How to identify plastic materials 1 . PP===Fast Polypropylene, Polypropylene Lightweight and tough, easy processing, good heat resistance, high impact strength at room temperature, high tensile strength, good rigidity, corrosion, difficult to paint, bending up to millions of times, excellent electrical properties, high shrinkage. PP.PE.PA is soft and bendable, with hard wax-like touch, creamy feel, and soft horny sound, while PS.ABS.PC.PMMA is non-ductile and percussion sound is crisp. PE is generally the same, there may be a small amount of black pods, after the flame is extinguished, it smells like kerosene like petroleum, no toxicity. 2. LDPE===soft rubber, high pressure low density polyethylene HDPE===hard soft rubber, low pressure high density polyethylene VHDPE===Superhard soft rubber, Ultrahigh-pressure polyethylene Light and tough. Easy to process, good heat resistance, good low temperature toughness, hard, impervious, but good grind, PE is flammable, can still burn after leavi