Simple identification of plastics
DATE：2022/7/12 8:43:14 / READ： / SOURCE：This station
Simple identification of plastics
The identification of raw materials used for forming baby products is under the condition that the manufacturer does not have complex analytical instruments. Generally, simple methods such as detecting density, burning and solubility are used to judge plastic varieties. The detection technology of density value is stipulated in gb1033 standard. See the table for distinguishing and comparing the characteristics and properties of several commonly used plastic products. Plastic name density /g*em-3 appearance characteristics combustion characteristics are used in solution. Hollow board production line www.handern comPolyethylene (PE) low density 0.910~0.925 products are milky white, translucent, waxy, flexible and greasy when touched by hand; It can stretch slightly and burn easily. It continues to burn after leaving the fire. The upper part of the flame is yellow and the lower part is blue; Melting and flowing, smoke-free, the smell is similar to that of a candle, it can float on the water surface, sink in 58.4% ethanol solution, blow molded film hollow injection products, water pipes and daily necessities, medium density 0.926~0.940, high density 0.941~0.965 Hollow board production line www.handern com
Polypropylene (PP) 0.905 (23 ℃) is white, translucent, waxy, harder than PE and more transparent than PE; Low permeability, easy to burn, and keep burning away from the fire. The upper part of the flame is yellow and the lower part is blue; The material melts and flows, emitting black smoke, with petroleum smell, and can float in 58.4% ethanol solution and water. Woven bags, ropes, fishing nets, medical equipment, filter cloth, waterproof cloth, cotton products, flanges, bicycles, auto parts and daily necessities, etc Hollow board production line www.handern com
Polyvinyl chloride (PVC) rigid 1.35~1.45 pure PVC products are yellow and transparent, which is better than PE and pp. they are not as easy to burn as PS. they are extinguished immediately after leaving the fire. When burning, the upper part of the flame is yellow, the lower part is green, and there is white smoke; There is a pungent sour taste in salt saturated solution and water, sinking plates, sheet and tube pump bodies, profiled materials and other thin-film wire sheaths, soles, daily necessities and other soft 1.16~1.35 hollow plate production line www.handern com
Polystyrene (PS) 11~3.6 is colorless and transparent, similar to glass products, brittle and easy to crack. It emits a metal like sound on the ground - flammable, and continues to burn after leaving the fire. The flame is orange yellow; When the material is softened, it bubbles, emits black smoke, sinks in the water, and can float in calcium chloride aqueous solution, cups, plates and other tableware, stationery and educational supplies. Parts for instruments and electrical appliances Hollow board production line www.handern com
Combustion characteristics of plastic products: by observing the phenomenon caused by the combustion of plastic products, the varieties of plastics can be identified, and the method is relatively simple. But pay attention to safety. The specific test method requirements are as follows. Hollow board production line www.handern com
① Take about 0.1g of sample and put it on clean glass or stainless steel plate; Heat it with a small fire on the gas lamp until it smokes, observe the color, smell of the smoke and whether the combustion speed is fast or slow, and use test paper (wet) to detect the acidity and basicity of the decomposed gas.
② Move the sample to the high-temperature area of the flame, observe the flammability of the sample and whether the combustion speed is fast or slow, and see the color of the flame
③ Move the sample away from the flame area to see whether the sample continues to burn or self extinguishes; Observe the disability. Remnant shape.
Plastic extrusion molding technician's manual, combustion characteristics of different plastics: flame retardant plastics include: polytetrafluoroethylene, polytetrafluoroethylene chloride, perfluoroethylene (ethylene propylene copolymer), perfluoroalkoxy polymer, polytetrafluoroethylene chloride ethylene copolymer, polyvinylidene fluoride, vinylidene fluoride hexafluoropropylene copolymer, tetrafluoroethylene hexafluoropropylene copolymer, polysulfone, polyethersulfone, aromatic polyamide, PVC, polyvinylidene chloride Chlorinated polyvinyl chloride, polyphenylene sulfide, melamine formaldehyde plastic. Plastics with poor flame retardancy include silicone plastics, polysulfone, polyphenylene ether and polycarbonate. Epoxy plastic, phenolic plastic, aliphatic polyamide, diallyl phthalate, pulse aldehyde plastic, chlorinated polyethylene, chlorosulfonated polyethylene. Flammable plastics include: polyethylene, polypropylene, polystyrene, polyformaldehyde, polyethylene terephthalate, polybutylene terephthalate, acrylic plastic, cellulose plastic, polyurethane, unsaturated polyester. Hollow board production line www.handern com
The solubility of plastic products and the dissolution of plastic products can be understood as the increase of the distance between molecular chains due to the interaction between solute molecules and solvent molecules. In addition to some linear polymers such as polytetrafluoroethylene, general plastics can be dissolved in some solvents. In the work, different plastic melting behaviors can be used to identify plastic varieties. Solubility of commonly used plastics: solubility of commonly used plastics plastic name: soluble insoluble polyethylene decahydronaphthalene, tetrahydronaphthalene, 1-chloronaphthalene (all 130 ℃ on alcohols, gasoline esters, CYCLOPROPYLENE ethanone), polystyrene butyl acetate, benzene, dimethylformamide, chloroform, diols, water, gasoline methyl chloride, methyl ethyl ketone, pyridine polyamic acid, phenol, trifluoroethanol, hexamethylphosphoramide alcohols, esters Hydrocarbon phenol, tetrachloroethane polyester benzyl alcohol, nitrohydrocarbon, phenol, hexamethylphosphoramide alcohol, ester, hydrocarbon polymethylstyrene benzene, toluene polyurethane dimethylformamide, tetrahydrofuran, formic acid, ethyl acetate, alcohol, gasoline, ester, hexamethylphosphoryl triamine benzene, water, hydrochloric acid cellulose acetate formic acid, glacial acetic acid, dichloromethane methanol
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