The bottom of the plastic product

Update:21 Jul 2017
Summary:

Plastic in our lives can be seen everywhere, plastic pr […]

Plastic in our lives can be seen everywhere, plastic products are made of different materials, different materials, the application is also different. The bottom of the plastic bottle represents the different materials.
The numeral "1" represents polyethylene terephthalate, i.e., PET. Mainly used for mineral water bottles, carbonated, fruit juice bottles and soy sauce vinegar bottles. PET bottle heat temperature of 70 degrees Celsius, only suitable for heating or cold drink, filled with water or heating is easy to deformation, harmful substances on the human body will be dissolved.
The numeral "2" represents high density polyethylene, or HDPE. HDPE and other plastic composite film, also used for aquatic products.
The number "3" represents polyvinyl chloride, ie PVC, which is also used to make intravenous infusion bags and disposable sterile infusion devices because of the low price. However, long-term use can lead to the accumulation of hazardous substances DEHP. Therefore, from a security point of view, the pharmaceutical industry to choose non-PVC materials is the future trend.
The number "4" is low density polyethylene, ie LDPE. 4 plastic for a large number of packaging. LDPE is mainly used for the production of plastic wrap and food containing plastic bags.
The number "5" is polypropylene, ie PP. One is the container. PP is the only plastic container that can be placed in a microwave oven and is a plastic container that can be used repeatedly to store food, oil and condiments as a storage container. Two do packaging film, there are unstretched and two-way stretch. Unpended Polypropylene (CPP) is commonly used in snacks, bread, fruit and other packaging; biaxially stretched polypropylene (BOPP) is comparable with cellophane flexible packaging materials.
The number "6" is polystyrene, ie PS. PS is mainly processed into thin film and foam on the packaging. Film for fruit and vegetable packaging; foam for bowl and instant noodles and fast food boxes, but not high temperature, it can not be placed in a microwave oven directly heated, so as to avoid the high temperature and release toxic chemicals.
The number "7" is polycarbonate, or PC or other plastic. PC material made of plastic containers, may release toxic bisphenol A, the higher the temperature release the more, the faster the speed, so do not use the heat, do not direct sunlight in the sun.