabric is more than 2000 gm/M2/Day. The fabric has high abrasion resistance of more than 50000 revolutions in an abrasion test. The fabric is dimensionally stable (i.e., display reduced stretching or shrinking), and optionally further comprise other functional durable finishes such as an anti-microbial finish, water and oil repellent coatings, stain release coatings and the like, without affecting protective performance.
The smooth appearance of flame retardant fabric is due to corduroy weaves which also provides an attractive look, good wicking properties, high breathability, high thermal insulation, high strength as well as comfort which makes a perfect flame retardant cold protective fabric.
The protective fabric described herein complies with standards such as NFPA 2112, ISO 11611, ASTM F1959/F1959M – 13, EN 61482-1-1. The NFPA 2112 standard is a standard defined by the National Fire Protection Association (NFPA) of united States which provides minimum requirements for the design, construction, evaluation, and certification of flame-resistant garments for use by industrial personnel, with the intent of not contributing to the burn injury of the wearer, providing a degree of protection to the wearer, and reducing the severity of burn injuries resulting from short-duration thermal exposures or accidental exposure to flash fires.
“Tensile strength” refers to the maximum amount of stress that can be applied to a material before rupture or failure. The “tear strength” is the amount of force required to tear a fabric. In general, the tensile strength of a fabric relates to how easily the fabric will tear or rip. The tensile strength may also relate to the ability of the fabric to avoid becoming permanently stretched or deformed. The tensile and tear strengths of a fabric should be high enough so as to prevent ripping, tearing, or permanent deformation of the garment in a manner that would significantly compromise the intended level of protection of the garment.
The International Organization for Standardization (ISO) is an international standard-setting body composed of representatives from various national standards organizations. ISO 11611 is standard for Protection against small splashes of molten metal and brief contact with flame. Protective clothing certified according to ISO 11612 gives the wearer protection against brief contact with heat and flame. The heat can be convective, radiant, molten material, or a combination thereof. Other standards are: ASTM F1959/F1959M – 13: Standard Test Method for Determining the Arc Rating of Materials for Clothing. EN 61482-1-1: Determination of the arc rating (ATPV) of flame resistant materials for clothing.
The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.
,CLAIMS:
1. An inherently flame retardant wearable fabric, said fabric is a corduroy fabric having an intimate blend of:
30% to 55% w/w modacrylic fibers;
30% to 55% w/w cotton fibers;
0% to 10% w/w polyamide fibers;
0% to 10% w/w para aramid fibers; and
0% to 2% w/w anti-static fibers.
2. An inherently flame retardant wearable fabric, said fabric is a corduroy fabric having an intimate blend of:
30% to 70% w/w meta aramid fibers;
3% to 10% w/w para aramid fibers;
30% to 70% w/w flame retardant viscose fibers; and
0% to 2% w/w anti-static fibers.
3. An inherently flame retardant wearable fabric, said fabric is a corduroy fabric having an intimate blend of:
75% to 93% w/w meta aramid fibers;
5% to 25% w/w para aramid fibers; and
0% to 2% w/w anti-static fibers.
4. A treated flame retardant wearable fabric, said fabric is a corduroy fabric having an intimate blend of:
at least 50% w/w non-flame retardant cellulosic fibers; and
0% to 50% w/w synthetic fibers;
said fabric is treated with THPX chemistry to make the fabric flame retardant.
5. The fabric as claimed in any of the claims 1-4, wherein yarn count of a yarn of said fabric ranges from 12s Ne to 50s Ne.
6. The fabric as claimed in any of the claims 1-4, wherein yarn count of a yarn of said fabric ranges from 2/24s Ne to 2/100s Ne.
7. The fabric as claimed in any of the claims 1-4, wherein said fabric has wale ranging from 6 to 24 per inch.
8. The fabric as claimed in any of the claims 1-4, wherein Moisture Vapour Transmission Rate (MVTR) of said fabric is more than 2000 gm/m2/Day.
9. The fabric as claimed in any of the claims 1-4, wherein said fabric has abrasion resistance of more than 50000 revolutions.