This kind of miniature parts die casting is more favor of zinc die casting, because they require a complex geometry and precision dimension, with a strong strength, durable as well. On the surface of the metal ball is designed with many slots so that enhancing fraction power between plastic cover and metal body. Avoid have a bad rotation when the rubber wrapping metal ball is operated by human. Added the TPU cover soft feeling, making have a mild feeling. This design is The Technique Of Supporting Casting Zinc Alloy With Hot chamber Die Casting Machines, it will finish the project in perfect.
In order to enclose the metal ball fully with rubber, these metal ball should be heated with heating machine before injection. The TPU melt point is at 220 degrees,zinc alloy melt point is much over it. So we don’t worry about it. When using wrapping rubber the zinc casting ball, you should warm up the ball to 120 degrees to match with cold shrinkage of TPU material during plastic injection, which is also the reason that scratches produce on the surface of wrapping cover. So we should be attended of difference of temperature between plastic and metal.
Putting the heated metal ball into plastic injection mold, At this time, the mold designing should consider of draft angles adjustment and ensure the mold can be opened smoothly, meanwhile being sure that the surface of the injected combined body is smooth, even thickness plastic layer on the metal ball. Improving the imperfection rate of the mass production.
The wrapping rubber zinc die casting ball is ejected, they should be inspected. The operator use his own eyes to find some defect goods from the mass production. They find that some goods have blank area and scratches on the injected ball, and adjust that they are defect ones, and require to separate from all goods, put two different area respectively.
Packaging the good quality wrapping rubber zinc die casting balls into plastic bag and ready for shipment in accordance with client requirements. This is last operation procedure. We choose high quality plastic bag to pack these good quality finished goods.