Aramid flame retardant fabric development

 Domestic flame-retardant textiles are mostly pure chemical fiber or cotton finishing products, ubiquitous hand feel hard, low strength, the case of fire and other defects melt drop, set durability, taking the overall performance of integrated high-grade durable flame retardant textiles Dependent on imports. In order to develop high-quality domestic flame-retardant products, instead of imports, we prefer and use aramid, flame retardant viscose fiber, synthetic aramid, flame retardant viscose properties of blended (Fang / viscous 65/35, 50/50) , Weaving and dyeing process research, developed from the raw material selection to spinning, weaving, dyeing, softening and a series of the best production process route, and through the key technologies of which research and development with durable flame retardant Aramid performance of the series, and achieved good results.
1 raw materials and product performance
1.1 raw material performance
Nomex fibers are aromatic polyamides and are poly-m-phenylene isophthalamide fibers. Has excellent heat resistance; good flame retardancy and chemical resistance; Has good mechanical properties: high breaking strength, high elongation, soft touch, high temperature does not soften, not melting, only carbonization, burning smoke Low concentration, low calorific value, washing resistance, good flame retardant performance after multiple washing, good dimensional stability and serviceability.
Flame retardant viscose is a silicate-containing cellulose fiber. With cellulose as the main body, its intramolecular formation of silicate molecular network and a large number of chemically bound water. Its physical and mechanical properties similar to ordinary viscose fiber, not only hygroscopic breathable and easy to stain, and acid and alkali resistant moth-eaten; compared with other flame-retardant fibers, low cost, pollution-free, can be processed into a variety of textiles. It is naturally biodegradable into a mixture of organic and inorganic soils. Carbonized into non-toxic SiO2 under combustion conditions. Fiber performance indicators in Table 1.
1.2 product performance
The product has a soft touch, good bulkiness, drapability, hygroscopicity and breathability and high strength, abrasion resistance, good fabric finish, color fastness, High profile flame retardant clothing, decorative fabrics of the quality requirements.
2 process
Focusing on the product surface style and enhancing the serviceability of the fabric, we developed a series of research and development plans for process and parameters of spinning and weaving, dyeing, finishing and other process equipment, and conducted repeated experiments, screening and confirming , To achieve the desired effect. The specific process is as follows:
Domestic flame-retardant textiles are mostly pure chemical fiber or cotton finishing products, ubiquitous hand feel hard, low strength, the case of fire and other defects melt drop, set durability, taking the overall performance of integrated high-grade durable flame retardant textiles Dependent on imports. In order to develop high-quality domestic flame-retardant products, instead of imports, we prefer and use aramid, flame retardant viscose fiber, synthetic aramid, flame retardant viscose properties of blended (Fang / viscous 65/35, 50/50) , Weaving and dyeing process research, developed from the raw material selection to spinning, weaving, dyeing, softening and a series of the best production process route, and through the key technologies of which research and development with durable flame retardant Aramid performance of the series, and achieved good results.
1 raw materials and product performance
1.1 raw material performance
Nomex fibers are aromatic polyamides and are poly-m-phenylene isophthalamide fibers. Has excellent heat resistance; good flame retardancy and chemical resistance; Has good mechanical properties: high breaking strength, high elongation, soft touch, high temperature does not soften, not melting, only carbonization, burning smoke Low concentration, low calorific value, washing resistance, good flame retardant performance after multiple washing, good dimensional stability and serviceability.
Flame retardant viscose is a silicate-containing cellulose fiber. With cellulose as the main body, its intramolecular formation of silicate molecular network and a large number of chemically bound water. Its physical and mechanical properties similar to ordinary viscose fiber, not only hygroscopic breathable and easy to stain, and acid and alkali resistant moth-eaten; compared with other flame-retardant fibers, low cost, pollution-free, can be processed into a variety of textiles. It is naturally biodegradable into a mixture of organic and inorganic soils. Carbonized into non-toxic SiO2 under combustion conditions. Fiber performance indicators in Table 1.
1.2 product performance
The product has a soft touch, good bulkiness, drapability, hygroscopicity and breathability and high strength, abrasion resistance, good fabric finish, color fastness, High profile flame retardant clothing, decorative fabrics of the quality requirements.
2 process
Focusing on the product surface style and enhancing the serviceability of the fabric, we developed a series of research and development plans for process and parameters of spinning and weaving, dyeing, finishing and other process equipment, and conducted repeated experiments, screening and confirming , To achieve the desired effect. The specific process is as follows:
3 spinning process to solve the problem
Aramid fiber is very fluffy, elastic, high elongation, and easy to accumulate when processing static electricity; flame retardant viscose fiber wet strength is low, wear resistance is poor, easy to static electricity, fiber brittle, the cohesion between fiber and fiber Poor, into a bar, gauze bulky and low strength, there is a spinning end of the high rate of defects in the spinning process focused on solving the following questions:
Aramid spinning process to maintain high humidity to avoid static electricity accumulation. Carding relative humidity of 60%; and Article 55% ~ 60%; spun yarn 45% to 50%.
Carding process Flame retardant viscose fiber wet strength is low, wear resistance is poor, the use of low speed, carding, small drafting, fast transfer process to reduce the damage to the flame retardant fiber and easy to start due to static winding phenomenon, Reduce neps, impurities and flocks. Relatively fluffy aramid fiber sliver, roll cotton cleaning process requires a higher pressure roller, to prevent the laps tear, coiler and bell guides and other devices at the device to maintain smooth and smooth, in order to reduce friction.
