Polyethylene terephthalate (PET) has excellent chemical resistance and barrier properties, good strength, rigidity, fatigue endurance, and abrasion resistance.
Drying is essential before molding. PETs are sensitive to hydrolysis. Recommended that drying conditions are 120 C 165 C [248 F 329 F] for 4 hours. Keep moisture content at less than 0.02%
265 C 280 C [509 F 536 F] for unfilled grades, 275 C 290 C [527 F 554 F] for glass reinforced grades
30 MPa-130 MPa
High speeds without causing embrittlement
All conventional types of gates can be used. Make gates 50 - 100% of the part thickness.
PET is an aromatic polyester produced from polymerization of either terephthalic acid (TPA) or dimethyl ester terephthalic acid (DMT) and ethylene glycol (EG). The glass transition is approximately 165 C [330 F] and the material crystallizes over a temperature range from 120 C 220 C [248 F 428 F].
PET is highly sensitive to moisture at high temperatures and exhibits excessive warpage when reinforced with glass fibers. Promotion of crystallinity is achieved through adding nucleating agents and crystal growth accelerators. Crystalline moldings exhibit high modulus, gloss, and heat distortion temperatures. The addition of particulate fillers, such as mica, minimizes warpage. When low mold temperatures are used, transparent moldings can be obtained with unfilled PETs.