In daily life, when we buy certain plastic products, we will generally find that it will be printed on the top of a triangle logo, and in the triangle logo will be marked inside the Arabic numerals 1-7. Some people may have a doubt, what is the meaning of this logo? In fact, this symbol is the plastic grade mark, the internal number is a few, it represents the plastic products are a few grades, and the grade number represents the different plastic raw materials made of plastic products. Here, let's take a look at each grade to understand exactly what raw materials represent it.
1: on behalf of PET, that is, polyethylene terephthalate, we live in the mineral water bottles are generally made of this raw material, the temperature range of this material is generally in -20 ℃ -65 ℃. So in the summer, try not to expose the mineral water to high temperatures, not to let may lead to plastic in part of the harmful substances precipitated into the water, causing harm to drinkers. Of course, it is not that no longer high temperature or low temperature environment is safe to use, there are scientific studies show that 1 type of plastic bottles used for too long will release carcinogens DEHP, so mineral water bottles such plastic products, after drinking throw into the garbage can on.
2, HDPE (high-density polyethylene), this material is very good resistance to acid and alkali, but only about 60 ℃ high temperature resistance. We use in our lives the packaging of toiletries and milk bottles are used to this plastic material. Like the above materials, this grade of plastic products are best not recycled.
3, PVC (polyvinyl chloride), because this material contains harmful substances in the plasticizer, so generally will not be used to package food, this plastic is generally used in raincoats, building materials, plastic mold, etc.
4, LDPE (low density polyethylene), we use in life PE cling film belongs to this grade, LDPE can withstand a maximum temperature of 110 ℃, so that if you want to put the food into the microwave oven heating, be sure to remove the cling film. At this high temperature, LDPE will not only hot melt into substances that the human body can not decompose, the harmful substances in it will also be precipitated by grease.
5, PP (polypropylene), heat-resistant up to 135 ℃, is the only kind of plastic products can be put into the microwave heating. Often used in the manufacture of microwave lunch boxes, soy milk boxes and other products.
6, PS (polystyrene), heat-resistant 70-90 degrees Celsius, but not acid and alkali resistance, and acid and alkali contact will decompose carcinogenic substances. We use the noodle bowl, foam instant food boxes, etc. is made of PS.
7, other classes (polycarbonate), some heat-resistant up to 120 degrees Celsius, but some poor quality PC material products will release harmful substances Bisphenol A, so this grade of plastic products or try not to use it for hot water.
Contact Person: Mrs. Ada