Haojun Mould in brief: the selection principle of plastic mold structure and plastic mold parting surface


With the rapid development of the plastics industry and the continuous improvement of general and engineering plastics in terms of strength, the application range of plastic products is also expanding, and the amount of plastic products is also increasing. Therefore, plastic molds have emerged. Plastic molds are tools that are matched with plastic molding machines in the plastic processing industry to give plastic products a complete configuration and precise dimensions. Due to the wide variety of plastics and processing methods, and the complex and simple structures of plastic molding machines and plastic products, the types and structures of plastic molds are also diverse. The main performance of the plastic mold requires that the quality of the mold plays a role in guaranteeing the quality of the product in the molding process of the plastic film. Different types of plastic products and the molding process of different products have different requirements for the material, performance, and shape of the mold. Driven by high technology and the application of pillar industries, my country’s plastic molds have formed a huge industrial chain, from the upstream raw and auxiliary materials industry and processing and testing equipment to the downstream machinery, automobiles, motorcycles, home appliances, and electronic communications. , Construction and building materials and other major application industries, the development of plastic molds is full of vitality.

Below, Haojun Mould will introduce the plastic mould structure, the selection principle of parting surface and the design process.

Plastic mold structure

1. Pouring system

The channel that leads the plastic from the nozzle of the injection machine to the cavity is called the pouring system, which is composed of a main flow channel, a runner, an internal gate, a cold slug and other structures, and is composed of a casting sleeve of the parts, a drawing rod, etc.

2. Molded parts

It is a variety of parts that directly constitute the shape and size of the plastic part. It is composed of a core (internal shape of the molded plastic part), cavity (external shape of the molded plastic), molding rod, inserts, etc.

Three, structural parts

The various parts constituting the part structure play the role of installation, guidance, mechanism action and temperature adjustment in the mold. Guide parts: guide post, guide sleeve. Assembly parts: positioning gap, fixed mold bottom plate, fixed mold plate, movable mold plate, movable mold backing plate, mold foot cooling and heating system

Selection principle of plastic mold parting surface

1. The general principle of parting surface selection

The selection of the parting surface is not only related to the molding and demolding of the plastic part, but also involves the mold structure and manufacturing cost. Therefore, it is necessary to pay attention to the selection of the parting surface. Generally speaking, there are three main general principles for the selection of parting surfaces:

1. Ensure the quality of plastic parts. This is the most basic one, and the quality of the plastic parts must meet the predetermined requirements.

 2. Facilitate demoulding of plastic parts. It is easy to demould, can improve productivity, plastic parts are not easy to be deformed, and improve the rate of genuine products.

3. Simplify the mold structure. For the same plastic part, because of the different parting surface selection, the complexity of the structure is very different. A reasonable choice can simplify the mold structure.

2. How to choose parting surface

The relationship between the cavity and the mold can basically be divided into three categories: the cavity is completely in the movable mold; the cavity is completely in the fixed mold; the cavity is in the movable and fixed molds respectively. Due to the various shapes of plastic parts, there are many changes in the selection of parting surfaces. In order to give everyone a basic understanding of the selection of parting surfaces, the following introduces some typical parting surface options.