One of the food blister trays:

1, PP material can be placed in the microwave oven, but mainly to open the lid;

2. Polypropylene (PP) has good heat resistance, and the product can be sterilized and sterilized at a temperature above 100 ° C. Under the condition of no external force, it is not deformed at 150 ° C. The embrittlement temperature is -35 ° C, embrittlement occurs below -35 ° C, and the cold resistance is not as good as polyethylene. The reported values for the glass transition temperature of polypropylene are 18qC, OqC, 5°C, etc., which is also because people use different samples, in which the ratio of crystal phase to amorphous phase is different, so that the chain length of the amorphous part in the molecular chain is different. Caused. The melting temperature of polypropylene is about 40-50% higher than that of polyethylene, about 164-170 ° C, and the melting point of 100% isotactic polypropylene is 176 ° C.

3, material identification: you can see the number inside the triangle of the box or the bottom of the bottle: No. 1 PET: heat resistant to 65 ° C, cold to -20 ° C. HDPE No. 2: It is not recommended to recycle. PVC No. 3: It is best not to buy. No. 4 LDPE: heat resistance is not strong. No. 5 PP: microwave lunch box, crisper, high temperature resistant 120 °C. PS No. 6: It is heat-resistant and cold-resistant, but it cannot be placed in a microwave oven. Other PCs No. 7: kettles, cups, bottles.