KR102272456B1 - Electric arcflash protection flame retardant laminated fabrics - Google Patents

Abstract

The present invention is a meta-aramid knit layer (1); a first meta-aramid fabric layer (2);
meta aramid nonwoven fabric felt layer (3); a second meta-aramid fabric layer (4); conductive fabric layer (5); And a coating layer (6) comprising an electrically conductive polymer, a water repellent and a flame retardant; relates to an electrical safety flame retardant protective clothing laminated fabric, characterized in that the sequentially laminated.
According to the present invention, while satisfying a grade equivalent to grade 4 of the ATPV HRC grade, it is excellent in flame retardancy, tensile, tear strength and flexibility, and as an electrical safety flame-retardant protective suit for workers performing work in an environment where there is a possibility of an electric arc It has the effect of providing a suitable laminated fabric.

Description

Electrical safety flame retardant protective clothing laminated fabric {ELECTRIC ARCFLASH PROTECTION FLAME RETARDANT LAMINATED FABRICS}

The present invention relates to an electrical safety flame-retardant protective clothing laminated fabric, and more particularly, it satisfies a grade equivalent to grade 4 according to ATPV HRC, and has excellent flame retardancy, tensile, tear strength and flexibility, and an environment in which an electric arc is possible It relates to a laminated fabric suitable for the protective clothing of workers performing work in

An arc flash is a type of electrical explosion or discharge due to light and heat generated as part of an arc fault, a low-impedance connection through the air or ground of an electrical system, or a different voltage phase. Such arc flash quickly vaporizes the metal conductor, expands the plasma to the outside, and can cause a serious explosion, which can cause fire and injury to not only electricians but also nearby workers.

The primary measure to protect workers who frequently come and go to areas prone to disasters due to such arc flash is to require workers to wear protective clothing, which is usually a mixture of meta-aramid and para-aramid and conductive fibers. Although a woven fabric is used, this fabric has some degree of electrical conductivity, but does not have satisfactory performance, and is woven thickly so that the operator may feel uncomfortable.

In one example, the Workrite Uniform Company (Oxford, CA) markets a garment (Style #410-NMX-85-DN) described as "denim jean cut pant". This garment contains Nomex® Type N-302 staple fibers (including crystallized meta-aramid fibers) in the warp direction of the fabric and Nomex® Type T-462 staple fibers (amorphous meta-aramid fibers) in the weft direction. -Appears to be made of fabric with aramid fibers). Although these fabrics have good arc protection performance, they do not have a satisfactory appearance and are generally very uncomfortable because they are composed almost entirely of aramid fibers.

Thus, while being durable, comfortable to wear, and suitable for the end user, NFPA 70E (“Standard for Electrical Safety in the Workplace”) and NFPA 2112 (“Protection of Industrial Personnel Against Flash Fires”) There is a need for flame-retardant fabrics that comply with industry standards as described in "Standard on Flame-Resistant Garments for Protection of Industrial Personnel Against Flash Fire."

Korean Patent Publication No. 2011-0033851 Korean Patent Publication No. 2013-0122396

In order to solve the problems of the prior art as described above, the present invention guarantees the safety of workers wearing protective clothing, and has excellent flame retardancy, tensile, tear strength and flexibility to perform work in an environment where there is a possibility of an electric arc. An object of the present invention is to provide a laminated fabric suitable for workers' protective clothing.

The above and other objects of the present invention can all be achieved by the present invention described below.

In order to achieve the above object, the present invention is a meta-aramid knit layer (1); a first meta-aramid fabric layer (2); meta-aramid non-woven fabric felt layer (3); a second meta-aramid fabric layer (4); conductive fabric layer (5); and a coating layer (6) comprising an electrically conductive polymer, a water repellent, and a flame retardant; provides an electrical safety flame retardant protective clothing laminated fabric, characterized in that it is sequentially laminated.

In addition, the laminated fabric of the present invention is characterized in that the flame-retardant thermoplastic film is arranged between the knit layer, the fabric layer and the nonwoven felt layer, and bonded by a pressure heating method.

The conductive fabric layer 5 may be mixed with 1 to 10% by weight of acrylic conductive fibers and 90 to 99% by weight of meta-aramid fibers.

