Plastic panel parts for car navigation systems are manufactured at plastic parts manufacture’s plant in Thailand. The customer was troubled by molding defects such as uneven coloring caused by static electricity generated in the pellets during the molding of resin parts.

When resin pellets are sucked into a hopper, the hose, pellets, and pellets repeatedly collide with each other, which generates intense static electricity on the pellets and causes a variety of problems. In this case, the degree of static electricity generated varied depending on the type of pellets (color and composition), and the degree of static electricity adsorption inside the hopper varied accordingly, resulting in a disordered mixing ratio of pellets fed into the molding machine and causing color irregularities.