PBT 5% Agion Antimicrobial Rod

This is an unreinforced polybutylene terephthalate - a semi-crystalline thermoplastic polyester - compounded with 5% Agion silver-ion antimicrobial additive. PBT's appeal is stability: water absorption of just 0.08% in 24 hours and a low coefficient of thermal expansion mean machined parts hold size through humidity and temperature swings, with low creep under load. Tensile strength is about 8,690 psi, flexural modulus 330,000 psi and hardness Rockwell M72, with a dynamic coefficient of friction of 0.25 that supports unlubricated sliding contact. Maximum continuous service temperature is 245°F, dielectric strength 400 V/mil, and chemical resistance to chlorinated and corrosive cleaning solutions is excellent.

That profile fits food processing and packaging machinery, wash-down conveyor components, wear pads, guides, star wheels, gears, bearings, valve and pump parts, and electrical connectors. The silver-ion additive is EPA-registered as a material preservative: it suppresses bacteria, mold and mildew that cause odor, staining and deterioration of the plastic itself, and by the terms of that registration it does not protect users of the article against disease-causing organisms. PBT machines cleanly and holds tolerance with carbide tooling. Limitations: heat deflection temperature is only 130°F at 264 psi, so it softens under sustained load well below its service ceiling, and it is subject to hydrolysis in continuous steam or hot-water service.