How to Distinguish Various Types of Plastics?

Sep 17, 2022

Distinguishing plastic products by burning and smells

Items	Burning conditions	Burning flame	Being away from the fire	Smells
PP	It is easy to melt and drip.	Yellow on top and blue on bottom	Less smoke and keep burning	Having a smell of petroleum
PE	It is easy to melt and drip.	Yellow on top and blue on bottom	Keep burning	Having a smell of paraffin burning smell
PVC	PVC is difficult to soften.	Yellow on top and green on the bottom	There is smoke, and no smoke when it is away from fire.	Being pungent sour
POM	It is easy to melt and drip.	Yellow on the top and blue on the bottom	It is smokeless, and continues to burn.	It has a strong smell of formaldehyde.
PS	It is easy to soften and foam.	It is orange.	There is thick black smoke and charcoal continues; the surface is oily and bright.	Special vinyl odor
PA	Slow melting and dripping	Blistering	Slowly extinguishing	Having special wool, nail odor
PMMA	PMMA is easy to melt and foam.	It is light blue and white.	It is smokeless and continues to burn.	It has a strong sour smell of flowers and fruits, rotten vegetables.
PC	It is easy to burn.	It is easy to soften and foam.	There is a small amount of black smoke and is extinguished after it is away from the fire.	There is no special smell.
PTFE	It does not burn.	-	-	It decomposes in a fire with a pungent hydrogen fluoride odor.
PET	It is easy to soften and foam.	Orange	There is a small amount of black smoke and it slowly extinguishes when being away from the fire	The smell of going sour
ABS	It softens and burns slowly, and has no dripping.	Yellow	Black smoke, keep burning	Special smells

Distinguishing plastic products by uses
According to the use, there are some similarities between PP and PE, ABS and PS.
Common products made from PE: handbags, water pipes, oil drums, beverage bottles (calcium milk bottles) and daily necessities. High pressure and linear are often used in films such as industrial films, agricultural films, etc. Low pressure can be used for packaging, injection molding, hollow and so on.

Common plastic products made from PP are basins, barrels, furniture, films, woven bags, bottle caps, car bumpers, and non-woven fabrics.

Common products made from PS are stationery, cups, toys, food containers, home appliance shells, foam packaging materials, electrical accessories, etc. The main use is injection molding, foaming, foaming and so on.

Common products made from PVC are sheets, pipes, shoe soles, toys, doors and windows, wire sheaths, stationery, medical supplies, etc. PVC is often used for motorcycle accessories, and there are many injected PVC products.

Common products made from PET are bottle products such as cola and mineral water bottles, and it is mainly used for chemical fiber and injection molding.

Distinguishing plastic products by appearance and hand feeling
According to the appearance and hand feeling, you can know what the product is made from, so appearance is also very important.

PE: It is soft, white and transparent, but the transparency is average, often with tape and printed words. Please note that tape and printed words are unavoidable, but their content must be controlled, because these will affect the price in the market. When PE is uncolored, it is milky white, translucent, and waxy. It is smooth and soft, soft but tough. It can be slightly elongated. Generally, low-density polyethylene is softer and has better transparency; high-density polyethylene is harder.

PP: This product is white and transparent. Compared with LDPE, the transparency is better, and there is a sound when you rub PP. It is white, translucent and waxy when unpigmented; and it is lighter than polyethylene. The transparency of PP is also better than that of polyethylene, and it is harder than polyethylene.

PVC: Its natural color is yellowish and it is translucent and shiny. The transparency of PVC is better than that of polyethylene and PP, but worse than that of polystyrene. Depending on the number of additives, it can be divided into soft and hard polyvinyl chloride. There are soft products which are soft and tough, and sticky. There are also hard products with hardness higher than that of low-density polyethylene and lower than polypropylene. Whitening occurs at the inflection part.

PS: It is transparent when unpigmented. When the product is dropped or knocked, it has a metal-like crisp sound, good luster and transparency, is similar to glass, brittle and easy to break, and fingernail marks will leave on the surface of the product after scratching. Modified PS is opaque.

PET: It has good transparency, and its strength and toughness are better than that of polystyrene and polyvinyl chloride; it is not easy to break. It is white, transparent and hard, and there is a sound when it is rubbed. It looks like PP.