Have you noticed a triangle on the bottom of the plastic container? What do the different numbers in the triangle represent? LGLPAK.LTD will take you to understand what the numbers represent.
There are 1-7 numbers in the triangle at the bottom of the plastic container, which represent different plastic materials, and these plastic material codes are an important basis for its safety.
1-PET PET bottle
It is made of polyethylene terephthalate, which is non-toxic, has good air tightness, and does not produce flocs. After regeneration, it becomes a secondary material with economic benefits, because its use is becoming more and more extensive. , Secondary materials are supplied at home and abroad, and also exported to mainland China, which can be used as non-woven fibers, zippers, filling materials, etc.
2-HDPE high density polyethylene
White powder or granular product, non-toxic and tasteless, crystallinity is 80%～90%, softening point is 125～l 35℃, service temperature can reach 100℃, strength is twice that of low density polyethylene, plastic bag Common materials.
3-PVC polyvinyl chloride
It is currently the second largest plastic product in the world after polyethylene. It has an amorphous structure of white powder, with a small degree of branching, a relative density of about 1.4, a glass transition temperature of 77~90°C, and a decomposition at about 170°C. It has poor thermal stability and decomposes to produce hydrogen chloride at temperatures above 100°C or long-term sunlight exposure.
4-LDPE low density polyethylene
It is the most used variety in the plastic packaging and printing industry in various countries. It is processed into a tubular film by the blow molding method and is suitable for food packaging, daily chemical packaging, fiber product packaging, etc. The material is not resistant to heat and will melt when the temperature exceeds 110°C. If the food is wrapped in plastic wrap and heated, it will dissolve harmful substances.
5-PP polypropylene
Its mechanical strength, folding strength, air density, and moisture barrier are better than ordinary plastic film. Because this plastic film has excellent transparency, the reproduced color after printing is extremely bright and beautiful, and it is an important material for plastic composite flexible packaging. It is resistant to corrosion by acids, alkalis, salt solutions and a variety of organic solvents below 80℃, and can decompose under high temperature and oxidation.
6-PS polystyrene
The material used to make evening instant noodle boxes and fast food boxes has good heat resistance, but cannot be placed in a microwave oven. High temperature will release toxic chemicals. Strong acids and alkalis can also decompose polystyrene which is harmful to the human body. Be careful when using it.
7-PC polycarbonate and others
PC is a widely used material, mostly used in the manufacture of baby bottles, space cups, etc. It is controversial because of the presence of bisphenol A. The higher the temperature, the more the release, and the faster the speed. Therefore, do not use a PC bottle to hold hot water and do not expose it to direct sunlight.
I think everyone already understands the meaning of numbers. You can pay more attention to it in your life and try to avoid substances that are harmful to your body. LGLPAK.LTD will take you to understand the plastic industry from a professional perspective.
Post time: Sep-23-2020