How to identify plastic materials

1. PP=== Polypropylene, lightweight and tough, easy to process, good heat resistance, high impact strength at room temperature, high tensile strength, good rigidity, corrosion, difficult to paint, folding resistance up to millions Second, it has excellent electrical properties and large shrinkage. The cosmetic hose, PP.PE.PA is soft and bendable, has a hard waxy touch, slippery feel, and has a soft horny sound when knocking, while PS.ABS.PC.PMMA has no ductility and the knocking sound is crisp. The burning phenomenon of PP is roughly the same as that of PE. There may be a small amount of black ash. After the flame is extinguished, the smell of petroleum such as kerosene is smelled, which is non-toxic. 2. LDPE===soft rubber, high-pressure low-density polyethylene HDPE= ==Rigid soft rubber, low-pressure high-density polyethylene VHDPE===Super-hard soft rubber, ultra-high-pressure polyethylene is light and tough. Easy to process, good heat resistance, low temperature toughness, harder and impervious to water, but good abrasiveness, PE It is flammable and can still burn after leaving the fire. When burning, the flame is yellow and blue, and there is very little black. Near the flame, the plastic melts and drips, similar to the flow of a candle. After the flame is extinguished, there is more obvious paraffin wax Burning odor, non-toxic PE. The specific gravity of pp is less than water and floats in water. Most other plastics have a specific gravity greater than water and sink in water. 3. PC=== bulletproof rubber, colorless and transparent polycarbonate, impact strength is plastic First of all, excellent electrical properties, anti-aging, small shrinkage, stable product size, PC combustion phenomenon is close to PS but the burning speed is slow, it will slowly extinguish after leaving the fire, the flame is yellow, with black carbon beams, melting and bubbling during combustion After extinguishing, the smell of flowers and fruits. 4. PMMA===plexiglass (acrylic), polymethyl methacrylate has excellent transparency, can be dyed into various colors, is brittle and easy to crack, and has poor surface hardness , Easy to scratch. Good leakage resistance. The primary colors of PMMA and PS are transparent, but the combustion conditions are different. PMMA has no carbon beam escape, while PS does. When PMMA burns, the flame is light blue, the top is white, and it melts when burned Bubbles, giving off a strong smell of flowers and fruits and rotten vegetables, with microtoxicity. 5. PS===hard rubber (ordinary hard rubber), polystyrene, transparent and brittle HIPS===not broken glue, modified poly Styrene, elasticity. High toughness and high impact strength. ABS===ABS glue, super non-shattering, acrylonitrile-butadiene-styrene, easy to electroplating. High strength. Resistance to impact, cold, abrasion and corrosion. SAN (AS)===transparent non-breaking glue, styrene-acrylonitrile copolymer EPS===foamed rubber, foamed polystyrene PS primary color is transparent, HIPS primary color is milky white, ABS primary color is light ivory. PS The main difference between .HIPS and ABS is: PS is more brittle, HIPS and ABS have better toughness. When bending samples, PS is very brittle, HIPS and ABS are difficult to break, and the bending part is white. The original color of PS is transparent. Color, the original color of HIPS is milky white, and ABS is light tooth color. PS.HIPS. and ABS are both flammable, and they can continue to burn after removing the fire source. The flame is yellow with a thick black carbon beam, which escapes with the air , PS carbon beam is slightly less, when burning, the surface of the plastic near the flame is softened and not easy to drip, the surface of PS and HIPS will foam, ABS does not foam but is in a coked state, the smell of these types of plastics is different when they are extinguished Very large, PS has a monomeric smell of styrene, and ABS emits a pungent smell. Determine toxicity.