The design of bottle cap mold mainly includes the following aspects:
Mold type and structure:
Three-plate mold: It is commonly used in the mold design of PE material bottle caps. It adopts point gate and is set in the center of the top of the plastic part. Point gate can increase the shear rate of the melt, reduce the melt viscosity, and facilitate mold filling. At the same time, the residual trace of the point gate is small, ensuring the surface quality of the plastic part.
Multi-cavity mold: In order to improve production efficiency and reduce costs, bottle cap molds often adopt a one-mold multi-cavity design mode. For example, the design mode of 1 mold and 10 cavities is more common in bottle cap production.
Material selection:
Mold material: Bottle cap molds usually use high-strength mold materials, such as 2083, P20H, 718H, etc. The main part of the mold includes the core, cavity, stripper plate and related inserts. It uses high-grade plastic mold steel, such as 2083, 2344, 2316, etc., and is heat treated to increase hardness.
Cooling system:
Mold temperature control system: directly affects the quality and production efficiency of the product. The design of the cooling system needs to ensure that each cavity can be filled evenly at the same time. Usually, an unbalanced pouring system and a cold material hole are used to store the front cold material.
Transmission and ejection mechanism:
Transmission mechanism: For bottle cap molds with internal threads, a transmission mechanism needs to be designed to realize the rotation and translation of the thread core, so as to demold smoothly. The transmission mechanism is usually composed of a hydraulic cylinder, a gear rack, a driven gear, etc.
Ejection mechanism: The internal thread demolding mechanism needs to complete the demolding before the mold is opened to ensure that the internal thread of the plastic part can be ejected smoothly.
Design steps and process analysis:
Process analysis: According to the structure of the plastic part, process analysis is carried out to determine the design scheme, calculate the size of the working part of the mold, design the working parts, select standard parts, and finally design the general assembly drawing of the mold.
