PETG (Glycol-modified PET; Copolyesters)



Typical Applications
PETGs offer a desirable combination of properties such as clarity, toughness, and stiffness. Applications include:


Injection molding processing conditions
 
Drying:   Drying is essential for PETG prior to injection molding. The moisture level must be below 0.04%. Drying temperature is not to exceed 66 C (150 F). Drying at approximately 65 C (149 F) for 4 hours is recommended. 
Melt Temperature:  220 - 290 C (428 - 554 F); The melt temperature is grade specific 
Mold Temperature:  10 - 30 C (50 - 86 F); Recommended: 15 C (60 F) 
Injection Pressure:  300 - 1,300 bar (4,350 - 19,000 psi) 
Injection speed:   High speeds without causing embrittlement 


Chemical and Physical Properties
PETGs (or copolyesters) are glycol modified PETs; the modification is done by adding a second glycol during polymerization. The resulting molecular structure is irregular and the resin is clear and amorphous with a glass transition temperature of 88 C (190 F). PETGs can be processed over a wider processing range than conventional PETs and offer good combination of properties such as toughness, clarity, and stiffness.


Major Manufacturers