The meta-aramid nonwoven felt layer 3 has a fineness of 1.5 to 3.0 denier, and a basis weight of 270 to 340 g/m ^{2 It} is characterized in that it is made of short meta-aramid fibers.

In addition, the present invention comprises the steps of preparing a meta-aramid knit layer; Preparing a meta-aramid fabric layer; preparing a conductive fabric layer; forming a coating layer comprising an electrically conductive polymer, a water repellent and a flame retardant on the conductive fabric layer; Preparing a nonwoven felt layer made of meta-aramid; and arranging the flame retardant thermoplastic film between the knit layer, the fabric layer and the nonwoven felt layer, and bonding each layer by a pressurized heating method. Provides a method for manufacturing a laminated fabric for electrical safety flame retardant protective clothing, comprising: .

According to the present invention, it guarantees the safety of workers wearing protective clothing, and has excellent flame retardancy, tensile, tear strength and flexibility. has the effect of providing.

1 is a cross-sectional view showing an electrical safety flame-retardant protective clothing laminated fabric according to an embodiment of the present invention.
Figure 2 shows the arc evaluation value of the electrical safety flame-retardant protective clothing laminated fabric according to an embodiment of the present invention.

Hereinafter, the electrical safety flame-retardant protective clothing laminated fabric of the present disclosure will be described in detail.

As a result of repeated research to develop a laminated fabric for electrical safety flame-retardant protective clothing, the present inventors include a felt layer made of meta-aramid fibers together with a fabric layer made of meta-aramid fibers as conductive acrylic fibers, and one or both sides of the fabric It was confirmed that when each layer is combined by placing a flame-retardant thermoplastic film, it was confirmed that the flame flowing into the fabric could be blocked, and based on this, we focused on research. As a result, the knit layer and the fabric layer made of meta-aramid fibers, and the non-woven felt layer It was confirmed that a fabric that satisfies the grade equivalent to grade 4 according to ATPV HRC can be manufactured when a coating layer containing an electrically conductive polymer is formed by sequentially stacking the layers, and based on this, the present invention was completed.

Electrical safety flame retardant protective clothing laminated fabric of the present invention is a meta-aramid knit layer (1); a first meta-aramid fabric layer (2); meta aramid nonwoven fabric felt layer (3); a second meta-aramid fabric layer (4); conductive fabric layer (5); and a coating layer 6 comprising an electrically conductive polymer, a water repellent, and a flame retardant; characterized in that it is sequentially stacked.

The meta-aramid fiber according to the present invention may use a fiber of a flame retardant material having a limiting oxygen index (LOI) of 26 or more. These meta-aramid fibers have the effect of preventing the spread of damage to the yarn due to exposure to flame.

The present invention has a feature that can provide a laminated fabric with increased tensile strength and tear strength by including the meta-aramid knit layer (1).

The meta-aramid yarn forming the knit layer 1 is a spun yarn having a thickness of 20 to 50, and it is preferable to use a double-plied ply-twisted yarn ply-twisted to have an s twist with a covering density (T/M) of 400 to 450. preferred in terms of

The thickness of the yarn can be represented by the number ('S) of the number, and the greater the number, the thinner the thickness of the yarn. In one embodiment, the thickness of the meta-aramid yarn for knitting forming the knit layer is preferably in the range of 20 to 50, or 20 to 30, in terms of flame retardancy and weaving properties.

In addition, if the T/M is less than 400, the workability becomes poor and the expression of tensile strength becomes difficult. As the yarn protrudes to the surface of the fabric, the appearance of the fabric is poor.

In addition, excessive T/M can also be a factor in the failure of warp and weft yarns in weaving.

The first meta aramid fabric layer (2) and the second meta aramid fabric layer (4) of the present invention is a fineness of 2 to 5 denier, preferably 2 to 3 denier of meta aramid fibers in the range of plain weave, or twill weave to meta An aramid fabric layer can be formed.

In addition, the meta aramid fiber is preferably 70mm or more in length, or using a fiber in the range of 70 to 100mm can increase tensile and tear strength.

As a specific example, the meta-aramid yarn used for manufacturing the first meta-aramid fabric layer (2) and the second meta-aramid fabric layer (4) may be a 20s/2 780T/M ply-twisted yarn in a wasted spinning process, In this case, there is an effect that can increase the tensile and tear strength compared to the fabric through the cotton spinning process using fibers of a length of usually 38 to 52 mm.

