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How to choose a plastic container? They have "identity cards"
Today, there are many plastic containers on the market, plastic cups, plastic lunch boxes, plastic bottles and so on. These plastic containers are all things we frequently touch every day. How do we choose them? In fact, these plastic containers are code-named, and they also have "identity cards". Different codes represent different uses, so don't ignore them!
What kinds of plastic containers are there?
Each plastic container has an "identity card", usually at the bottom of the plastic container. This is the recycling mark for plastic products, which is formulated by the relevant agencies of the US plastics industry. This set of markings will be marked on the container or package, from No. 1 to No. 7, each number representing a plastic container. When buying plastic containers, consumers can identify them through the triangle recycling mark. The following are the codes for commonly used plastic products:
1 represents polyethylene terephthalate
The container made of this material is a common plastic bottle filled with soda water, also known as "Boute bottle", which is heat-resistant to 70 ° C, easily deformed, and has harmful substances to the human body. This plastic container should not be placed in the car to basking in the sun, nor should it contain alcohol, oil, etc.
2 represents high density polyethylene
Containers containing detergents, shampoos, shower gels, cooking oils, pesticides, etc. are mostly made of HDPE. Most of the containers are opaque and feel like wax. It is not recommended to use such a container as a water cup, or to store other items in the storage container, and not to recycle.
3 represents polyvinyl chloride
It is mostly used to manufacture water pipes, raincoats, school bags, building materials, plastic films, plastic boxes and other utensils. PVC is excellent in plasticity and low in price, so it is very common to use, but it is easy to cause harmful substances to precipitate at high temperatures, and is rarely used for food packaging. These containers are difficult to clean and residue, and should not be recycled.
4 represents low density polyethylene
It is suitable for various molding processes of thermoplastic molding processing and has good molding processability. LDPE is mainly used as a film product, and is also used in injection molding products, medical appliances, pharmaceutical and food packaging materials, blow molding hollow molded products, and the like. However, the plastic wrap made of LDPE does not enter the microwave oven.
5 represents polypropylene
It is used in the manufacture of food containers for buckets, trash cans, baskets, baskets and microwave ovens. With a melting point of up to 167 ° C, PP is the only plastic box that can be placed in a microwave oven and can be reused after careful cleaning. It should be noted that some microwave lunch boxes are made of No. 5 PP, but the cover is made of other plastics. Since most other plastics cannot withstand high temperatures, they cannot be placed in the microwave oven together with the case.
6 stands for polystyrene
Due to the low water absorption of PS, it is mostly used in the manufacture of building materials, toys, stationery, rollers, as well as cup boxes or disposable tableware for instant drinks, such as common bowl noodles boxes and fast food boxes. PS containers should not be placed in the microwave to prevent release of chemicals due to excessive temperatures. When the PS container is filled with acid or alkaline substances, it will decompose carcinogens. Avoid using hot food boxes to pack hot food, and don't use microwave ovens to cook instant noodles.
7 represents other classes
Mainly polycarbonate (PC), commonly found in kettles, space cups, and bottles.
How to choose?
When buying a lunch box, the number in the triangle below is preferably one of 5, 6, and 7, because of the higher security. If the lunch box is to be exothermic and long-term use, it is generally good plastics such as 5 or 7. If the lunch box used is a cool food or a food at room temperature, you can use a lower-priced lunch box, basically do not need to see what material. However, if you need to discharge such a liquid, you need to use one of 5, 6, and 7 at room temperature. For example, plastic No. 1 will release harmful substances in bottles over one year at normal temperature. If the lunch box is to be heated in a microwave oven, you need to buy PP plastic, which is No. 5.
Be optimistic about the plastic lunch box with or without damage or scratches. In order to be durable, a general lunch box will add some ingredients to improve the physical properties of the lunch box. Do not buy if there is damage, there are a lot of deep scratches or scratches.