Structural factors and related knowledge to be considered in plastic mold design

Plastic mold design is based on correct plastic product design, and mold design and manufacturing are closely related to plastic processing. The success or failure of plastic processing depends largely on the effect of mold design and the quality of mold manufacturing. The structural elements that need to be considered in plastic mold design are:

1. Parting surface, that is, the contact surface where the die and the punch cooperate with each other when the die is closed. The selection of its position and form is affected by factors such as product shape and appearance, wall thickness, molding method, post-processing technology, mold type and structure, demolding method and molding machine structure.

2. Structural parts, that is, sliders, inclined tops, straight top blocks, etc. of complex molds. The design of structural parts is very critical, which is related to the life of the mold, processing cycle, cost, product quality, etc. Therefore, designing a complex mold core structure requires a higher comprehensive ability of the designer, and pursues simpler, more durable and more economical as far as possible. Design.

Mold structure design

The plastic parts are small in size and low in product precision, requiring good performance, no cracks, bending resistance, and mass production. This mold is designed as a one-mold eight-cavity structure, and the following problems are solved

1. The balance problem of the gating system In the design of multi-cavity molds, all cavities are fed at the same time as possible. Due to the increase in the number of cavities, the length of the runner must increase, and the injection pressure will increase before the melt reaches the cavity. And the heat of the melt will be greatly lost. If the design of the shunt channel is slightly unreasonable, there may be defects in the plastic parts, such as one or several cavities are not filled, or they are filled immediately, but there are problems such as poor welding or internal organization. Looseness and other defects, if the injection pressure is increased, it is easy to produce flash. The design of the runner in the paper adopts an unbalanced arrangement. By setting the size of the gate and the runner, the injection process is adjusted to the value to ensure that the shrinkage rate of each cavity is consistent, and the plastic parts with the highest precision requirements are guaranteed to be mutually compatible. The location of the gate is set at the thick end of the plastic part and marked as the Y end, which is conducive to flow and feeding, and can also avoid the generation of weld lines. The molecules have orientation to meet the requirements of bending and not breaking.

2. Design of the cooling system The design principle of the cooling device is to design the cooling device without increasing the structure of the mold itself. Under the premise of satisfying the transfer area required for cooling and the mold structure, the number of cooling circuits should be as large as possible. Multi-design, and the diameter of the cooling channel is as large as possible. The cooling water holes are machined on the upper and lower cavity plates and the movable and fixed platens. During installation, the cooling water holes of the upper cavity plate are connected to the water holes of the fixed platen, and then sealed with a sealing ring. , The cooling water hole of the lower cavity plate is docked with the water hole of the movable template, and it is also sealed with a sealing ring. The water holes are arranged on the upper and lower cavity plates and the movable and fixed template.

Taizhou Huangyan Mengsheng Plastic Mould Co., Ltd. is Mould Manufacturers. Industrial Equipment Parts Mould Manufacturers

Founded in 1994, MS own more than 40 sets of advanced imported equipment including CAD and CAM machining centers, CNC machining center, high speed CNC, double-head EDM and high-speed carving machines, as well as a self-provided 300-7,000g imported injection molding machine for mold testing and production.

Our major products are molds including air coolers, auto logos, pallets, dustbins, chairs, stools, turn crates, storage boxes, water tanks, pet products which are well sold in China, Europe, America, Africa, Middle East and Southeast Asia.