5. Rigid PVC has good tensile, bending, compressive and impact resistance, and can be used alone as a structural material.

6. The softness, elongation at break and cold resistance of soft PVC will increase, but the brittleness, hardness, and tensile strength will decrease.

7. Polyvinyl chloride has good electrical insulation properties, can be used as low frequency insulation material, and its chemical stability is also good. Due to the poor thermal stability of polyvinyl chloride, long-term heating will cause decomposition, release HCL gas, and make polyvinyl chloride discoloration, so its application range is narrow, and the operating temperature is generally between 15 and 55 degrees.

8. PVC is incombustible and extinguishes immediately after leaving the fire, but when burning, the upper end is yellow, the lower end is green, and there is white smoke. When burning, the rubber material becomes soft and emits a pungent odor of hydrochloric acid. PVC is slightly toxic, but it also has food grade PVC. The English abbreviation of PVC polyvinyl chloride. There are both hard and soft.

9, divided into two categories of toxic and non-toxic. The hard plastics used in domestic life are basically PVC. Such as water pipes and wire sheaths. PP polypropylene. Plastic carbonated beverage bottles are made of PP sheets (Coke) and can withstand a little pressure. In addition, there is a tool box bottom and cover that are integrated, and can be opened and closed repeatedly without hinges. This material must be PP sheet.