Plastic Packaging

Plastic Bottle Cap Manufacturers, Custom Pet Bottles, Pet Bottles suppliers.
Made by: https://www.plastic-bottle-manufacturers.com/plastic-bottle-cap-manufacturers/

Thus, in the production of medicinal PET bottles, intrinsic viscosity of the raw materials, the crystallization temperature, cooling rate, and other process data alignment effect is particularly important. This is because the polyester material is a crystallizable polymer, the crystallization rate is small, only 6μm / min (max). Through process control crystallization conditions such as temperature and cooling rate, the polyester bottle into a non-crystalline or crystalline, and can change the crystal type and quantity. Crystallinity of the polyester requirements generally about 30%. At or slightly above the glass transition temperature slightly below the melting point, the crystallization rate of the polyester is small, crystallization takes a long time, at a temperature of about 175 ℃, the crystallization time is much shorter. In short, only by heating a crystalline polyester, the crystallization process is slow, it is possible to form a larger spherulite crystal, which refracts the light, so that white goods, and brittleness. Furthermore, with increasing the crystallization rate of the polyester decreases their Ⅳ. Ordered molecular orientation of the polyester can promote crystallization, the formed crystals called strain-induced crystalline, the grain is small, the light is not refracted, so oriented polyester article is transparent. If the sample of polyester partially crystalline orientation as heat setting to make further crystallized sample remains transparent. Therefore, the crystal orientation of the impact and stretch blow molding of PET bottles during the key factor to ensure performance. If the hot filling of bottles with bar-type sterilization, but also on the part of the crystalline polyester for heat setting, the further crystallization so in order to improve heat resistance.
2, polyester material dehumidifying and drying.
Because the processing of the polyester, wherein the moisture contained in the hydrolysis process will chemically react with the polyester melt rapidly consumed, i.e. water bubbles in the article. Hydrolysis will reduce the intrinsic viscosity of the polyester melt, but also affect the mechanical strength and performance of products, while the polyester raw material is a hygroscopic polymer, it should be subject to stringent and dried prior to processing to excess moisture content of less than 0.005%. Polyester raw materials to be used desiccant drying system to dry.