Patent ID: 7682535

Claim:
An injection molding method for filling a closed cavity of an injection mold comprising: (a) providing a closed mold cavity; (b) providing a temperature sensor in a wall of the closed mold cavity at a location near the end of the melt flow path for directly monitoring the temperature of the mold wall near the end of the melt flow path; (c) feeding a melt to the closed mold cavity whereby the melt in the closed mold cavity is under pressure; (d) determining when the melt contacts the temperature sensor based on a sudden change in temperature resulting from the melt contacting the temperature sensor; (e) determining a changeover point after the sudden change in temperature is determined in step (d) on the basis of the monitored temperature before the mold cavity is filled with the melt; and (f) switching over to a holding pressure phase at the changeover point determined in step (e).