Antistatic textiles - clean clothing
The cost of electrostatic and particulate contamination damage by electronics and semiconductor manufacturers is quite alarming. It is known from statistics that the annual cost of damage caused by Electrostatic Discharge (ESD) is estimated to be as high as $900 million. Some experts believe that the actual losses will be even higher. Therefore, the requirements and quality of the environmental control room (clean room) are on the rise.
Since the air in the clean room usually has to be kept in a dry state of 45% relative humidity, it is easy to generate static electricity; there are two main types of static electricity induced in the semiconductor process, one is to cause particle pollution, in various clean rooms. The fifth source of particulate pollution sources, about 5%, the other is electrostatic discharge (ESD), which caused the failure rate, which accounted for the first place in the early failure sources of products, more than 50%; in order to overcome the electrostatic discharge Problem, many manufacturers have begun to study a variety of static control programs, including the machine tool and the electrostatic hazards generated by the human body.
The electrostatic discharge protective clothing for clean rooms must have: (1) static/static discharge, (2) low chance of generation of fine dust particles (low dust generation), (3) sufficient weaving strength, and (4) good durability, (5) resistance to specific chemicals and (6) wearing comfort and other characteristics.
At present, antistatic and dust-free clothes are mostly woven from artificial long fibers. These fabrics can be woven in a knitted, woven or spunbond manner. Polyester long fiber is the most important raw material for clean room fabrics. In order to impart a durable antistatic/static escape effect to the fabric, it is generally embedded in the weaving process (presumably 0.1 to 0.5% by weight of the fabric) of the conductive yarn. These conductive yarns are usually in the form of strips or grids on the finished fabric (3-10 mm, depending on the end use).
There are many kinds of antistatic fibers available on the market. The weaving of these fibers is usually done by adding a little conductive material to the fiber manufacturing process, which is obtained by the following two production methods:
1. Organic polymer fiber (mainly polyamine or polyester)
(a) Add a conductive substance additive (such as carbon black) during melt spinning.
(b) After melt spinning, a conductive material is used as a fiber for post-treatment.
2. Inorganic fiber (such as stainless steel fiber): Conductive fiber needs to be woven into cloth after spinning. The conductivity of fiber must be adjusted according to the type, amount and position of conductive material. Carbon fiber is the most commonly used conductive material. Materials, copper sulphide, copper iodide and other oxidized metals are also commonly used. The conductive material may be coated on the outer layer of the fiber by a similar coating process, or the composite fiber may be used to make the inside of the fiber contain a conductive material, or a part of the surface may be distributed on the surface to form two kinds of media inside the fiber, and the conductive material is usually The amount added is between 3% and 30%.