Keywords: textiles; antistatic; testing methods
Abstract: This paper outlines the development of antistatic technology of textiles, and gives a summary of the testing and evaluation methods of the antistatic properties of textiles.
Keywords: textiles; antistatic; testing and evaluation methods
In the past decade, China's textile antistatic technology has developed rapidly, in addition to the application of professional workplace antistatic overalls, ultra-clean overalls, the army, the armed forces of the regular clothing, training uniforms, etc. in order to prevent static interference and the possibility of static hazards are also used in antistatic technology, and even general civilian textiles, such as cashmere sweater knitwear also added an organic conductive fibers.
Textile quality testing organizations often receive a variety of enterprises to test antistatic product samples. With the development of antistatic technology, the state and industry sectors in recent years have revised and released a number of textiles and textile clothing antistatic test methods of the new technical standards. In this paper, combined with practical experience, the textile antistatic technology and test and evaluation methods are summarized below.
1 textile antistatic technology
1.1 The hazards of static electricity
Static phenomenon is mainly due to object friction (contact - separation) or induction. Generate static electricity after the same sex charge mutual repulsion, anisotropic charge mutual attraction, thus causing production and life in the electrostatic interference. Life due to electrostatic adsorption, with anisotropic charge of dust will be attached to the surface of the fabric, tops and pants for different materials, different polarity of the charge caused by mutual attraction, the clothes and clothes entangled with each other, the clothes of the human body entangled in the phenomenon. In addition to the above general hazards, textiles and clothing, electrostatic phenomena may cause significant losses of the main hazards are: 1) lead to large-scale integrated circuits and other microelectronic devices damage. With the miniaturization of integrated circuits, the static voltage generated by clothing due to friction is enough to make the integrated circuit breakdown. For example, MOS circuits are resistant to breakdown voltage of only a few dozen volts, while the general clothing due to friction generated by the static voltage can reach tens of thousands of volts or even higher. 2) lead to oil combustion. For example, there have been two tankers due to static electricity in a month of fire; 3) lead to pyrotechnic products (detonators, explosives, etc.) of the explosion. For example, the friction generated by the explosives handling people to take off their clothes led to clothing with hundreds of thousands of volts of static voltage, which triggered the handling of pyrotechnic explosions. The above three most harmful static disasters are related to textiles.
1.2 Traditional antistatic methods
Traditional textile antistatic processing methods are:
1) the use of antistatic fibers. Antistatic fibers have high moisture absorption and balanced moisture return rate, can adsorb water molecules in the air, so that the textile has a better antistatic properties, that is, not easy to produce static electricity, the static electricity has been generated is relatively easy to escape.
2) Apply antistatic agent. Antistatic mechanism with antistatic fiber.
3) Stainless steel fiber blend. The use of metal fibers good conductive properties so that the static charge has been generated easy to escape.
4) organic conductive filament embedded or organic conductive staple fiber blending. Antistatic mechanism is similar to stainless steel and other metal conductive fibers, that is, to play an easy to cause the charge to escape the effect. For organic conductive fibers, not only the use of carbon black as a conductive material for the gray products, but also metal oxides, metal carbides as a conductive material for the white or nearly white organic conductive fibers.
1.3 antistatic new technology
In recent years and the emergence and promotion of two types of conductive fibers, which can be applied to the antistatic processing of textiles.
1) Silver-plated fibers or filaments. As silver fibers have good antibacterial and conductive properties, so the textiles contain less silver-plated fibers (1% or so) on the antibacterial function and good antistatic function, if the silver-plated fibers used to make the formation of conductive network structure within the textile and the structure of the relatively dense, but also has a good electromagnetic shielding effect. For the anti-static function, due to the conductive properties of silver fibers, electrostatic charge dissipation ability is stronger than organic conductive fibers, so in general, the anti-static effect is better than organic conductive fibers.
2) conductive polymer materials. Such as polyaniline, polypyrrole, polythiophene and so on. These conductive polymers are only in recent years began to enter the engineering applications. Now d conductive polymers can be made into fibers or coatings, which have a low resistivity and can be used as a new raw material for antistatic processing of textiles.
2 antistatic product standards and test methods
The evaluation of textile static performance indicators are mainly used charge surface density, friction charged voltage and induced voltage half-life.
