Abstract: Based on the changes in the 2009 national standards for safety anti-static protective clothing, this article puts forward higher requirements for safety anti-static textile standards and testing methods for anti-static series protective textiles. At the same time, corresponding processes are proposed for anti-static textiles to meet product quality requirements.
Keywords: Anti-static testing standards for safety protective clothing and textiles
1Foreword
The “Twelfth Five-Year Plan” for the printing and dyeing industry points out that functional textiles will be the growth point of the international market. With the advancement of science and technology and the improvement of the quality of life, consumers’ requirements for textiles and clothing are not limited to fashion. They have increasingly higher requirements for the functionality and comfort of textiles. They hope that textiles and clothing have special functional effects, such as antibacterial, Anti-microbial, iron-free, thermal insulation, etc., and have evolved from single-function finishing such as anti-bacterial and anti-wrinkle to multi-functional finishing to increase the added value of fabrics. Safety protection textiles are an important part of functional textiles, among which anti-static fabrics are also an important category of current protective clothing fabrics.
2 Anti-static textiles for safety protection
Safety protection has received more and more attention from society, and has become an important guarantee for safe production and rescue operations. The development trend of safety and protective textiles: focus on the development of multiple fiber optimal blending technologies and the development of high-tech fiber fabrics. Classification of protective clothing: general protective clothing, physical protective clothing, chemical protective clothing, anti-static clothing, high-voltage electrostatic protective clothing, and live work shielding clothing belong to the category of physical protective clothing.
3Quality standards for anti-static clothing and anti-static textiles
3.1 Quality standards for anti-static clothing
The original standard for anti-static clothing is: GB12014-1989 “Anti-static Work Clothing”; the new standard is: GB12014-2009 “Anti-static Clothing”
3.2 Comparison of quality standards for anti-static clothing
3.2.1 Comparison of technical requirements for physical and chemical properties:
Table 1 Original standard GB12014-1989
|
Breaking strength/N |
||
|
Thick material |
Thin material |
|
|
Radial |
≥780 |
≥490 |
|
Latitude |
≥390 |
|
Table 2 New Standard GB12014-1989-2009
|
Technical requirements |
|||
|
Formaldehyde content/(mg/kg) |
Direct contact with skin ≤75 |
Non-direct contact with skin≤300 |
|
|
pH value |
4.0～9.O |
||
|
Dimensional change rate/% |
+2.5～-2.5 (longitude and latitude) |
||
|
Air permeability/(mm/s) |
10～30 (coated fabric) |
>30 |
|
|
Color fastness to water/grade (discoloration, staining) |
≥3-4 |
||
|
Color fastness to dry rubbing/grade (discoloration, staining) |
≥3-4 |
||
|
Light fastness/grade (discoloration, staining) |
≥3-4 |
||
|
Breaking strength/N |
Meridian ≥ 780 (mass per unit area ≥ 200g/m2) Meridian ≥ 490 (mass per unit area < 200g/m2) |
Latitude≥390 |
|
Table 3 Original standard GB12014-1989
|
Grade A |
Grade B |
Test methods |
|
|
Amount of charged charge |
<0.6µc/piece |
Test according to the method specified in Appendix A (Supplement) of this standard.�� |
|
|
Washing resistance |
≥33.Oh |
≥16.5h |
Wash according to the method specified in Appendix B (Supplement) of this standard |
Anti-static clothing classification
|
Level |
Point-to-point resistance |
The amount of electrical charge carried by clothing |
|
A |
105<R≤10／ |
Q≤0.2µc |
|
B |
1057<R≤1011 |
0.2µc<Q≤O.6µc |
|
Test environment |
(20+5)℃, (35+5)%RH |
(20+5)℃, (35+5)%RH |
From the above standards, it can be seen that the number of protective textile testing items corresponding to the new standards has increased, and the assessment indicators have become more stringent.
4 Requirements for textiles in new standards
4.1 Anti-static clothing:
New GB12014-2009 “Anti-static Clothing” inspection items: fabric point-to-point resistance, fabric formaldehyde content, fabric pH value, fabric dimensional change rate.
4.2 Anti-static textile testing standards:
GB/T12203.1-2008 Evaluation of electrostatic properties of textiles Part 1 Electrostatic voltage half-life;
GB/T12703.2-2009 Evaluation of electrostatic properties of textiles Part 2 Charge area density;
GB/T12703.3-2009 Evaluation of electrostatic properties of textiles Part 3 Charge quantity;
Most of the technical indicators in GB12014-2009 “Anti-static Clothing” are for textiles, and the detection methods are more detailed.
