PETG is a transparent, amorphous copolyester. Compared with PET, there is more 1,4-cyclohexanedimethanol comonomer. More ethylene glycol comonomer than PCT. Therefore, the performance of PETG is very different from that of PET and PCT.
PETG sheet has outstanding toughness and high impact strength, and its impact strength is 3 to 10 times that of modified polyacrylates. It has a wide processing range, high mechanical strength and excellent flexibility.
PETG has glass-like transparency and close to glass density, is easy to process, and can be injection, injection stretch blow and extrusion blow molding. It can also produce unique shapes, appearances and special effects. It is also possible to use other polyesters, elastomers or ABS for overmolding. The order of temperature resistance with other materials is: PC>PP>PMMA>ABS>HIPS>PETG>PVC>PE.
Scope of application of PETG
1. Plate and sheet: Because of its outstanding toughness, high impact strength and excellent formability, cold bending without whitening and cracks, easy to print and decorate, it is widely used in indoor signs, storage racks, automatic sales cargo plane etc.
PETG cards and credit cards are currently mainly used in Europe, and have also been used more and more in North America and Asia. For countries that require more environmentally friendly card materials, PETG may be an alternative to PVC materials. For example, the second-generation ID card is made of PETG film.
2. Pipe material: Due to the good toughness of PETG, the product is hard, transparent, and glossy, and does not turn white under pressure, and is easy to form and post-processing. Widely used in architectural decoration and materials.
3. For film: PETG can be specially used in high-performance shrink film, with a final shrinkage rate of more than 70%, which can be made into the packaging of complex shape containers, with high absorbing power, high transparency and high gloss. The advantages of low natural shrinkage rate during storage are used in shrink labels for beverage bottles, food, gift packaging and electronic products.
4. Bottle use: PETG has passed the US FDA's food contact standards. It can be used to improve the low toughness of traditional polyester beverage bottles. It is highly transparent and not easy to break. It can block light, isolate air, ensure the quality of beverages, and has an explosion-proof function to prevent debris from splashing when the bottle is broken. It is especially suitable for the manufacture of large-capacity thick-walled transparent containers, such as beer bottles.
PETG compared to PVC
PETG is better in transparency, gloss, and is easy to process, print and color, and also has environmental advantages.
PETG sheet compared with PC sheet and acrylic
PETG is easy to produce products with complex shapes and large stretches, and has excellent thermoforming properties. And the molding cycle is shorter, the required temperature is low, and the yield is high.
At the same time, the toughness of PETG extruded sheet is 15-20 times that of general-purpose acrylic, and 5-10 times that of impact-modified acrylic. It has very good bearing capacity in processing, transportation and use, and can more effectively prevent rupture.
However, its physical properties are much worse than PC, but it has higher transparency and better chemical resistance than PC, which can prevent yellowing. Does not contain BPA, burns without black smoke, and can be recycled.
PETG compared to PET
It is superior to ordinary PET in surface properties such as printability and adhesion. The transparency of PETG is comparable to that of PMMA. The hardness, finish and post-processing ability of the product 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 easy to break.
In fact, the advantages of PETG compared to PET are relatively limited, and it is not a huge change. The application in some lighter bottles and cosmetic products will have advantages over PET. It may be possible to make achievements in some special fields such as optical materials. However, if the price of PETG cannot be lowered, even under the pressure of environmental protection, it may be difficult to completely replace PET.