Yi sheng plastic cup, many friends have asked if the di […]
Yi sheng plastic cup, many friends have asked if the disposable plastic cup is harmful or toxic?
Many people feel plastic is the kind that can't be degraded. If you use it regularly, or you use it to drink hot things, it will produce something that is not good for the body. We know the plastic cup from the classification of the plastic cups that I shared before. Differences, and their respective uses.
The common disposable plastic cup is PP, and the chemical name is polypropylene.
Features: The density is small, the rigidity is hard, the hardness and heat resistance are all better than the low pressure polyethylene. It can be used at about 100 degrees.
Polypropylene is a non-toxic, odorless, odorless, milky, highly crystalline polymer with a density of 0.90--"0.91g/rm. It is one of the lightest species in all plastics. It is particularly stable to water, in water. The water absorption rate is only 0.O1%, and the molecular weight is about 80,000 to 150,000. The moldability is good, but the shrinkage rate is large (between 1% and 2.5%). The thick-walled products are easily sag, and for some parts with high dimensional accuracy, It is also difficult to meet the requirements, the surface gloss of the product is good, and it is easy to color.
Polypropylene has good heat resistance, and the product can be disinfected and sterilized at a temperature of 100° C. or higher, and is not deformed at 150° C. under the condition of no external force. The embrittlement temperature is -35°C, and embrittlement will occur below -35°C. Cold resistance is inferior to polyethylene. The report of the glass transition temperature of polypropylene is 18qC, OqC, 5°C, etc. This is also due to the fact that different samples are used. The ratio of the crystal phase to the amorphous phase is different, so that the amorphous chain length in the molecular chain is different. Caused. The melting temperature of polypropylene is about 40-50% higher than polyethylene, about 164-170°C, and 100% isotactic polypropylene.
At present, the US FDA believes that the release of styrene from polystyrene packaging material is unlikely to reach the harmful dose assessed by JECFA, so it is allowed to use it to package foods. The Canadian Health Department, after evaluation, concluded that the amount of styrene monomer that people are exposed to cannot be harmful to humans.
According to the current situation in the world and research evidence, there is no food safety problem for polystyrene food packaging materials as long as they are used properly.
In fact, the biggest source of human exposure to styrene monomer is air. Because, as a widely used industrial raw material, along with the development of modern industry, styrene already exists in the air, typically on the order of 1 ppb (1 ppb is equal to one part in one billion). To reduce its hazards, air pollution control is the key.
In addition, styrene naturally exists in some foods, such as strawberries, beef and peppers. In the production of wine and cheese, a certain amount of styrene is also produced. Studies have shown that the content of strawberry is 0.37-3.1ppb; the content of styrene in a bottle of beer can reach 10-200ppb; smoking also has styrene, smoking a cigarette usually has 20-48 micrograms of styrene. Although the hazard of this carcinogenicity cannot be simply compared, the amount of styrene monomer that a cup lid may dissolve is lower than the amount of styrene that is ingested when drinking a bottle of beer or smoking a cigarette.
For more at http://www.petcup.cc/ .