Since the beginning of the use of dry carpets, the fibers used in the production of dry carpets include natural fibers such as cotton and asbestos, as well as synthetic fibers such as polyester fibers, polyamide fibers, polyacrylonitrile fibers, and polyolefin fibers. Early carpets used natural fibers, and now most of them use synthetic fibers.
1. Polyester fiber (Polyester)
It is a synthetic fiber composed of terephthalic acid (PTA) and ethylene glycol (EG). This kind of fiber has good strength, drying resistance, acid resistance, high hydrophobicity and dimensional stability, so it is used more in the production of dry blankets, but due to its poor resistance to steam and heat, its performance has been improving.
2. Polyamide fiber
Generally called nylon (Nylon), it is divided into nylon 6 and nylon 6.6 and others. The properties of the two are basically the same. The difference is that the melting point of nylon 6 is 215°C and the melting point of nylon 6.6 is 255°C. This kind of fiber has good abrasion resistance, steam heat resistance and strength, but poor acid resistance and dimensional stability, so most of them are not used alone but mixed with polyester fibers.
3. Polyacrylonitrile fiber
This fiber is a clothing fiber invented to replace wool. It was used as a fiber raw material for dry blankets in 1960. This kind of fiber has excellent resistance to steaming and heat, and it is quite effective to increase the life of the dry blanket under high temperature and high humidity.
4. Polyolefine fiber
This kind of fiber is rich in steam heat resistance, corrosion resistance and flexural resistance, and generally has a long service life at high humidity and high acidity below 130°C.
5. Cotton fiber
Cotton fiber has good water absorption and is inferior to synthetic fiber in heat resistance and acid resistance. Nowadays, this fiber is rarely used.
6. Other fiber raw materials
In order to make the dry carpet have other properties such as higher temperature resistance, humidity, antistatic and other properties, sometimes some special fiber raw materials such as glass fiber, metal fiber, and antistatic fiber are added to the fiber raw material.
It should be noted that Nomex (a kind of high temperature resistant nylon fiber) developed by the United States DuPont Company (DUPONT) is a special nylon fiber with a benzene nucleus. Its characteristics are dry heat resistance and steam heat resistance. The fiber is the best, but because of its high price, it can only be used in the joints, sutures, and base fabrics of dry carpets (nets). Table 1 lists the physical properties of fiber raw materials used in dry carpets for reference.