Since the first meta-aramid fabric layer is directly related to the flame retardancy, it is preferable to use a thick fabric as much as possible, and in the present invention, a coarse count of 20's/2 was used.

In addition, the second meta-aramid fabric layer uses the same number as the first meta-aramid fabric layer, or it is preferable to optimize the warp and weft density to reduce the porosity between fibers of the fabric.

In addition, the meta-aramid fibers forming the first meta-aramid fabric layer (2) and the second meta-aramid fabric layer (4) may be formed using the same yarn as the meta-aramid yarn forming the knit layer (1). .

Meta-aramid non-woven felt layer (3)

The meta-aramid nonwoven felt layer 3 of the present invention has a fineness of 1.5 to 3.0 denier, and a basis weight of 270 to 340 g/m ² is characterized in that it is made of short meta-aramid fibers.

The meta-aramid non-woven felt layer 3 has an average length of 45 to 55 mm and an average thickness of 15 to 25 μm of meta-aramid short fibers opened by a conventional carding method to form a web, and this cross-lapper (cross lapper) It can be formed by laminating to have a constant thickness and width at a basis weight of 100 to 120 gr/m ^{2 using a eg.}

Here, the carding method is a method of opening each fiber, mixing as needed, and forming this mixture into a web using a carding machine.

In addition, the laminated web may have a more stable shape by needle punching. In this case, the web is needle punched once at a density of about 380 to 400 pps in a needle puncher, and then, a nozzle diameter of 0.15 mm and a nozzle density of 24 nozzles It can be manufactured by water punching the web while supplying water at a water pressure of 200 bar using a nozzle formed in /cm. In this case, in the water punch process, water may be supplied to only one side of the web.

The meta-aramid fibers included in the meta-aramid nonwoven felt layer 3 may have a fineness of 1.5 to 3.0 denier, and in particular, it is preferable to use short fibers of 2.5 denier or less to increase air permeability, average pore size, and thermal barrier properties. Do.

For example, the meta-aramid nonwoven felt layer 3 may have an air permeability of 30-100 cm ³ /cm ² /sec, and an average pore size of 15-25 μm.

The air permeability of the present substrate can be measured, for example, by using a Frazier air permeability meter, according to the provisions of the ASDM D737 method, the air permeability of the fabric.

Conductive fabric layer (5)

The conductive fabric layer 5 of the present invention is characterized in that it is formed including conductive acrylic fibers and meta-aramid fibers.

While these conductive acrylic fibers have a high degree of flame retardancy that can stop the spread of damage to the fabric due to exposure to flame, they do not have adequate tensile strength to provide the desired level of rupture resistance when exposed to an electric arc. , the present invention includes meta-aramid fibers to improve tensile strength.

As an example, the meta-aramid fabric layer 5 may be formed by combining the conductive acrylic fibers with the warp and weft yarns in the fabric woven using the meta-aramid fibers.

The conductive fabric layer 5 preferably contains 1 to 10% by weight of acrylic conductive fibers and 90 to 99% by weight of meta-aramid fibers because both flame retardancy and tensile strength can be excellent.

The conductive acrylic fiber may be, for example, an acrylic synthetic fiber prepared from a polymer mainly containing acrylonitrile.

Specifically, the conductive acrylic fiber of the present invention reacts copper sulfate (CuCO4) with an acrylic fiber containing conductive acrylonitrile as a main raw material to chemically combine compounds such as copper (Cu), cyanide (CN), and sulfur (S). , ^{It is preferable to use an antistatic fiber having conductivity of 10 -1} to 10 ^-2 Ω/cm because it is stable against mechanical friction and chemical action as well as excellent blending properties with other fiber materials.

The conductive acrylic fiber of the present invention has an excellent antistatic effect even if it is mixed with other fiber materials by only 1 to 5%, and has excellent heat storage function and electromagnetic wave shielding function, so it can be expected to be applied to the semiconductor industry or military supplies.

