1、 Rotary deep thread
1. In the injection molding process, the rotating equipment system in the mold can effectively maintain the integrity of the cap screw. Therefore, the screw thread shape of the bottle cap can be effectively manipulated, and the bottle cap wall will not be skewed when the screw thread of the upper bottle shank is rotated.
2. In the process of screwing the bottle cap, rotate the upper bottle shank thread to make the bottle pad close to the bottle wall, which can convert the bottle cap into linear force.
3. Since the threads of the rotating teeth can not effectively inhibit the falling off of the cover gasket, the screw cover shall be glued and posted when adding the gasket.
2、 Strong fault shallow line
1. In the process of injection molding, the bottle cap can be easily demoulded from the mold without mold rotation. Obviously, when planning the thread of the bottle cap, the thread must be a little shallower, so that it can be "strongly demoulded" during the injection molding process, and there must be enough moderate threads to perfectly cover the thread of the bottle wall.
2. The strong thread bottle cap can be posted without glue when adding the inner tank. The inner tank can be effectively restrained by the thread, so that the bottle cap gasket is not easy to fall off.
3. When you want to add multi-layer lining to the bottle cap or make various possible schemes for the bottle cap (such as screw plug type bottle cap), you will generally choose forced threading.
4. There are restrictions on raw materials in the process of injection molding, among which polyethylene and polypropylene materials are popular choices.