Machine Design

New Products: Low-Viscosity PBT

SuperFast (SF) grades of Crastin PBT thermoplastic polyesters come unreinforced or with 15 or 30% glass-fiber reinforcement. The materials have melt viscosities up to 43% lower than standard PBTs at 250°C and 1,000 sec-1. The 15% reinforced material has a tensile modulus of 5,800 MPa, 3.2% strain to break, and 106‑MPa stress at break. It deflects under 1.8 MPa at 200°C. The 30% reinforced material’s modulus is 9,900 MPa and it strains 2.5% before break.

The low viscosity is said to cut injection molding time by up to 30% by filling the mold more quickly. Lower melt temperatures speed heating, cooling, and demolding cycles. The material’s low viscosity facilitates the injection molding of thinner walls and more intricate flow paths.

E.I. du Pont de Nemours & Co. 1007 Market St. Wilmington, DE 19898 (800) 441-0575

TAGS: Products
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