Plastics cannot replace metal materials, but many properties of plastics have surpassed alloys. And the application of plastics has exceeded the amount of steel, plastics can be said to be closely related to our lives. The plastic family can be rich and common six kinds of plastics, let's get to know 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". It also belongs to engineering plastics, namely organic glass, such as polymethyl methacrylate. , Polycarbonate, etc.

PC is a material that is widely used, such as mobile phone shells, notebook computers, etc., especially for the manufacture of baby bottles, space cups, etc. In recent years, milk bottles have been controversial because they contain bisphenol A. The residual bisphenol A in PC, the higher the temperature, the more release and the faster the speed. Therefore, the PC water bottle should not be used to hold hot water.

2. PP material

PP plastic is isotactic crystal, with good thermal stability, but the material is brittle and easy to break, mainly polypropylene material. The microwave lunch box is made of this material, resistant to high temperature of 130 ℃, and poor transparency. This is the only plastic box that can be placed in a microwave oven. It can be reused after careful cleaning.

It is important to note that some microwave lunch boxes, the box body is made of No. 05 PP, but the lid is made of No. 06 PS (polystyrene). PS has a normal transparency but is not resistant to high temperatures, so it cannot be combined with the box body. Put it in the microwave. To be safe, remove the lid of the container before putting it in the microwave.

3. PVC material

PVC, also known as PVC, is polyvinyl chloride resin. It is often made of engineering profiles and daily life plastic products, such as raincoats, building materials, plastic films, and plastic boxes. Good plasticity and low price. But it can only withstand high temperatures of 81°C.

The toxic and harmful substances that this kind of plastic products are easy 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 separate out when encountering high temperature and grease. After the toxic substances enter the human body with food, they are easy to cause cancer. At present, containers of this material have been less used for packaging food. Also, don't let it get hot.

4. PE material

PE means polyethylene. Cling film, plastic film, etc. are all of this material. The heat resistance is not strong, and usually qualified PE cling film will melt when the temperature exceeds 110 ℃, leaving some plastic preparations that cannot be decomposed by the human body.

In addition, when food is wrapped with plastic wrap and heated, the fat in the food can easily dissolve 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, namely 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 up to 70°C. It is only suitable for warm or frozen drinks. It is easy to deform when it is filled with high-temperature liquid or heated, and harmful substances to the human body may be dissolved.

6. PMMA material

PMMA, also known as polymethyl methacrylate, is also known as acrylic, acrylic or plexiglass. It is called pressurized in Taiwan, and is often called agaric in Hong Kong. It has high transparency, low price, and easy mechanical processing. And other advantages, it is often used as a substitute for glass. But its heat resistance is not high and it is non-toxic. Large-scale application in the advertising logo production industry.