Plastics cannot replace metal materials, but many properties of plastics have surpassed alloys. And the application of plastic has exceeded the amount of steel, plastic can be said to be closely related to our lives. The plastic family can be rich and common six kinds of plastics, let's understand them.
1. PC material
PC has good transparency and general thermal stability. The disadvantage is that it does not feel good, especially after a period of use, the appearance looks "dirty", and it is also an engineering plastic, that is, plexiglass, such as polymethyl methacrylate. , polycarbonate, etc.
PC is a material that is widely used, such as mobile phone cases, laptops, etc., especially for the manufacture of milk bottles, space cups, and the like. Baby bottles have been controversial in recent years because they contain BPA. Residual bisphenol A in PC, the higher the temperature, the more released and the faster the speed. Therefore, PC water bottles should not be used to hold hot water.
2. PP material
PP plastic is isotactic crystallization and has good thermal stability, but the material is brittle and easy to break, mainly polypropylene material. The microwave lunch box is made of this material, which is resistant to high temperature of 130°C and has poor transparency. This is the only plastic box that can be put into the microwave oven and can be reused after careful cleaning.
It should be noted that, for some microwave lunch boxes, the box body is made of No. 05 PP, but the lid is made of No. 06 PS (polystyrene). The transparency of PS is average, but it is not resistant to high temperature, so it cannot be combined with the box body. Put in the microwave. To be on the safe side, remove the lid before placing the container in the microwave.
3. PVC material
PVC, also known as PVC, is polyvinyl chloride resin, which is often used to make engineering profiles and daily life plastic products, such as raincoats, building materials, plastic films, plastic boxes, etc. Excellent plasticity and low price. But it can only withstand high temperature of 81 ℃.
The toxic and harmful substances that plastic products of this material are prone to produce come from two aspects, one is the monomolecular vinyl chloride that is not fully polymerized during the production process, and the other is the harmful substances in the plasticizer. These two substances are easy to be precipitated when encountering high temperature and grease. After the toxic substances enter the human body with food, it is easy to cause cancer. At present, containers of this material have been rarely used for packaging food. Also, don't let it get hot.
4. PE material
PE is polyethylene. Cling film, plastic film, etc. are all of this material. The heat resistance is not strong. Usually, the qualified PE plastic wrap will have a hot melt phenomenon when the temperature exceeds 110 °C, leaving some plastic preparations that cannot be decomposed by the human body.
In addition, when the food is heated by wrapping the plastic wrap, the oil in the food can easily dissolve the harmful substances in the plastic wrap. Therefore, when the food is put into the microwave oven, the wrapped plastic wrap must be removed first.
5. PET material
PET, that is, polyethylene terephthalate, mineral water bottles and carbonated beverage bottles are all made of this material. Beverage bottles cannot be recycled to hold hot water. This material is heat-resistant to 70°C and is only suitable for warm or frozen drinks. It is easy to deform when filled with high-temperature liquid or heated, and there are substances that are harmful to the human body.
6. PMMA material
PMMA, that is, polymethyl methacrylate, also known as acrylic, acrylic or plexiglass, is called compressive force in Taiwan, and is often called agaric glue in Hong Kong. It has high transparency, low price, and easy machining. and other advantages, it is a commonly used glass replacement material. But its heat resistance is not high, non-toxic. It is widely used in the advertising logo production industry.
