1. High-density polyethylene (HDPE), suitable for bottl […]
1. High-density polyethylene (HDPE), suitable for bottles of food and medicine, cleaning supplies and bath products, shopping bags, trash cans.
2. Polyvinyl chloride (PVC) is made by the polymerization of vinyl chloride. Polyvinyl chloride plastics at high temperature and in contact with grease easily release phthalates and incompletely polymerized toxic vinyl chloride monomers. The cling film made of polyvinyl chloride has good transparency, is not easy to break, has strong adhesion, and is low in price. The film that we see in supermarkets and hypermarkets is the film that sticks very firmly on the box. According to its characteristics, it is only suitable for the refrigeration and preservation of vegetables and fruits. It is not suitable for meat, cakes and other foods containing more fat, and it is not suitable for microwave heating.
3. Low-density polyethylene (LDPE) plastic film and cling film have good water barrier properties, so paper-made milk cartons, beverage boxes and other packaging boxes use it as the inner film. Because the low-density polyethylene cling film will melt when it exceeds 120℃, if you use the cling film to wrap the food and heat it, the oil in the food will melt some of the ingredients in the cling film. Therefore, you need to keep it fresh before entering the microwave. When the film is removed, at least the food should not be in direct contact with the plastic wrap. Low-density polyethylene itself does not have degradability, and the current "plastic limit order" mainly restricts it.
4. Polypropylene (PP), polymerized by propylene, is more transparent than polyethylene and harder than polyethylene. Most of the packaging boxes in restaurants are made of it. The plastic boxes made can be heated in a microwave oven.
5. Polystyrene (PS), polymerized from styrene, is often used as a bowl of instant noodle boxes and fast food boxes. It is heat-resistant and cold-resistant, but if the temperature is too high, it will release harmful substances, so do not put the bowl of instant noodles in the microwave to heat, and try not to use it to hold hot food, and also not contain strong acid (if juice) and Strong alkaline substance, otherwise it will release styrene and auxiliary materials.
6. Polycarbonate (PC), which is synthesized using bisphenol A and diphenyl carbonate as raw materials, has excellent impact toughness, mechanical strength, and transparency, so it is known as "transparent metal". Commonly used in the manufacture of water bottles, water cups, milk bottles, etc. In the process of making PC, the raw material bisphenol A should completely become a structural component of the plastic and should not be released during use, but in fact it is often not possible. There will be a small part of bisphenol A that cannot be completely converted into the plastic. Is released into food. Bisphenol A is an endocrine disruptor and is particularly harmful to developing fetuses and children. It may cause miscarriage, congenital mental retardation, and mental retardation of infants and young children. Some studies have also confirmed that bisphenol A can interfere with and antagonize thyroxine and inhibit the secretion of testosterone, affect the sexual development of boys, hinder the formation of sperm, which may affect fertility. Therefore, extra care should be taken in use, including polycarbonate bottles, so as not to harm the baby's sexual development.