As a specific example, using Elex acrylic conductive yarn of H company as the conductive acrylic fiber, it is passed through meta-aramid yarn and ply-twisted yarn, and impregnated in 8% phosphorus-based flame retardant solution using a single yarn sizing machine, dried at 210 ° C. A flame-retardant conductive acrylic fiber was prepared and used.

Coating layer (6) comprising an electrically conductive polymer, a water repellent and a flame retardant

The coating layer 6 according to the present invention includes an electrically conductive polymer, a water repellent and a flame retardant, and is formed on the conductive fabric layer 5 .

The electrically conductive polymer of the present invention is polyparaphenylenes, polyparaphenylenevinylenes, polyanilines, polyazines, polythiophenes, poly-p-phenylene sulfide (poly-p-phenylene sulfides), polyfuranes, polypyrroles, polyselenophenes, polyacetylenes, and combinations thereof, in particular The use of an electrically conductive polymer containing polyaniline is preferable because it prevents deterioration of the conductive performance due to breakage or breakage of the conductive acrylic yarns arranged on the fabric, and at the same time can impart uniform conductivity to the fabric surface.

The water repellent of the present invention may use a water repellent generally used in the field to which the present invention belongs, for example, a pyridine-based, silicone resin-based, fluororesin compound, etc. may be used, and using a water repellent containing a fluororesin compound is water repellent It is preferable in terms of improvement.

The flame retardant of the present invention may use a phosphorus-based flame retardant, a nitrogen-based flame retardant, or a mixture thereof.

The phosphorus-based flame retardant may be, for example, at least one selected from the group consisting of triphenyl phosphate, cresyl diphenyl phosphate, isopropylphenyl diphenyl phosphate, and mixtures thereof.

The nitrogen-based flame retardant may be at least one selected from the group consisting of melamine, melamine phosphate and melamine cyanurate.

Although flame retardancy may be lowered by the use of a water repellent, in order to maintain both water repellency and flame retardancy in an excellent state by mixing a water repellent and a flame retardant, in the present invention, a water repellent and a liquid phosphorus-based flame retardant are mixed and the pad-dry-cure at a 75% pick-up rate It is characterized in that the coating layer 6 is formed by hot air drying treatment at 190 to 200° C. by a pad-dry-cure (PDC) method.

In addition, the laminated fabric of the present invention can block the flow of high voltage current caused by moisture or water penetration by placing the flame retardant thermoplastic film between the knit layer, the fabric layer and the nonwoven felt layer and bonding it by a pressurized heating method. has the effect of increasing the safety of

The flame-retardant thermoplastic film may be, for example, a flame-retardant thermoplastic urethane film, and specifically may be prepared by melt-mixing a thermoplastic urethane resin and a phosphonate oligomer, a phosphonate polymer, and a phosphonate-containing copolymer.

Such a thermoplastic urethane film may have a hardness of, for example, 80 to 90A, and in this case, there is an effect of increasing the bonding force between each layer. Here, the hardness may be measured using ASTM D2240 as an example, and shore hardness at 25°C.

In addition, the present invention comprises the steps of preparing a meta-aramid knit layer; Preparing a meta-aramid fabric layer; preparing a conductive fabric layer; forming a coating layer comprising an electrically conductive polymer, a water repellent and a flame retardant on the conductive fabric layer; Preparing a nonwoven felt layer made of meta-aramid; and arranging the flame retardant thermoplastic film between the knit layer, the fabric layer and the nonwoven felt layer, and bonding each layer by a pressurized heating method. Provides a method for manufacturing a laminated fabric for electrical safety flame retardant protective clothing, comprising: .

Preparing the meta-aramid knit layer; can be prepared as a knitted fabric using 20's'/2 430 T/M ply-twisted yarn.

The step of preparing the meta-aramid fabric layer; is, for example, using a 20's/2 780 T/M ply-twisted yarn in a wasted spinning process, in a weight of 320 to 360 gr/m ² It can be prepared as a plain weave with a rapier loom. have.

The step of preparing the conductive fabric layer; is, for example, a meta-aramid fiber, a flame-retardant material having an LOI value (limiting oxygen index) of 26 or more; and a basis weight of 4.5gr/d or more, and a length of 76mm having a heat resistance of 285°C or more It can be manufactured through a process of kneading conductive acrylic fibers of ~102 mm with each other.

