PETG processing conditions

Generic Class

PETG (Glycol-modified PET; Copolyesters)

Typical Applications

PETGs offer a desirable combination of properties such as clarity, toughness, and stiffness. Applications include medical devices (test tubes and bottles), toys, displays and lighting fixtures, face shields, and refrigerator crisper pans.

Injection molding processing conditions


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)

Material Injection Pressure

30 -130 MPa

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 material 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.