Distinguishing plastic methods
LDPE (Chinese name: Low Density High Pressure Polyethylene):
Sensory identification: Soft to the touch: White and transparent, but with average transparency, often with adhesive tape and printed words. (Note: Tape and printed words are inevitable, but their content must be controlled as these will affect prices in the market)
Combustion identification: The combustion flame is yellow above and blue below; When burning, there is no smoke, a smell of paraffin, melting and dripping, and easy to wire.
　
EVA (Chinese name: ethylene vinyl acetate copolymer):
Sensory identification: The surface is soft; Stretching toughness is stronger than LDPE, with a sticky feel (but no adhesive on the surface); White and transparent, with high transparency. The appearance and feel are very similar to those of PVC film, and attention should be paid to distinguishing them.
Combustion identification: When burning, it has the same odor of paraffin as LDPE, with a slightly sour taste; The burning flame is yellow above and blue below; There is no smoke when burning. Melt dripping, easy to wire.
Note: This product is one of the PE types and has the same price as LDPE. It can be used for regeneration granulation and has the same quality requirements as PE.
　
PP (Polypropylene):
Sensory identification: This product is white and transparent, with higher transparency compared to LDPE, and there is a sound when kneaded.
Combustion identification: During combustion, the flame is yellow and blue in color, with a smell similar to petroleum, molten droplets, and no black smoke during combustion.
　
PET film (polyurethane)
Sensory identification: This product is white and transparent, with a hard feel and a sound when rubbed. The appearance looks like PP.
Combustion identification: There is black smoke during combustion, and there is a phenomenon of flame jumping. After combustion, the surface of the material is black carbonized, and the black carbonized substance after burning is rubbed with fingers. The carbide is in powder form.
　
PVC film (polyvinyl chloride)
Sensory identification: The appearance is very similar to EVA but has elasticity.
Combustion identification: Black smoke is emitted during combustion, which extinguishes immediately after leaving the fire. The combustion surface is black and there is no melting or dripping phenomenon.
　
Nylon Copolymer (LDPE+Nylon):
Sensory identification: This product has a very similar sensory appearance to LDPE.
Combustion identification: The combustion flame is yellow on the top and blue on the bottom, smokeless during combustion, with a smell of paraffin, melting and dripping, easy to wire, but different from LDPE, there is a smell of hair burning during natural combustion, and it turns light yellow after combustion.
Attention: Nylon copolymers cannot be used for regenerative granulation, and should be strictly distinguished from LDPE and the content in large parts should be strictly controlled.
　
PE+PP copolymer
Sensory identification: Compared with LDPE, the transparency of this product is much higher, and there is no difference in feel between LDPE and LDPE. The tear test is very similar to PP film, making it transparent and pure white.
Combustion identification: The flame of this product is all yellow during combustion, with molten droplets, no black smoke, and an odor similar to petroleum.
　
PP+PET copolymer
Sensory identification: The appearance is similar to PP, with extremely high transparency, and the sound when rubbing is greater than that of PP.
Combustion identification: There is black smoke during combustion, there is a phenomenon of flame jumping, and the combustion surface shows black carbonization.
　
PE+PET composite film
Sensory identification: The surface of the material is smooth on one side and not smooth on the other, white and transparent.
Combustion identification: When burning, it looks like PET, without melting and dripping phenomenon, with black carbonization on the combustion surface, black smoke, and jumping fire phenomenon, with a paraffin smell of PE.