1. ** Chemical Structure ** :
- **PETG** : is an amorphous copolyester formed on the basis of PET, with 1, 4-cyclohexanedimethanol (CHDM) partially replacing ethylene glycol. This change in chemical structure makes the performance of PETG different from that of PET.
- **PET** : linear homopolyPET formed by condensation of terephthalic acid and ethylene glycol.
2. ** Physical properties ** :
- ** Transparency ** :
- **PETG** : With higher transparency, its transparency is comparable to acrylic, and even higher than acrylic in some cases, able to present a very clear visual effect.
- **PET** : Although it also has a good transparency, but in comparison, the transparency is slightly lower than PETG.
- ** Flexibility ** :
- **PETG** : Better flexibility, relatively soft, has good bending properties, is not easy to break or break during processing and use, and can adapt to complex shapes and structural needs.
- **PET** : The texture is relatively hard, relatively brittle, poor flexibility, easy to break when affected by external force or bending.
- ** Temperature resistance ** :
- **PETG** : has good temperature resistance, can maintain stable performance in a wide temperature range, usually can be used in the temperature range of -80 ° C to 65 ° C.
- **PET** : relatively poor temperature resistance, easy to deform at high temperatures, generally used in the temperature range of -20 ° C to about 70 ° C.
3. ** Processing performance ** :
- ** Molding difficulty ** :
- **PETG** : Excellent processing and molding performance, easy to process, can be designed according to the designer's intention of any shape, can use traditional extrusion, injection molding, blow molding and blister molding methods, and short molding cycle, low temperature, higher yield.
- **PET** : The processing difficulty is relatively high, the molding process requires higher temperature and pressure, and the requirements for the mold are relatively high.
- ** Drying requirements ** :
- **PETG** : It needs to be dried before processing, but the drying requirements are relatively low, generally drying at 120-160℉ for about 4-6 hours.
- **PET** : The requirements for drying conditions are more strict, and it needs to be dried in a low humidity environment, otherwise it is easy to affect the quality of the product.
4. ** Application Field ** :
- **PETG** : Often used in cosmetic bottles, perfume bottles, pharmaceutical packaging containers and other packaging fields with high transparency and safety requirements, it can also be used in plate, sheet, high-performance shrink film, profile and other markets, as well as some areas requiring high impact resistance and chemical resistance, such as auto parts, medical equipment and so on.
- **PET** : mainly used in the packaging of all kinds of beverage containers, such as mineral water bottles, carbonated beverage bottles, etc., but also used in the packaging of food, medicine, and textile fibers, electrical insulation, film and other fields.
