Harm of static electricity to humans: With a very large amount of charge on the surface of an object, creating an extremely strong magnetic field in the surrounding environment, in the long term, will affect human health, especially the system. nervous system, genitourinary system, circulatory system..

Harms of static electricity in production: Films, bottles and jars are adhered to dust, products do not line up. Or cause sparks leading to fire and explosion. The ink is smudged (crow's feet, beard pulling...). The amount of waste increases due to static electricity causing position deviation when machining.

Innovation of stainless caster: the design just as normal steel. Parts are all exposed so it is easier to wash and clean to prevent dust, thread and even bacteria staying inside the wheel like other Plastic frame casters.