The spun yarn produced by this process has excellent and uniform binding force between the two fibers, and by using the woven yarn, a fabric with increased tensile strength and tear strength can be manufactured.

In addition, it can be weaved on an air jet loom or a rapier loom, and what is made by twisting the S yarn and Z yarn with T/M 430 to 840 can be used.

Preparing a nonwoven felt layer made of meta-aramid; can form a web by opening 100% by weight of meta-aramid short fibers having an average length of 51 mm and an average thickness of 20 μm by a conventional carding method. At this time, it is possible to form a web of ^{100 to 120 gr/m 2} level by laminating using a general cross wrapper.

Then, the web is needle punched once at a density of about 380 to 400 pps in a needle puncher, and then, using a nozzle formed with a nozzle diameter of 0.15 mm and a nozzle density of 24 / cm, while supplying water at a water pressure of 200 bar, the web A nonwoven felt layer made of meta-aramid of the present invention can be prepared by water punching.

Forming a coating layer comprising an electrically conductive polymer, a water repellent, and a flame retardant on the conductive fabric layer; is a conductive polymer polyaniline aqueous solution, a phosphorus-based liquid flame retardant, and a fluorine-based water repellent to the surface of the fabric by treating the surface of the fabric with a conductive and repelling water repellent To form a layer, it is possible to maximize moisture penetration or contact repulsion of hazardous chemicals.

The surface water repellency of the fabric is to minimize the contact angle when the surface of the fabric is in contact with a liquid so that the fabric does not get wet. It should be treated by coating with a hydrophobic material and weaving densely to prevent the passage of water.

In general, since synthetic fibers are inherently hydrophobic, a slight water repellency function is imparted even when an ultra-high-density fabric is manufactured without additional treatment. Materials mainly used as water-repellent materials are pyridine-based (DuPont Zelan, ICI Velan), silicone resin-based (MHPS, Methylhydrogen polysiloxane), and fluororesin compounds (3M, Scotchgard).

However, if only an excessive water-repellent effect is required, the flame retardancy by the water-repellent agent is lowered, so a surface treatment technology that maintains the water-repellent property and flame retardancy by mixing the existing water-repellent agent and the phosphorus-based liquid flame retardant is required. Therefore, in the present invention, after dispersing and mixing a conductive polymer, a fluorine-based water repellent agent and a phosphorus-based flame retardant, the effect of water repellency and flame retardancy was maintained by hot air drying at 190 ~ 200 ° C using the Pad-Dry-Cure method at a 75% pick-up rate.

Electrical safety flame retardant protective clothing laminated fabric according to the present invention provides excellent flame and heat protection performance for flame retardant applications according to industry standard test methods.

The laminated fabric of the present invention is characterized in that it meets the performance requirements for electric arc rating for HRC level 4 according to at least NFPA standard 70 E (2012).

Alternatively, the laminated fabric of the present invention is characterized in that it has an arc thermal performance value ^{of 25Cal/cm 2 or more.}

The above NFPA 70 E is the standard handling electrical safety requirements and provides information on all aspects of electrical safety in the workplace. NFPA 70 E provides a method for fitting hazmat suits to potential exposure levels that combine hazard hazard categories (HRCs). Protective fabrics are tested to measure their ATPV (Arc flash Thermal Performance Value), or arc evaluation value, in cal/cm ^{2 .}

ATPV is measured by ASTM Test Method F1959, which uses a sensor to measure the thermal energy properties of a specimen of protective fabric while exposed to a series of electric arcs. The measured arc rating determines the HRC Level of the fabric, where Hazard Levels 1, 2, 3 and 4 correspond to heat flux through the fabric of ^{4, 8, 25 and 40 Cal/cm 2 , respectively.}

The laminated fabric according to the present invention may constitute the whole or various parts of various protective clothing for protecting the wearer from electric arc flash and flame, and furthermore, the chemical processing industry or industrial electrical/equipment where extreme heat-related events may occur. Pants, shirts, gloves, sleeves, etc. that can be worn in such situations may be included.

In addition, the laminated fabric according to the present invention may be applied to coveralls, jumpsuits, shirts, jackets, vests and trousers.

Hereinafter, preferred examples are presented to aid the understanding of the present invention, but the following examples are merely illustrative of the present invention and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention, It goes without saying that such variations and modifications fall within the scope of the appended claims.

