Worksite Improvement Case Studies

The Plastic Molding Workplace

Heat leads to hose collapse, preventing stable supply of raw materials

Hoses used for transfer of PET resin at drying temperatures of 80°C to 100°C collapsed due to the heat, preventing the stable supply of raw materials and leading to frequent mold defects. As well, static electricity was generated from the powder transfer, adhering the raw materials to the hose interior so that the materials mixed during changeover and contaminated the product with foreign matter, which also required countermeasures.

Hose interior material wears away, causing holes and requiring frequent hose replacement

The interior material of the resin pellet transfer hose tended to wear away, leading to holes and requiring frequent hose replacement. The worn material contaminated the product as well, leading to product loss and reducing the yield.

During a color pigment changeover, static electricity causes pellets to get stuck in the hose, causing products with different colors to get mixed together.

A plant producing curved mirrors uses PVC duct hoses to convey pellets. When they switched colors, pellets would get stuck inside the duct hose due to static electricity, and the customer needed to find a solution that would reduce the losses they were incurring.

Static electricity causes raw materials to cling, reducing work efficiency.

A manufacturer of consumer electronics, 100-yen goods and other products had the problem of static electricity easily occurring in hoses conveying raw materials between storage tanks and hoppers. The workers were all skittish about touching the products and equipment, and the raw materials would cling to the inside of the hose, resulting in poor work efficiency.

Water dripping from the hoses of a injection machine onto the floor makes the workplace floor slippery and unsafe to walk.

A customer had the problem of water always dripping from the hoses they were using. They wrapped the coolant hoses with polystyrene, but condensation still leaked onto the floor from breaks in the wrap, making the floor slippery and dangerous to walk on.

Raising the mold temperature causes liquid to leak onto the product, resulting in product defects.

To reduce the defect rate, a customer raised their die temperature from between 60 and 80℃ to between 80 and 95℃. This temperature increase however, caused the rubber hose circulating the hot water for regulating die temperature to become brittle sooner than expected. This resulted in cracks, and hot water leaking onto the product again, causing more product loss.