There is a strange sign on the plastic package. It consists of three arrows-surrounded numbers ranging from 1 to 7. Numbers indicate the type of plastic used to make containers. Sometimes you can see the abbreviation of plastics under the label (for example, PET stands for Polyethylene Terephthalate). If you don't understand what they mean, it's of no use. Here's a quick guide to understanding them.
1. Polyethylene terephthalate (PET or PETE, Polyethylene Terephthalate)
It is unexpensive,light-weight and easy for recycling. This type of plastic is mainly used as a container for mouthwash, water, soft drinks and emollient oils. It can be recycled for other things, such as food and beverage containers, carpets, handbags and furniture.
2. HDPE，High Density Polyethylene
This is a widely-used recyclable plastic, HDPE can be used to make HDPE shampoo bottles
and detergent bottles, cereal boxes and shopping bags. It can be recycled into garbage cans, household cleaning containers, benches, pens and many other things.
3. PVC, Polyvinyl chloride
A rigid plastic that can be used in household HDPE shampoo bottles
and containers for detergents and cooking oils, as well as in windows, medical equipment and railings. It can be recovered, but because of the chlorine it contains, it will release toxic gases when burning, so the recycling process is difficult.
4. LDPE， Low Density Polyethylene
A soft, versatile plastic, LDPE is used to make extrudable bottles, toys, furniture and clothing. It can be recycled into airmail envelopes, furniture, floors and many other things.
Because of its high melting point, polypropylene can be used in heated containers for liquids and food, such as takeout boxes, but it can also be used to make medicine bottles, straws and syrup bottles. It can also be recycled for many things, including storage boxes, brushes, ice scrapers and trays.
6. PS, Polystyrene
When polystyrene is used to make foam products, it is called polystyrene foam (Styrofoam). It can be used as packing boxes for eggs, disposable dishes, furniture and electrical appliances. It is difficult to recycle, so many recycling stations refuse to accept it. If recycled, it can be reused to make electric switch boards, foam packaging and rulers.
All other types of plastic resins are represented by the number 7. It can be used in sunglasses, DVDS, water bottles and some food containers. Not all of them can be recycled, but if they can be recycled, they can be made into long plastic profiles and bottles.