The threads on plastic bottle caps are divided into internal threads and external threads. The internal thread on plastic bottle caps is usually formed with a threaded core, while the external thread is formed with a threaded ring. Due to the special nature of threads, the mold structure of the threaded part varies, and the ways in which the threads are released also vary.
For the internal thread of plastic bottle caps, if the structure allows, it can be designed as segmented internal threads. From the perspective of mold structure, if space allows, a diagonal push rod can be used to pull the core inside to form segmented internal threads. The main forming methods for the complete internal thread on plastic bottle caps are:
(1) The method of forced demolding is adopted, but it is required that the plastic structure allows it, and plastic with good elasticity is used.
(2) The threaded core is made into a movable insert and manually demolded outside the mold. Although the mold structure is simple, production efficiency is low and labor intensity is high, which cannot be achieved