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เอกสารมาตรฐาน
สหรัฐอเมริกา
ASTM
D4745-19
Standard Classification System and Basis for Specification for Filled Polytetrafluoroethlyene (PTFE) Molding and Extrusion Materials Using ASTM Methods
2019
6
ASTM Vol.08.02 (2022)
This standard classification system and basis for specification covers polytetrafluoroethylene (PTFE) filled molding compounds made with virgin PTFE resins defined in Specification D4894, as Types II and III. NOTE 1: This system can be used as a model for other PTFE compounds having particulate fillers that can survive the sintering temperatures of PTFE as can those listed in this standard. This system is restricted to virgin PTFE base resin for technical reasons. Recycled or reprocessed material cannot be processed successfully. NOTE 2: The properties measured on commercially fabricated parts may differ from the listed values for samples prepared by the procedures given in this specification, depending on part geometry and processing parameters. Compounds used for ram extrusion are made from resins that comply with ASTM-D4745 Type II prior to their pre-sintering process. Property values measured on extruded products will vary from the listed values for Type II compounds which are prepared by the procedures given below which standardize mold diameter and sintering cycle. End users should assess these expected variations in ram extruded products to ensure their suitable use in their specific application.
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