What are the advantages and disadvantages of PETG?

Time:2022-08-09 16:30:20

PETG/ PCTG is a non-crystalline copolyester. During its production, since a certain amount of ethylene glycol is replaced by 1,4-cyclohexanedimethanol (CHDM), crystallization can be prevented, thereby improving manufacturing and transparency. Its products are highly transparent and have excellent impact resistance, and are especially suitable for forming thick-walled transparent products, and can be designed in any shape according to the designer's intention. It can adopt traditional extrusion, injection molding, blow molding and other molding methods, while PETG/ PCTG products have excellent post-processing properties and can be modified by conventional machining. At the same time, the copolyester has passed the food contact standard of the US FDA, so it can also be used in food, medical and health fields.


First of all, it is a transparent material, so the following transparent materials are often chosen for comparison.

1) PETG / PCTG It is first of all a highly transparent plastic. It has excellent optical properties, high gloss surface and low haze, and its light transmittance is close to 90%, which is close to that of acrylic (pmma) and better than that of polycarbonate (PC).

2) PETG/PCTG has a wider range of chemical resistance (such as coffee, chocolate, oil, acid, etc.). It has excellent chemical resistance to the following chemicals: automotive oils, liquid soaps, detergents, cleaners, carpet cleaners, toothpaste and peppermint oils, perfumes, cooking oils, 2-propanol, hydrocarbon solvents, etc. ,

3) It is one of the few environmentally friendly plastic materials so far. The reason why it is said to be an environmentally friendly material is that only CO2 and water are left after it is burned, which can protect the nature very well. Since 2006, many developed countries such as Europe, America 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. Once your customers propose to use environmentally friendly plastics, PETG should be the first choice.

4) PETG/PCTG is especially suitable for molding transparent products with thick wall. The light transmittance of PETG products with thick walls can also keep the same excellent, and PETG/PCTG products have a transparent ice blue background that caters to the world trend, and their surfaces are extremely delicate and have super visual effects; Or inside the solid product, it is not easy to generate air bubbles during processing. (We have many transparent samples for our guests to see, and these samples belong to the major brands).

5) PETG/ PCTG has extremely high toughness, excellent tensile properties and good impact resistance. Among transparent plastics, PC has the best toughness and impact resistance, but poor tensile properties; acrylic has poor tensile properties, toughness and impact resistance; and PETG has extremely high toughness and excellent tensile properties. Its maximum tensile ratio can reach more than 180%, and its impact strength is several times that of acrylic, but slightly worse than that of PC. At the same time, PCTG is a wide range of transparent plastics, and its impact strength is closer to PC. One of the plastics, PCTG has the reputation of "not rotten", which is derived from its super toughness.

The super toughness greatly reduces the rupture of the finished product during secondary processing, transportation, installation and use, and greatly reduces the overall cost of the finished product. Another outstanding advantage of PETG/ PCTG is: Its physical and mechanical properties hardly change at low temperature

6) They have fun secondary machining properties. Excellent ductility enables multiple secondary processing of PETG/PCTG. You can laser cut, edge milling, die cutting, drilling, welding, punching, hot bending, cold bending (limited to 2.5mm or less), screw/rivet/bolt connection or fixation on their products. And the PC's secondary The processing performance is poor, the reason is that PC is more prone to stress concentration during molding. Once one of the above secondary processing methods is performed, the stress balance of PC products will be broken, or the product will be cracked.

7) They have excellent printing performance and coating performance. That is to say, the surface of PETG/PCTG plastic products can be printed (spraying, silk-screen printing, pad printing, hot embossing, etc.) or sprayed without any special corona treatment, and the adhesion performance with the surface coating Very good (Note: Although the chemical resistance of PETG/ PCTG is broad, it cannot guarantee the resistance to all solvents in the sprayed material, please customize the spraying material suitable for PETG/ PCTG in advance).

8) They have excellent adhesive properties. There can be a variety of random bonding methods: such as general solvents, general adhesives, friction bonding, high-frequency bonding, ultrasonic bonding, mechanical bonding (such as screws, rivets), etc. (Note: Please test by yourself Suitable adhesive for PETG/ PCTG)

9) PETG/PCTG has excellent low temperature resistance. They can be used normally at -30 ℃, and the lowest temperature can even reach -60 ℃, so its products are very suitable for some alpine regions (such as Russia, Canada, etc.), and its other characteristics are also maintained at low temperatures. Outstanding.

10) ) They have good injection molding properties. The PETG/PCTG injection molding process is relatively stable and does not require a specially designed injection molding machine. The injection temperature is only about 215℃~235℃, while the PC injection molding process is not easy to control, and the injection temperature is as high as about 280℃. They can save power better.

PETG/PCTG is not easy to generate internal stress during injection molding, which is determined by their molecular structure and its excellent ductility. The PC is easier to generate internal stress, and there is an additional post-processing procedure to eliminate the internal stress. The internal stress of injection molded products is very harmful, and the serious case is stress cracking, which will increase unnecessary complaints or claims from customers.

  shortcoming :

1) The heat distortion temperature is too low, only 75 degrees, which will bring many changes.

2) Drying is more troublesome and difficult to dry.