4.3 Main technical requirements and changes in the new standard
Fabric point-to-point resistance, fabric formaldehyde content, fabric pH value, fabric dimensional change rate, fabric breathability, fabric color fastness to water, fabric color fastness to dry rubbing, fabric light color fastness, fabric breaking strength, clothing charge capacity, Clothing sewing, clothing size change rate.
The inspection items include fabric point-to-point resistance, fabric formaldehyde content, fabric pH value, fabric dimensional change rate, fabric air permeability, fabric color fastness to water, fabric color fastness to dry rubbing, fabric light color fastness, clothing dimensional change rate, Garment sewing. The testing methods and technical requirements for the electrical charge of clothing have been changed. There are 12 main technical requirements in total, of which 9 are for fabrics. Compared with the original standard GB12014-1989 “Anti-static Work Clothing”, 8 more technical requirements are added for fabrics.
4.4 Description of changes
The grading standards and technical requirements for the electrical charge of clothing have been modified from the old standards of Class A and B, which were both <0.6µc/piece, to Class A <0.20µc/piece, and Class B 0.20-0.60µc/piece. ; Unify the different washing times of the old standard A and B levels into 33 hours of washing, including 9. Oh of washing, 8. Oh of rinsing/time, and repeated rinsing 3 times; tested environmental temperature and humidity! The relative humidity of the old standard has changed from <40% to (35±5)%; the technical requirements such as test and depth have changed to a certain extent; the seam strength is included in the drum inner diameter requirements of the technical friction device for garment sewing , and the technical requirements for strong force have changed from 98Nl to 100N; it is stipulated that the distinction between thin and thick materials is divided by unit mass area.
4.5 Anti-static clothing fabric printing and dyeing process
At present, the anti-static methods for textiles include applying antistatic agents, stainless steel fiber blends, organic conductive filament inlays or organic conductive fiber blended textiles.
Take the printing and dyeing process of anti-static and three-proof multi-functional finishing outdoor protective fabric (national flag red anti-static clothing fabric) as an example:
Variety: CVC32/2×32/2100×5363″ (its C60/T40), with anti-static wire embedded in the longitude and weft directions.
Processing process:
Turning seams → singeing → deboiling and bleaching → mercerization → polyester dyeing → reduction cleaning → overdyed cotton → protective finishing → inspection → storage.
4.5.1 Process prescription and conditions:
①Deboiling and bleaching: scouring (double-layer net) 98-102℃ 90min
NaOHll-12g/L
Refining agent 8-10g/L
②Bleaching: H2025-6g/L
Stabilizer 6g/L
Chelating dispersant 1-1.5g/L
③Dyeing: National flag red (big red) uses reactive/dispersed (omitted)
④Protective finishing: Use equipment shaping machine
Dip prescription:
GA-290g/L
Synergist 10g/L
Process conditions: 180℃, 40 seconds
Anti-static index test method standardThe adaptability is different, such as: half-life method, frictional charging voltage method, charge surface density method, point-to-point resistance, clothing charged amount method
4.5.2 Process points:
① This process uses low-alkali scouring to prevent damage to organic conductive filaments or anti-static fibers due to excessive alkali concentration and high temperature conditions, affecting the anti-static effect.
② During the processing of anti-static textiles, the process should be strictly operated to strive for first-time success, avoid repairs, reduce the time of contact with chemicals such as alkalis, and ensure the anti-static effect.
5 Conclusion
Our company currently produces more than 60% of various protective textiles, of which textile fabrics used for anti-static clothing account for about 25%. According to customer requirements, the anti-static indicators tested using the point-to-point resistance method have reached Level A or Class B standard requirements.
According to the requirements of safety protective clothing, our company selects reasonable process conditions for fine processing of fabrics. To meet the needs of various types of safety protective clothing. The main measures to improve the effectiveness of protective textiles are as follows:
Increase the conductive yarn content of the fabric; use cross-conductive black yarn instead of gray yarn and white yarn to improve the conductive properties of the fabric; increase the strength of the conductive yarn; use specially processed conductive yarn; apply good antistatic agents in the finishing process, such as moisture wicking Use anti-static finishing agent to improve the anti-static function.
In short, due to changes in the national standards for protective clothing promulgated in 2009, printing and dyeing companies must respond to the new standards and adopt innovative and meticulous technical measures to produce safety protective textiles that meet the new standards.
Author: Shanxi Caijia Printing and Dyeing Ma Xuaya Niu Hongqiang Chai Huazhen
References:
[1]GB12014-1989 “Anti-static Work Clothing” [S].
[2]GB12014-2009 “Anti-static Clothing” [S].
[3] Yang Wenfen. Proceedings of “2011 China Safety Protection Textile and Apparel Industry Innovation and Development Forum” Standards and Testing Technology for Safety Protection Textiles, [C] Beijing: China Industrial Textiles Industry Association 2011.
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