FTTS-FA-003 Electromagnetic Shielding Textiles

As everyone knows, many electronic devices such as cellular phones, computers and microwave ovens release electromagnetic waves. Based on the findings of studies and researches conducted by many domestic and international scholars and experts, it is very likely that electromagnetic wave harms human body but the problem is very easily neglected by most people.

Electromagnetic shielding textiles protect human body from such harm. They can be classified into three types:
1. Hybrid woven fabrics achieve electrical conductivity through twisting metallic fibers (which is thinner than human hair) with natural fibers or wrap natural fibers in metallic fibers to form electrically conductive composite yarns.
2. Conventional woven fabrics achieve electrical conductivity by undergoing finishing treatment processes such as electroless plating, sputtering and evaporation deposition. These processes fix electrically conductive metal particles on the surface of the fabrics to turn the fabrics into electrically conductive metallized fabrics.
3. Add conductive particles to polymers to form conductive filaments which are then spun into yarns and in turn woven into fabrics. The electromagnetic shielding effectiveness of such fabrics will not diminish even after many launderings.

Electromagnetic Shielding Textiles are usually graded into two classes – the Professional Use and the General Use. With current technology in Taiwan, general-use Electromagnetic Shielding Textiles can possess a shielding effectiveness (SE) up to a level of 30dB, while professional-use products can possess a shielding effectiveness from at least 30dB up to 50dB or higher.

This criterion is applicable to textiles in all forms, including woven, knitted, coated/laminated fabric and non-woven. To consider the durability, the pretreatment, ex: repeated laundering, weathering, may be required

3.1 The functional requirements in the test method are classified according to product end-use.

3.1.1 Class I--Professional use

for medical devices, safety uniform , shielding material for electronic component, assembly equipment and other application.

3.1.2 Class II--General use

for casual wear, uniforms (computer and telecom company), aprons, maternity dress,orprotective covers for consumer electronic products and other application.

(1) Class I － Professional use

(2) Class II － General use

Remark1：

SE： Shielding Effectiveness（dB）

ES： Percentage of Electromagnetic Shielding (%)

Remark 2：

Shielding Effectiveness (dB) can be calculated and converted into Shielding Effectiveness (%). Please refer to the Appendix Table for details.
1.2 General requirement for pretreatment