5 Characteristics Of Injection Mold Manufacturing

Compared with other types of molds (such as stamping molds and die-casting molds), injection molds have 5 obvious characteristics.

1. Difficult handling of mold cavity and core

The external and internal shapes of the plastic part are directly formed by the cavity and core. These complex three-dimensional surface treatments are relatively difficult, especially the forming surfaces in the blind holes of the cavity. If the traditional injection mold manufacturing method is used, the mold manufacturer is required to have a high technical level, many auxiliary fixtures, many tools are required, and the injection mold manufacturing cycle is long.

2. High requirements for accuracy and surface quality, requiring long service life of injection molds

At present, the dimensional accuracy of general injection molded parts is IT6-7, and the surface roughness is Ra0.2-0.1m. The dimensional accuracy of the corresponding injection mold parts is required to reach IT5-6, and the surface roughness Ra is less than 0.1m. The surface roughness recorded by the laser disc should reach 0.02-0.01 m at the level of mirror processing, and the mold surface roughness should be less than 0.01 m.

Long-life plastic injection molds are very important to improve injection efficiency and reduce injection costs for mass injection. At present, the service life of injection molds generally requires more than one million times. The precision injection mold uses a rigid mold base, which increases the thickness of the template and adds support columns or conical positioning elements to prevent the mold from deforming under pressure. The internal pressure sometimes reaches 100 MPa. The ejection device is an important factor affecting the deformation and dimensional accuracy of plastic products. Therefore, a good ejection point should be selected to make the demoulding uniform. The manufacturing of most high-precision injection molds is inlaid or fully assembled in the structure, which greatly improves the machining accuracy and interchangeability of mold parts.

3. Tight injection molding time

For injection molded parts, most parts are matched with other plastic parts to form a complete product. In many cases, other parts have been completed, and there is an urgent need to wait for the injection molded parts to come to market. Due to the very high requirements for the shape or dimensional accuracy of plastic products, and due to the different characteristics of resin materials, it is necessary to repeat the mold test and correct the mold after injection molding, so the lead time for development and injection mold is very tight.

4. Plastic product design and injection mold processing

Injection mold manufacturing is not the ultimate goal, but the finished product design is proposed by the product company. Injection mold manufacturers design and manufacture plastic injection molds according to the requirements of the product company. In some cases, mold design and injection molding of plastic products are not in the same injection molding plant. This has led to the design of plastic parts, mold design and mold manufacturing, and injection molding in different injection molding plants.

5. Professional division of labor, dynamic combination of injection molds

Small batch injection mold manufacturing usually belongs to the manufacture of single-piece molds. But injection molds require many standard mold parts, from the mold base to small thimbles. These cannot be done by only one manufacturer, and the manufacturing process is complicated, with universal equipment and numerical control. The equipment is extremely unevenly used.