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农用薄膜使用一段时间后,会发生变色,变硬、发脆等“老化”现象。这是为什么呢? 目前,常用的农用薄膜有两种:一种是聚氯乙烯薄膜,一种是聚乙烯薄膜。其中以前者为多。聚氯乙烯是以聚乙烯为基础,通过化学反应,使一个个氯乙烯分子互相连接起来,形成的长链结构。在生产时,为了提高农膜的性能,一般还要加入一定量的增塑剂等化学物质。农膜使用和存放过程中,受到光、温度、污物和化学药剂等因素的影响,就会使农膜分子结构逐渐
Agricultural film after use for some time, will change color, harden, brittle hair and other “aging” phenomenon. This is why? At present, there are two kinds of commonly used agricultural films: one is PVC film, one is a polyethylene film. One of the former is more. Polyvinyl chloride is based on polyethylene, through the chemical reaction, a vinyl chloride molecules connected to each other, the formation of long-chain structure. In production, in order to improve the performance of plastic sheeting, generally add a certain amount of plasticizers and other chemicals. Plastic film use and storage process, subject to light, temperature, dirt and chemical agents and other factors, will make the plastic film molecular structure gradually