What is pva fiber?
Polyvinyl alcohol fiber (PVA fiber) is a kind of synthetic fiber made of high quality polyvinyl alcohol (PVA) with high degree of polymerization as raw material and special advanced technology.
Some characteristics of high strength fiber reinforced lightweight aggregate concrete!
Polyvinyl alcohol fiber is mainly characterized by high strength, high modulus, low elongation, wear resistance, acid and alkali resistance, good weather resistance, and cement, gypsum and other base materials that have good affinity and binding, and non-toxic, pollution-free, doing not damage human skin, harmless to human body, which is one of the new generation of high-tech green building materials. Pva is a kind of water-soluble high polymer, whose properties are between plastic and rubber. China is the world's largest producer of polyvinyl alcohol, followed by Japan, the United Kingdom and north Korea.
What is the synthesis and preparation of PVA fiber?
The average molecular weight of the raw material for pva fiber is 60000 ~ 150000. The thermal decomposition temperature is 200 ~ 220℃, and the melting point is 225 ~ 230℃. Polyvinyl alcohol fibers can be prepared by wet or dry spinning. Polyvinyl formal fibers were prepared by acetal treatment of the heat-treated polyvinyl alcohol fibers. The acetalization process is a process in which the tow is washed to remove sodium sulfate and then passed through the aldehyde solution (composed of formaldehyde, diluent water, sulfuric acid of catalyst and sodium sulfate, a swelling inhibitor) and then washed. The tow can also be cut into staple fibers, which are transported by air to the post-processing machine, and then acylation is carried out on the stainless steel net. In order to improve the properties of the fiber, the polyvinyl alcohol solution containing boric acid, a crosslinking agent, can be wet-spun, and the primary fiber is solidified in alkaline coagulation bath. After neutralization, washing, multi-stage high tensile and heat treatment, the filament with the strength of 106 ~ 115cN/dtex can be obtained.
What are the advantages of PVA fiber?
1. PVA fiber has good mechanical properties, high strength, high modulus, low elongation.
2. PVA fiber has strong acid and alkali resistance and chemical resistance.
3. PVA fiber has light resistance: the loss rate of fiber strength is low under long sunshine.
4. PVA fiber has corrosion resistance: the fiber can be buried in the ground for a long time without mildew, rot, moth.
5. PVA fiber has good dispersion: fiber does not adhere, good dispersion in water.
6. Fiber and cement, plastic and other have good affinity, and can be bonded strongly.
7. PVA fiber is non-toxic and harmless to human body and environment.
What can the PVA fiber be used for?
Pva fiber can be used in making canvas, waterproof cloth, press cloth, transport belt, packing material, work clothes, fishing net and cable for sea work. High fiber reinforced lightweight concrete pva modulus of elasticity can be used as the frame material of transport belt, the lining material of various rubber pipes, rubber cloth and rubber shoes, and also can be used to make tire cord. Because this kind of fiber is able to withstand the alkalinity of cement, and the bond and affinity of cement are good, which can replace asbestos to make the reinforcing material of cement product. It can be blended with cotton to make all kinds of clothes and indoor articles, and also produce knitwear. But the heat resistance is poor, the fabric is not crisp, and can not be washed in hot water. In addition, it is useful in non - woven fabrics, paper and other aspects.