Aramid fiber length of 51mm, roving twist at 2.357 Twist / 10cm or so, should not be too high. Smaller basis weight and smaller roving twist factor are used to reduce the uneven drawing force of the spun yarn, thus reducing the thickness of the yarn and increasing the evenness of the yarn.
Appropriate increase in the twist coefficient of yarn, the general design of metric twist coefficient of about 383 more appropriate. Spinning with a large rear drafting gauge and a small rear draft multiple, drafting rubber roller with a soft roller to improve into yarn dry, to ensure the quality of yarn.
The use of automatic winder winding forming, yarn defects can be reduced, but also can be used without knot yarn to improve the quality of cloth.
As aramid fibers in the single yarn and strand are prone to distortion when the state, so the use of two fixed twist, that is, single yarn and strand at 85 ℃ in the twist 40
Min, in order to get a better v-twisting effect, to ensure that after the procedure does not produce a small yarn braid.
When spinning colored aramid yarns, the twist should be high to achieve better yarn strength. The twist of the plied yarn should be 70% of the twist of a single yarn, and the twisting should be the opposite of the single yarn to balance the torque.
4 product specifications and weaving process to solve the problem
4.1 Product Specifications
Flame-retardant clothing fabrics from taking performance requirements, require stiff, wear-resistant, beautiful; starting from the safety requirements, requiring flame retardant, high temperature. In the design of fabric specifications, the first consideration to meet the safety requirements. Fabric structure, weight, thickness, etc. will affect the fabric flammability. Such as high twist yarn, fabric structure closely, small permeability, difficult to fully contact with the surrounding air, burning difficult; similar fabric structure, the weight per unit area, the more difficult to ignite. Based on the above analysis, we developed the production of thick strands two on the left twill fabric, the basic effect of the expected.
Product Specifications: 19.6tex × 2 / 19.6tex × 2 315 / 212.5 119.5cm
4.2 weaving process to solve the problem
In warping, we should increase the weight of the tension ring appropriately to prevent the production of the pigtail yarn and ensure the warp beam winding density. When the sizing agent is selected, the appropriate slurry and sizing temperature are selected to ensure that the yarn fuzziness and sticking, the surface is smooth, the yarn adhesion is prevented, Yarn strength, yarn to maintain a certain degree of softness, elongation, so that the weaving process clear opening, broken head reduced; weaving, the appropriate increase machine tension, so that the fabric formation, clear lines.
5 dyeing process
As viscose fiber wet strength is much lower than dry strength, so in the wet process, as much as possible to loose processing or low tension processing. In addition, as the viscose fiber crystallinity, orientation, degree of polymerization and Young's modulus are relatively low, but also requires the use of loose processing. So we choose overflow dyeing machine dyeing.
5.1 production equipment
Overflow dyeing machine.
5.2 process
Gray cloth → singeing → desizing → dyeing → finishing
5.3 singeing, desizing
Due to the presence of irregular hair on the surface of the fabric, it is necessary to singe it, using two positive and two reverse, singeing grades should reach 3 to 4. Using alkaline desizing chemical and natural slurry, oil and wax have a good removal effect. The process conditions are as follows:
5.4 Dyeing
Due to the aramid fiber is not easy to stain, we only dye flame retardant viscose staining.
B-type reactive dyes. B-type reactive dyes to chlorinated triazine groups as the linker, the introduction of vinyl sulfone sulfate dye mother, so that both the advantages of both active groups, stable dyeing performance, high fixation rate, leveling Well, changes in dyeing conditions have considerable flexibility to adapt.
Dyeing prescription:
Type B Reactive Dye (o.w.f) /% 2
Na2SO4 / g · L-1 25
Na2SO3 / g · L-1 25
Temperature / ℃ 60
Bath ratio 1:10
Dyeing process see graph 1.
5.5 stereotypes
Kevlar blended fabric heat resistance is different from other synthetic fabrics. Due to the heat resistance of Kevlar fabrics, they are able to maintain dimensional stability above standard conditions. In order to improve the dimensional stability of the aramid blend fabric, the setting temperature should be 180 ℃, time 30s is appropriate.
6 Conclusion
The product through the selection of raw materials, the implementation of process programs and semi-finished products, such as the quality of the process-by-step strict control, optimization of process parameters, the amendment is not conducive to product quality factors to solve the flame retardant fibers in the spinning, weaving, dyeing and finishing process The technical problems before and after finished flame retardant finishing index GB8965-1998 flame retardant protective clothing to meet the standard requirements. Permanent flame retardant products obvious, high strength fabric, soft and comfortable, after repeated washing does not affect the flame retardant effect, flame retardant protective effect is ideal. The product favored by consumers, access to good economic benefits.
references:
[1] Jiang Hong. The progress of high temperature fiber (Ⅰ) 〔J〕. Textile Review, 2001; (1): 22 ~ 23.
[2] Jiang Hong. The progress of high temperature fiber (Ⅱ) 〔J〕. Textile Review, 2001; (2): 10 ~ 13.
[3] Cold pure Ting .Visil fiber high temperature flame retardant materials development 〔J〕. Industrial Textiles, 1999; (8): 14 ~ 16.
[4] cold Chun Ting, etc. New high temperature flame retardant viscose fiber [J]. Industrial textiles, 1998; (10): 35 ~ 37.
Xinxiang City Yulong Textile Co., Ltd. was established in 2002, over the years focused on the production of flame retardant, fluorescent-oriented variety of functional fabrics and security clothing. The company has afunctional fabric factory and protective clothing factory, as the domestic functional textile industry leader, Yu Long textile more groundbreaking integration of its fabric and clothing two factories of the advantages of resources, effort to build functional fabrics and clothing Station service center.