Plastics of different materials have different melting points:
Polypropylene: The melting point temperature is 165°C—170°C, the thermal stability is good, the decomposition temperature can reach above 300°C, and it begins to turn yellow and deteriorate at 260°C in the case of contact with oxygen, and has anisotropy during low-temperature molding. It is easy to be warped or twisted due to molecular orientation, and has good folding performance. The resin particles have a waxy texture. The average water absorption is less than 0.02%. The allowable moisture content of molding is 0.05%. Therefore, drying is generally not performed during molding. It can be dried at about 80°C for 1-2 hours, and its flow properties are sensitive to temperature and shear rate during molding.
Polyoxymethylene: It is a heat-sensitive plastic with a melting point of 165°C, which will seriously decompose and turn yellow at a temperature of 240°C. The residence time at a temperature of 210°C should not exceed 20 minutes. In the normal heating range, it will decompose if it is heated for a longer time. , After decomposition, there will be a pungent odor and tearing. The product is accompanied by yellow-brown stripes. The density of POM is 1.41—1.425. –5 hours.
Polycarbonate: starts to soften at 215°C, starts to flow above 225°C, melt viscosity below 260°C is too high, and the product is prone to insufficiency. The molding temperature is generally between 270°C and 320°C. If the temperature exceeds 340°C, decomposition will occur, and the drying temperature The temperature is between 120℃—130℃, and the drying time is more than 4 hours. The polycarbonate resin is generally colorless and transparent particles.
Post time: Oct-22-2022