2.1 Standard Status
The new GB/T 12703 textile electrostatic test method standard is divided into seven parts: three parts have been implemented: GB/T 12703.1-2008 "textile electrostatic properties of the evaluation of the first part of the static voltage half-life"; GB/T 12703.2-2009 "textile electrostatic properties of the evaluation of the second part of the charge GB/T 12703.2-2009 Evaluation of Electrostatic Properties of Textiles Part 2 Charge Density; GB/T 12703.3-2009 Evaluation of Electrostatic Properties of Textiles Part 3 Charge Quantity; The other four parts are under revision: Part 4: Resistivity; Part 5: Friction Charged Voltage; Part 6: Leakage Resistance of Fibers; Part 7: Dynamic Static Voltage. Textile production process and clothing wear the use of static electricity and the degree of interference can be measured through the seven parts of the static electricity test method.
At present, in addition to the implementation of the national standard GB/T 12703 textile electrostatic test methods, there are some industry standards are also implemented at the same time. Such as: FZ/T 01043-1996 "textile materials electrostatic properties of dynamic static voltage determination", FZ/T 01059-1999 "fabric friction electrostatic adsorption determination method", GB/T 18044-2008 "carpet static habit evaluation method line straight test" and so on.
2.2 Textile products antistatic product standards
Generally according to the antistatic textile use of different occasions, each industry also has different technical requirements. Therefore, the product standards and the corresponding technical requirements of different industries, mainly: military, special industries, civil and so on. Our country according to the need to develop a special industry services GB 12014-2009 "anti-static clothing", GB/T 24249-2009 "anti-static clean fabrics", GBT 22845-2009 "anti-static gloves" and other standards, and as a labor protection supporting GB/T 23464-2009 Standard for Anti-static Woolen Knitted Clothing" and other related product standards. Table 1 lists the test methods and technical requirements of the above standards.
Table 1: Antistatic products and corresponding test methods and technical requirements
Product standards
Test items
Technical requirements
Test methods
Environmental requirements
GB 12014-2009 Anti-static Clothing
Point to Point Resistance
Class A 1×105～1×107Ω
Class B 1×107～1×1011Ω
GB 12014-2009 Appendix A
Temperature：（20±5）℃
Relative Humidity：（35±5）%
Charged Charge
Class A＜0.2 μc /piece
Class B <0.2～0.6 μc/piece
GB 12014-2009 Appendix B
GB/T 23464-2009 Protective Clothing Anti-static Woolen Knitted Clothing
Powered Charge
<0.6 μc/piece
GB 2014- 1989 Appendix B
Temperature: (20±2)℃
Relative humidity: (35±5)%
GBT 22845-2009 Anti-static Gloves
Powered charge
<0.6 μc/pc only
Method E of GB/T 12703
GB/T24249-2009 Antistatic Clean Fabrics
Surface resistivity
1×105～1×1011 Ω/
GB/T 12703
Temperature: (23±5)℃
Relative humidity: (12±5)%
Friction voltage
Level 1: 200 V
Level 2: 1000 V
Level 3: 2500 V
Appendix B of GB/T24249-2009
Through the analysis of Table 1, it can be seen that textile antistatic testing is more stringent requirements on the environment, which is because temperature and humidity have a relatively large impact on the index of antistatic. This is because the temperature and humidity on the antistatic index is relatively large, and directly affects the accuracy and repeatability of the test results. Therefore, it is usually necessary to meet the requirements of the test conditions in the constant temperature and humidity laboratory for testing.
2.2.1 "Anti-static Clothing" new standard analysis
The new version of the "Anti-static Clothing" standard, an increase in raw materials that is the technical requirements of the fabric; increased one-piece clothing styles; increased sewing stitch requirements; clear that the lining should be used in anti-static fabrics. Antistatic performance, reference to the European standard and the American standard increased clothing, fabric surface resistance of the technical requirements; in order to facilitate the user to choose clothing according to different occasions, the anti-static performance of clothing according to the technical indicators are divided into levels. In the physical and chemical properties added a number of indicators. Increased clothing, fabric air permeability and moisture permeability, shrinkage, water color fastness, color fastness to dry friction, formaldehyde content of the test. In Appendix A, the test method of surface resistance of garments and fabrics is stipulated; in Appendix B, the test condition of electrically charged charge of garments and fabrics is modified from the original requirement of relative humidity less than 40% to (35±5) %. In Appendix C on the washing requirements were revised, unified provisions of the washing time of 33 h.
