Incomplete sintering (cold island zones) appears in large PTFE sintered parts

Unsintered cold islands exist in the core of large cylindrical products after sintering. This problem is relatively common in sintering molding production and requires comprehensive analysis and solution from multiple aspects of material, process, and equipment.

(1) Process factor: The thermal conductivity of PTFE is extremely low (about 0.25 W/m·K), This factor affects the '2079851475616104453 and final quality of the product. (2) Process time aspect: When the diameter of large parts exceeds 300mm, the center requires an extremely long time for heat conduction, Improper time control causes the reaction or cooling process to fail to meet process requirements, affecting the final performance of the product. (3) Material aspect: Fluctuations in raw material performance indicators or insufficient pretreatment affect molding quality. (4) Process aspect: Control deviation of key process parameters causes the '2079851475616104453 to deviate from optimal conditions. (5) Equipment aspect: Equipment precision and maintenance status affect the stable execution of process parameters.

(1) Implementation measure: For ultra-large parts, use center drilling or a hollow core mold structure to shorten the heat transfer distance, Develop a specific operation plan based on actual production conditions, and verify the implementation effect. (2) Implementation measure: Limit the heating rate to ≤10°C/h., Develop a specific operation plan based on actual production conditions, and verify the implementation effect. (3) Process optimization: Determine the optimal process parameter window through systematic tests and establish standardized operating procedures. (4) Quality control: Strengthen process monitoring and product inspection, Establish a defect early-warning and traceability mechanism. (5) Preventive measure: Establish sound process control standards and a quality inspection system, and regularly review process data for continuous optimization.

This problem requires comprehensive analysis from multiple dimensions of material, process, equipment, and operation, and should be solved by systematically optimizing process parameters and the quality control system.