Analysis of Shallow Threads of Plastic Bottle Caps

Update:11 Nov 2022

During the injection molding process, the cap can be easily released from the mold without the need for mold rotation. Obviously, when designing the screw thread of the bottle cap, the thread needs to be shallow in order to allow "strong release" during the injection molding process, and there must be a moderate thread enough that the thread can cover the bottle shank thread well.

The strong release screw cap can be pasted without glue when adding a liner, and the liner can get the effective restraint of the thread, so that the legend of the bottle cap gasket is not easy to fall off.

When you want to add multiple layers of liners to the cap or have multiple possible designs for the cap (such as caps with blocked threads), strong de-threading is the first choice.

The strong screw cap has constraints on the raw materials during the injection molding process, and polyethylene and polypropylene materials are the popular choices.