Fire retarding properties of pvc granules(pvc compound)
欄目:Industry News發(fā)布時間:2021-06-03 15:19
PVC is an inherently fire resistant plastic, the only exception among the general-purpose plastics, since it contains more than 50% of chlorine. When PVC products are burned, hydrogen chloride gas resulting from thermal cracking slows down t...
PVC is an inherently fire resistant plastic, the only exception among the general-purpose plastics, since it contains more than 50% of chlorine.
When PVC products are burned, hydrogen chloride gas resulting from thermal cracking slows down the continuous combustion reaction and prevents burning progress by warding off the PVC product surface from oxygen in the air. The gas is also detectable by its – highly unpleasant - odour at concentrations well below those that could be harmful to health. This feature allows early detection of a fire. Gaseous hydrochloric acid is, for example, much less hazardousthan carbon monoxide, which is narcotic and has no smell and can rapidly lead to paralysis and death.
Other advantages of PVC are that it releases less combustion heat than other plastics - hence contributes less to maintaining and spreading fire – and produces no or very few flaming droplets or debris. Burning PVC yields an expanded carbonaceuous structure usually called ‘intumescence’. This structure forms a thermal barrier protecting underlying parts. In some cases, such as pipes, PVC can even prevent fire spreading by blocking the orifices through walls or floors. Oxygen index of various plasticsSince PVC is highly fire resistant, it is widely used in exterior construction materials such as window profiles, siding boards, or interior housing materials, such as wall-covering and flooring. It is also used in industrial facilities such as tanks, ducts, parting strips, or for sign boards, corrugated boards, and cable coverings. There may be many ways of evaluating the fire retarding properties, but the oxygen index can be used for the evaluation with a comparatively high precision and reproducibility of the results. It represents the minimum oxygen concentration required for the test piece to continue burning in mixed gas of oxygen and nitrogen. When the value is higher, the fire retarding property is higher. Since the oxygen concentration in the air is 21%, a plastic with an oxygen index greater than 22 has self-extinguishing property, while a plastic with oxygen index smaller than 21 is flammable.
Fire resistant properties can also be given to olefin plastics such as PE and PP by cross-linking treatment or by adding large quantities of fire retardants, but it would be difficult for these plastics to compete with the versatility of flexible PVC products whose softness can be controlled with ease and which can be easily recycled.
Since Wuxi Jiahong Plastics Technology Co., Ltd. (originally Xishan City Plastic I Factory) transformed into PVC granulation product industry in 1988, for nearly 30 years of production and market development, we have accumulated mature PVC mixture production experience and gained a higher market share and reliability. Owning a full set of high production yield granulation system and multiple sets of granulation equipment of various types which are introduced from Battenfeld, various of transparent and colored hard and soft PVC granules (PVC compound) material we produced can meet many production process requirements, such as injection molding, extrusion, blow molding and injection stretch blow molding and so on, with the annual production capacity of over 10,000 tons. The scale of production and the advanced production techniques ensure the stability and high-quality of the product performance. The major processing functions of the existing rubber in our company are: food & beverage and pure water packaging containers, pet food and leisure suppliers and industrial blow molding packages, daily extract supplier containers, integrated circuit (IC) packaging tubes, supermarket shelves, bathroom furniture decorative accessories, heat shrinkable packaging and labeling film, pipeline and pipe valve environmental engineering accessories, motors (trains) vehicles series of specialized plastic accessories, one-off medical equipment components and peripheral accessories(rigid & clear PVC granules), electrical engineering switches panel isolative and flame-resistance products etc. With the advanced production equipment, excellent product quality, high-qualified work force, scientific and strict management and perfect services, our company has been the highly-trusted partner of other well-known manufacturers of plastics and relevant industries.