[Example]

Example

-Meta-aramid knit layer

The meta-aramid yarn forming the knit layer 1 is knitted using a double-twisted meta-aramid ply-twisted yarn that is a spun yarn having a thickness of 20 to 50 and a covering density (T/M) of 400 to 450 to have an s twist. layers were prepared.

-The first meta-aramid fabric layer and the second meta-aramid fabric layer

Meta-aramid yarns were plain ^{weaved with a rapier loom at 320 gr/m 2} using 20s/2 780T/M ply-twisted yarns as a wasted spinning process.

- Conductive fabric layer

After the process of kneading 95% of meta-aramid fiber and 5% of conductive acrylic fiber, which is a flame retardant material having an LOI value (limiting oxygen index) of 26 or more, it was manufactured with a rapier loom at a ^{weight of 320 to 360 gr/m 2 .}

After that, the surface of the woven fabric was dispersed and mixed with an aqueous solution of polyaniline, a conductive polymer, a phosphorus-based liquid flame retardant (Poongrim Emulsification HEXA NON CPRF), and a fluorine-based water repellent (Nicca Korea's KF GUARD 2000) and then pad-dry at a 75% pick-up rate. The coating layer was formed by hot air drying at 190 ~ 200 °C by the -cure method.

- Non-woven felt layer made of meta-aramid

100% by weight of meta-aramid short fibers having an average length of 51 mm and an average thickness of 20 μm are opened by a conventional carding method to form a web, and then laminated using a cross wrapper to achieve a level of ^{100-120 gr/m 2} A web was formed. The web is needle-punched once at a density of about 380 to 400 pps in a needle puncher, and then the web is watered while supplying water at a water pressure of 200 bar using a nozzle formed with a nozzle diameter of 0.15 mm and a nozzle density of 24/cm. A nonwoven felt layer made of meta-aramid was prepared by punching.

Each prepared layer was sequentially laminated with a meta-aramid knit layer, a first meta-aramid fabric layer, a meta-aramid nonwoven felt layer, a second meta-aramid fabric layer, and a conductive fabric layer, as shown in Fig. 1 below, between each layer. Each layer was adhered using a TPU film having a hardness of 85A.

[Experiment result]

^{ATPV, that is, the arc evaluation value (cal/cm 2} ) was measured using the thermal energy characteristic of the protective fabric test piece as a sensor while the laminated fabric prepared in the above example was exposed to a series of electric arcs according to ASTM test method F1959. ,

It could be confirmed that the arc evaluation value was 25 (cal/cm ^{2 ) as shown in Fig. 2 below.}

1: meta aramid knit layer 2: first meta aramid fabric layer
3: meta aramid nonwoven felt layer 4: second meta aramid fabric layer
5: Conductive fabric layer
6: Coating layer 7: Flame-retardant thermoplastic film

Claims (5)

A meta-aramid knit layer (1) formed of a double-twisted meta-aramid ply-twisted yarn having a thickness of 20 to 50 spun yarn with a covering density of 400 to 450 T/M and ply-twisted;
a first meta-aramid fabric layer (2);
A meta-aramid nonwoven felt layer (3) having a fineness of 1.5 to 3.0 denier, and a basis weight of 270 to 340 g/m ^{2 of meta-aramid short fibers;}
a second meta-aramid fabric layer (4);
Conductive fabric layer (5) mixed with 1-10 wt% of acrylic conductive fiber and 90-99 wt% of meta-aramid fiber; and
A coating layer (6) comprising an electrically conductive polymer, a water repellent and a flame retardant; is sequentially laminated,
The first meta-aramid fabric layer (2) and the second meta-aramid fabric layer (4),
It is formed of a meta-aramid ply-twisted yarn with a covering density of 780T/M as a spun yarn having a length in the range of 70 to 100mm and a thickness of 20s/2,
Between the meta aramid knit layer (1), the first meta aramid fabric layer (2), the meta aramid nonwoven felt layer (3), the second meta aramid fabric layer (4), the conductive fabric layer (5) and the coating layer (6) Electrical safety flame-retardant protective clothing laminated fabric, characterized in that each of the flame-retardant thermoplastic films are arranged and combined by a pressurized heating method.
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