Analisis pengaruh holding time pada proses injection molding terhadap kekerasan material hdpe dan pp
ANALYSIS OF THE EFFECT OF HOLDING TIME IN THE INJECTION MOLDING PROGRES ON THE HARDNESS OF HDPE AND PP MATERIALS Abstract Injection molding is a method of forming thermoplastic materials where the material that melts due to heating is injected using a plunger into the mold. Holding time in the heat treatment process is one of the processes carried out with the aim of obtaining a high hardness value from a material. The purpose of this research was to determine the printing procedure with holding time and determine the effect oh holding time on defects, depreciation and hardness oh HDPE and PP. The measurement results at a holding time of 18 seconds produced an average hardness level of 57.13 shore D, while at a holding time of 20 seconds the average hardness level of the test object was 54.26 shore D. Depreciation using an injection molding machine at a holding time 18 seconds the average was 0.06%, while for a holding time of 20 seconds the average was 0.045%. There were 3 material defects that occur in HDPE and PP materials, namely short shot, flashing, and sink mark defects.