PET is a milky white or light yellow, highly crystalline polymer with a smooth and shiny surface. It has excellent physical and mechanical properties in a wide temperature range. The long-term use temperature can reach 120℃. The electrical insulation is excellent. Even at high temperature and high frequency, its electrical performance is still good, but the corona resistance is poor. Creep resistance, fatigue resistance, friction resistance and dimensional stability are all very good.
Advantages of PET as a packaging material:
①It has good mechanical properties, impact strength is 3~5 times that of other films, and good folding resistance.
②It is resistant to oil, fat, dilute acid, dilute alkali, and most solvents.
③It has excellent resistance to high and low temperatures. It can be used for a long time within a temperature range of 120°C, and can withstand high temperatures of 150°C and low temperatures of -70°C in short-term use, and has little effect on its mechanical properties at high and low temperatures.
④The gas and water vapor permeability is low, and it has excellent gas, water, oil and odor resistance.
⑤High transparency, can block ultraviolet rays and good gloss.
⑥Non-toxic, tasteless, good hygiene and safety, and can be directly used for food packaging.
The bottom of the plastic bottle has a triangle with an arrow, and there is a number inside the triangle. The numbers in the triangle at the bottom of the plastic bottle refer to the ingredients contained in the bottle and the impact of the ingredients on human health ——
1-PET polyethylene terephthalate
Commonly found in mineral water bottles, carbonated beverage bottles, etc. When the temperature reaches 70℃, it is easy to deform, and some harmful substances are melted. No. 1 plastic product may release carcinogen DEHP after 10 months of use. This kind of bottle can not be placed in the car to bask in the sun, and can not contain alcohol, oil and other substances.
2-HDPE high density polyethylene
Commonly found in white medicine bottles, cleaning supplies, and bath products. Do not use it as a water cup or as a storage container for other items.
3-PVC polyvinyl chloride
Commonly found in raincoats, building materials, plastic films, plastic boxes, etc. It has excellent plasticity and low price, so it is widely used. It reaches its peak when heat resistance reaches 81℃. It is easy to produce harmful substances at high temperature and is rarely used in food packaging. Difficult to clean, easy to remain, do not recycle.
Common in cling film, plastic film, etc. Hazardous substances are produced at high temperatures. After the toxic substances enter the human body with food, they may cause diseases such as breast cancer and birth defects of newborns.
It is commonly found in soy milk bottles, yogurt bottles, and microwave lunch boxes. It has a melting point of up to 167°C. It is the only plastic product that can be placed in a microwave oven and can be reused after careful cleaning. It should be noted that some microwave lunch boxes, the box body is made of No. 5 PP, but the lid is made of No. 1 PET. Since PET cannot withstand high temperatures, it cannot be placed in the microwave together with the box.
Commonly found in bowls of instant noodle boxes and fast food boxes. Do not put it in a microwave oven to avoid the release of harmful chemicals due to high temperature. Avoid using fast food boxes to pack hot food, and don’t cook instant noodles in a microwave oven.
7-PC other categories
Commonly found in water bottles, space cups, and baby bottles. Department stores often use these materials as gifts. However, the water cup of this material easily releases the toxic substance bisphenol A, which is harmful to the human body. In addition, do not heat or expose to the sun when using this type of water cup.