What is the difference between PET and PETG?

PETG is a modified PET plastic. It is a transparent plastic, a non-crystalline copolyester, PETG commonly used comonomer is 1,4-cyclohexanedimethanol (CHDM), the full name is polyethylene terephthalate-1,4-cyclohexanedimethanol. Compared with PET, there are more 1,4-cyclohexanedimethanol comonomers, and compared with PCT, there are more ethylene glycol comonomers. Therefore, the performance of PETG is quite different from that of PET and PCT. Its products are highly transparent and have excellent impact resistance, especially suitable for forming thick-walled transparent products.

As a packaging material, PETG has the following advantages:
1. Higher transparency, light transmittance up to 90%, can reach the transparency of plexiglass;
2. It has stronger rigidity and hardness, excellent scratch resistance, impact resistance and toughness;
3. In terms of chemical resistance, oil resistance, weather resistance (yellowing) performance, mechanical strength, and barrier performance to oxygen and water vapor, PETG is also better than PET;
4. Non-toxic, reliable hygienic performance, can be used for food, medicine and other packaging, and can be sterilized by gamma rays;
5. It meets the requirements of environmental protection and can be recycled economically and conveniently. When the waste is incinerated, no harmful substances that endanger the environment will be produced.

As a packaging material, PET has the following advantages:
1. It has good mechanical properties, the impact strength is 3~5 times that of other films, good folding resistance, and still has good toughness at -30°C;
2. Resistant to oil, fat, dilute acid, dilute alkali, and most solvents;
3. Low gas and water vapor permeability, excellent gas, water, oil and odor resistance;
4. Non-toxic, tasteless, hygienic and safe, can be directly used in food packaging;
5. The price of raw materials is cheaper than PETG, and the finished product is light in weight and resistant to breaking, which is convenient for manufacturers to reduce production and transportation costs, and the overall cost performance is high.

PETG is superior to ordinary PET in surface properties such as printability and adhesion. PETG transparency is comparable to PMMA. The hardness, smoothness, and post-processing capabilities of the PETG are stronger than PET. Compared with PET, the disadvantage of PCTG is also obvious, that is, the price is very high, which is 2~3 times that of PET. At present, most of the packaging bottle materials on the market are mainly PET materials. PET materials have the characteristics of light weight, high transparency, impact resistance and not fragile.

Summary: PETG is an upgraded version of PET, with higher transparency, higher toughness, better impact resistance, and of course a higher price.