国产精品自产拍在线观看首页_国产美女遭强高潮开双腿_亚洲日本文字天天更新_国产美女高潮久久久久白浆,国产精品亚洲一区二区三区天天看|久久久综合九色综合|欧美日韩精品视频一区二区在线播放|亚洲小视频在线观看

Introduction to the intention of engineering plastics to participate in heat stabilizers and the primary use object of heat stabilizers: heat stabilizers belong to one of the stabilizers, which is an additive that can make the quality of plastics not deteriorate under high temperature environment. Because the thermal stability of PVC is very poor, while other plastics have good thermal stability within the temperature range of molding processing. Therefore, the primary use object of heat stabilizer is PVC.

Introduction to the intention of engineering plastics to participate in the heat stabilizer: it is well known that the molding of plastic products is obtained through thermal processing. When resins and other materials are heated, softened, melted and molded, they must undergo high-temperature testing. For example, PVC resin, because the processing temperature is very close to its decomposition temperature, when it is processed at 160 ~ 200 ℃, PVC will undergo severe thermal degradation, macromolecular chain fracture, product discoloration and function degradation. In order to stop this phenomenon, it is necessary to participate in the heat stabilizer, otherwise, this product cannot be used.

Source: Jiangmen engineering plastics http://www.lyx0.com/