Locally controlling heat flux for preventing micrometre-order deformation with injection molding of miniature products

This study introduces a method of locally controlling heat flux for preventing micrometre-order deformation with injection molding of miniature products. The experiment used a 98x98x117 mm size mold assembly to produce a box-shaped product of 30x15x6 mm with 1 mm thick walls. The mold had heat flux sensors with thermocouples embedded at depths of 0.3 mm and 0.6 mm from the surface, a sensor to measure the pressure on the phi1 mm ejecting pin, phi1 mm double wall pipe coolers, and phi1 mm bar-shaped heaters. The mold locally controlled the heat flux for each injection cycle or mold zone. The control improved the straightness of the miniature product from 20 mum to 3 mum.