In the test method standards, specifically formulated a test method with GB12014-2009 supporting standards GB/T 23316-2009 "work clothes antistatic properties of the requirements and test methods
2.2.2 "anti-static clean fabrics" standard analysis
The standard is developed for specific industries anti-static fabrics standards. Applicable to electronics, semiconductor, pharmaceutical, food and other industries in the clean room and related controlled environments used to make clean clothing and other products of the fabric. With the conventional anti-static fabric requirements are different: its test environment requirements for the temperature (23 ± 5) ℃, relative humidity: (12 ± 5) %; the basic physical increase in the abrasion resistance index requirements, and the use of GB / T 21196.3 method of standardized abrasion resistance index test; static performance requirements must be consistent with the surface resistivity and friction voltage requirements, and provides for static performance of the washing grading test In Appendix B, the test method of surface resistivity is stipulated; the clean performance of the product is controlled by two indexes, namely, dust generation rate (p/min) and air particle filtration efficiency (%). In Appendix C and Appendix D specify the dust rate and air particle filtration efficiency test methods.
2.2.3 "protective clothing anti-static wool knitted fabrics" standard analysis
In order to test the anti-static fiber with anti-static fibers and wool, cotton, acrylic and other fibers blended or interwoven and made of needle knitted garments antistatic properties, the state promulgated a new standard GB/T 21244-2009 "Protective Clothing Anti-Static Wool Knitted Fabrics". This standard has clear provisions on the model of washing machine, pH value of detergent, washing process and program in Appendix A. The washed garments are tested according to the method specified in Appendix B of GB 12014-1898, which stipulates that the electrified charge of the whole garment should not be greater than 0.60 μc/piece, and the physical and chemical properties require that the pH value should be controlled between 4.0 and 8.5, which is different from that of GB 18401-2003 for the assessment of the pH value by A, B and C. The test is conducted in accordance with the requirements of Appendix B of GB 12014-1898. Batch clothing testing of unqualified items for physical and chemical class A and appearance of class B division.
3 antistatic performance test problems
In the textile antistatic performance testing practice, static voltage half-life method, charge surface density method, friction charged voltage method and other different static test methods to measure the value of the value obtained between the general does not have a direct relationship between the equilibrium value. In some antistatic product testing requirements, customers require the use of GB/T 12703 in more than two test methods to detect product quality. The data measured by the two methods may be contradictory, and it is impossible to determine whether the antistatic performance meets the requirements, for example:
A antistatic textiles are often embedded in metal conductive fibers during the weaving process. These conductive materials are usually found in strips or lattice styles on the finished cloth. For such products, some customers require the use of charge density and static voltage half-life at the same time to assess the antistatic performance, there will be a very low charge density in line with the requirements of the technical specifications, but the static voltage half-life can not be reduced.
B. Single-sided laminating products using static voltage half-life test of antistatic performance, there are metal laminating surface test voltage, half-life are shown zero, in line with the technical specifications; while the reverse side of the voltage> 2 KV, half-life> 60 S, can not meet the technical requirements of antistatic. The positive and negative sides of the use of different processes, antistatic performance has a great difference.
The above shows that the evaluation of antistatic performance of textiles should be based on the nature of the fabric and the use of different test methods and test items, and test items with the different products, the significance of the characterization is also different. Therefore, try to avoid using a single indicator for the evaluation of antistatic properties of textiles. Should be based on the needs of different industries and related controlled environment used in the anti-static textiles, testing its anti-static properties, the correct choice of suitable anti-static product standards, corresponding environmental requirements and testing methods.
4 Conclusion
With the large number of integrated circuits and other microelectronic devices that are susceptible to electrostatic losses, the hazards caused by static electricity are becoming increasingly prominent. Therefore, antistatic is a common feature of textiles and should be continuously developed. In order to overcome the problem of electrostatic discharge, many researchers are researching and developing composite antistatic textile materials with the following characteristics: durable antistatic, fast static escape, low chance of generating microdust particles, good resistance to corrosion and comfort performance, and the types of antistatic products are constantly being developed and improved. At the same time the standard of antistatic products and the corresponding test method standard should also be continuously improved. Strength technology