What are the differences among PET, PE and PVC?

Although there are many materials for plastic bottles, the functions and characteristics of plastic bottles are different according to different materials, so please try to compare plastic bottles with plastic bottles.

Characteristics: PE is soft and has a waxy texture when touched. Compared with the same plastic, it is relatively light in weight and has a certain degree of transparency. The flame when burning is blue.

Toxic: non toxic, harmless to human body.

High density polyethylene (hare) sold on the market has a density of 0.945 ~ 0.9g/cm3 and a melting point of 125 ~ 137 ℃.

Linear low density PE (llare), density 0.925g/cm3, melting point 120 ~ 125 ℃.

High pressure low density PE (HP - L magnetic), density 0.918 g / cm3, melting point 105 ~ 115 ℃.

Application of polypropylene (PP): tableware, pots, plastic barrels, thermos bottles, woven bags, etc. of microwave ovens.

Characteristics: high chemical stability, good sanitary performance and high heat resistance. The tableware of the electronic microwave oven is made of plastic products.

Toxic: non toxic, harmless to human body.

The polymer can have three stereoscopic structures: isoregular, regular and irregular polyalkels, and the first two kinds of crystals, while the latter cannot. The basic market structure of polypropylene products sold on the market is that the melting point is 164 ~ 170 degrees, the density of crystalline part is 0.935g/cm3, and the non clean part is 0.851g/cm3.

The biggest disadvantage of PP is that it is easy to age. Now, it is overcome by antioxidant and absorbent of Viola.

Polyester (PET) applications: plastic bottles, medicine bottles, cosmetic bottles, oil bottles, as well as various bottle caps and heat preservation caps.

Characteristics: good transparency, not easy to damage, good chemical stability, suitable for the packaging of a variety of liquid or solid drugs. It has good shielding against ultraviolet rays.

Toxic: non toxic.

PET plastic bottle is the mainstream of beverage packaging. PET plastic bottles play a leading role in China's beverage packaging industry. So far, no better than PET plastic bottles have been found. PP bottles are mainly formed in the forming machine by focusing on the one-step process and heating the two-step process. The formed PP bottles are bright, strong and heat-resistant, and the price is lower than the radical data. Possible 100 ℃

In the feeding bottle, the high-precision PP plastic bottle can be produced by the methods of 0.1% - 0.4% sandieklein shrinking nuclear agent, spraying, blowing and injection. PP plastic bottles can withstand temperature, and the sensitivity of bottle type is very good. They are inferior in terms of safety, hygiene and food sense persistence of content, and the price is cheaper than pet, PS, PE and other materials. PP plastic bottles, the scale of use in the beverage packaging market has been close to PET bottles, and the skills of resin, antireflection agent and mechanical equipment have been continuously developed. PP containers can replace glass, pet and PVC containers, with broad market prospects.

Precautions for storing reagents in wide mouth bottles and fine mouth bottles

As the name suggests, a narrow mouth bottle is a reagent bottle with a small mouth. Because the mouth is small, it is generally used to contain liquid reagents, including brown and transparent. The brown bottle is used to contain light sensitive reagents, reducing the probability of reagent decomposition in the presence of light. There should be some things to pay attention to when using. The fine mouth bottle is a vessel that cannot be heated. When taking and placing reagents, put the cork upside down on the table. After use, tighten the cork. If necessary, seal it for storage. Because the fine mouth bottle has a frosted mouth and a frosted glass bottle cap, it cannot store alkaline reagents. When storing alkaline reagents, use a rubber plug.

The wide mouth bottle is of course a reagent bottle with a wide mouth. Because the mouth is wide, it is convenient for medicine spoons and other objects to take solid reagents. Therefore, the wide mouth bottle is generally suitable for containing solids and powders. There are two kinds of transparent and brown bottles, of which Brown is used for containing articles that are easy to decompose when exposed to light. Just like the fine mouth bottle, when taking the reagent, put the cork upside down on the table and tighten the cork after use. Due to the frosted mouth and frosted glass bottle cap, the alkaline reagent cannot be stored. Use a rubber stopper when storing alkaline items.

There are many factors that affect the quality of plastic bottles. To sum up, they mainly include the following aspects:

1. if we want to produce plastic products, we need plastic molds first. Therefore, plastic molds are the basis of plastic product production. Therefore, the quality of plastic molds is directly related to the quality of plastic parts. The precision requirements of plastic mold, mold structure, mold surface treatment, etc. will be reflected on the plastic parts. So for customers, to find a suitable plastic mold factory is the first.

2. plastic molds need to be put into the injection molding machine to produce plastic parts, so the requirements for the injection molding machine will also affect the quality of plastic parts. For example, the size of the injection molding machine, the injection parameters of the injection molding machine, etc

3. after all, plastic products are produced by people, so human factors are also very important. The quality of plastic parts produced by skilled and experienced adjustment workers is often better than that of inexperienced novices.

From the above analysis, qualified plastic parts need mold quality. Injection molding machines and production workers are closely related.