PETG is an amorphous copolyester. In the production process, a certain amount of ethylene glycol is replaced by 1, 4-cyclohexane dimethano l(CHDM), which prevents crystallization, thereby improving manufacturing and transparency. Its products are highly transparent, excellent impact resistance, especially suitable for forming thick wall transparent products, and can be designed in any shape according to the designer's intention, it can use traditional extrusion, injection molding, blow molding and other molding methods, while PETG products have excellent post-processing performance, and can be conventional machining modification. At the same time, this copolyester has passed the food contact standard of the US FDA, so it can also be used in food, medical and health fields.
(Comparison of PETG characteristics with other chemical materials)
Advantages:
It is first of all a transparent material, so many times the following will choose transparent material to compare.
① PETG It is first and foremost a highly transparent plastic. It has excellent optical properties, high gloss surface and low turbidity, and its light transmittance is close to 90%, which is very close to acrylic (pmma) and better than the light transmittance of polycarbonate (PC).
(From left to right are the product drawings of PETG, PMMA and PC)
② PETG has a wider range of chemical resistance (such as coffee, chocolate, oils, acids, etc.). It has excellent chemical resistance to the following chemicals: automotive oil, soap liquid, detergent, carpet detergent, toothpaste and peppermint oil, perfume, cooking oil, 2-propanol, hydrocarbon solvents, etc.
③ PETG is especially suitable for forming transparent products with thick walls. PETG products with thick walls can also maintain the same excellent light transmission rate, and PETG products have a transparent ice blue background that meets the world trend, and its surface is extremely delicate, with super visual effects. In addition, their thick wall or solid product interior is not easy to produce bubbles during processing.
④ It is one of the few environmentally friendly plastic materials so far. The reason why it is environmentally friendly material is because it is only CO2 and water after burning, which can protect nature well. Since 2006, many developed countries such as Europe, the United States and Japan are vigorously promoting the use of environmentally friendly materials similar to PETG (PETG has SGS, FDA, MSDN certification). PETG has become one of the preferred alternatives to non-environmentally friendly transparent materials such as PVC.
⑤ PETG has extremely high toughness, excellent tensile resistance and good impact resistance. In transparent plastics, the toughness and impact resistance of PC are excellent, but the tensile property is not good; The tensile properties, toughness and impact resistance of acrylic are not good; PETG has extremely high toughness and excellent tensile properties, and its maximum tensile ratio can reach more than 180%. Its impact strength is several times that of acrylic, but slightly worse than PC. Meanwhile, PETG is one of the plastics whose impact strength is close to PC's among a wide range of transparent plastics. PETG has the reputation of "not broken", which is derived from its super toughness.
Super toughness greatly reduces the breakdown of finished products during secondary processing, transportation, installation and use, and greatly reduces the overall cost of finished products. Another outstanding advantage of PETG is that its physical and mechanical properties hardly change at low temperatures.
⑥ They have interesting secondary processing properties. The excellent ductility makes possible a variety of secondary processing methods for PETG. You can laser cut, edge milling, die cutting, drilling, welding, punching, hot bending, cold bending (up to 2.5 mm), screw/rivet/bolt connection or fixation of their products. The secondary processing performance of PC is poor, because PC is easier to produce stress concentration when forming, once one of the above secondary processing methods, it will break the stress balance of PC products, or lead to product cracking.
⑦ They have excellent printing and coating properties. That is to say, the surface of PETG plastic products can be printed (spraying, screen printing, pad printing, hot stamping, etc.) or sprayed without any special corona treatment, and the bond with the surface coating is very good (Note: PETG has a wide range of chemical resistance, but it is not guaranteed to resist all solvents in the spray, please customize PETG suitable spray in advance).
⑧ They have excellent bonding properties. Can have a variety of arbitrary bonding methods: such as general solvent, general adhesive, friction bonding, high-frequency bonding, ultrasonic bonding, mechanical bonding (such as screws, rivets).
⑨ PETG has excellent low temperature resistance. They can be used normally at -30 ° C, and the lowest temperature resistance can even reach -60 ° C, so its products are very suitable for some high-cold regions (such as Russia, Canada, etc.), and its other characteristics remain outstanding at low temperatures.
⑩ They have good injection molding properties. PETG injection molding process is relatively stable, does not require a specially designed injection machine, its injection molding temperature is only about 215 ° C ~235 ° C, and PC injection molding process is not easy to control, injection molding temperature up to 280 ° C, in contrast, they can better save power.
PETG is not prone to internal stress during injection molding, which is determined by their molecular structure and its excellent ductility. The PC is easier to produce internal stress, and more than one post-processing program to eliminate internal stress. The internal stress of injection molded products is very harmful, and the serious situation is stress cracking.
Disadvantages:
1) The thermal deformation temperature is too low, only 75 degrees, which will bring a lot of change
2) Drying is more troublesome, more difficult to dry.
