Process analysis of plastic mold products. Before designing, we must first conduct a comprehensive analysis and research on the performance of the plastic mold product, and carefully discuss with the plastic mold manufacturer to reach an agreement. During this process, the product geometry, dimensional accuracy and appearance requirements need to be discussed to avoid unnecessary complexity in mold making.
Mold structure design. A good mold requires not only good processing equipment and skilled molds, but also good mold design, especially for complex molds. Mold design quality accounts for more than 80% of mold quality.
The mold design is: under the premise of meeting customer requirements, the processing cost is low, the processing difficulty is high, and the processing time is short. Therefore, we must not only fully digest the needs of customers, but also understand the injection molding machine, mold structure, processing technology and the processing capacity of the mold itself. Therefore, in order to improve the level of mold design, the following operations should be performed.

The ideal scrap should have a reasonable crushing angle and a uniform bright band. This keeps the stamping pressure as small as possible, creating a neat round hole with the smallest burr. Therefore, in order to prolong the service life of the mold, the clearance should be increased considering the quality of the finished hole.
Selection of plastic mold gap. The die gap is related to the die material and thickness. Not having a reasonable interval can lead to the following problems:
(1) If the gap is too large, the burr of the stamping part is relatively large, and the stamping quality is poor. If the gap is too small, although the punching quality is good, the die wear is serious, the die life is greatly reduced, and the punch is prone to breakage.
(2) If the gap is too large or too small, it is easy to cause bonding to the punching material, resulting in the formation of strip-shaped material during punching. If the gap is too small, a vacuum is likely to be formed between the bottom surface of the punch and the plate, and the waste material will rebound.

How do plastic mold manufacturers deal with white edges? Generally, people who do not understand this profession first consider changing materials. Why do you say that? Because this is a method that many people who do not understand plastic injection processing know, but this method has a drawback, which is waste. Is there no other solution other than changing the material? So how is the white border formed?
White edge is a unique injection defect of modified polyethylene and plexiglass, mainly on the edge of the part near the parting surface. The white edge is an aggregate composed of many tiny spaces between directly stretched oriented molecules and the flow direction. There is still a polymer link phase in the direction of the white edge, so the white edge is not a crack. Under proper heating, the stretched-direction molecules may return to their natural bending state, causing the white edge to drop.

The so-called parting surface is to open the mold and take out the surface of the product. The choice of fractal surface is also the mold design, which is affected by many factors such as product shape, appearance, wall thickness, dimensional accuracy, and the number of holes. Whether the selection of the parting surface of the mold is reasonable is related to the life of the mold, the structure of the mold and the molding of the plastic parts, which are all very important links.
​ 1. It is beneficial to the processing and manufacture of plastic mold inserts, inner molds or other molding parts. Conducive to plastic mold matching.
2. The parting surface of the plastic mold should be as simple as possible without skipping too much. If there are too many steps, not only the processing of injection mold parts is difficult, but also the difficulty of clamping the mold will be greatly increased.

Selection of plastic mold gap. The die gap is related to the die material and thickness. Not having a reasonable interval can lead to the following problems:
(1) If the gap is too large, the burr of the stamping part is relatively large, and the stamping quality is poor. If the gap is too small, although the punching quality is good, the die wear is serious, the die life is greatly reduced, and the punch is prone to breakage.
(2) If the gap is too large or too small, it is easy to cause bonding to the punching material, resulting in the formation of strip-shaped material during punching. If the gap is too small, a vacuum is likely to be formed between the bottom surface of the punch and the plate, and the waste material will rebound.

Classification of mold materials
According to the different conditions of use, mold materials can be divided into several categories, such as cold working mold materials, hot working mold materials, plastic mold materials and other mold materials, each category is divided into several sub-categories.
Cold working mold materials are widely used, and their main performance requirements are strength, hardness, toughness and wear resistance. In recent years, the use of carbon tool steel has become less and less, and the proportion of high alloy steel molds is high. Cold die steels are mainly high carbon alloy steels, all of which are heat-treated reinforced section steels with a hardness higher than 58HRC. Low-alloy cold-worked die steel, usually 9CrWMn, is generally only used for simple dies and low-impact trial dies for small batch production. Cr12 type high carbon alloy steel is a common material for most molds. This steel has higher strength and wear resistance and lower toughness.

The mold must not only have high machining accuracy, but also have good machining quality. Generally, the tolerance range should be controlled in the micron level. Only a high-precision mold can ensure that the product reaches a certain accuracy and the qualified rate of the product, and it is possible to prolong the use of the mold. Long service life, the mold is a relatively expensive process equipment, and its processing cost accounts for about 10% to 30% of the cost, so it is more meaningful to require a long service life of the mold.
This is mainly to meet the requirements of production and the market competitiveness of products. The cost is low. The cost of the mold is related to the complexity of the mold structure, mold material, manufacturing accuracy requirements and processing methods. Therefore, it is necessary to reasonably design and formulate the processing technology, select appropriate processing equipment, and ensure low processing costs.

The application scope of plastic products is constantly expanding, such as: household appliances, instrumentation, construction equipment, automobile industry, daily hardware and many other fields, the proportion of plastic products is increasing rapidly.
These various products are produced through plastic molds.
Today we will introduce the plastic injection molding process.
Molds are tools used to produce plastic products. It consists of several groups of parts with mold cavities. In the injection molding process, the mold is clamped on the injection molding machine, the molten plastic is injected into the mold cavity, and molded in the mold cavity, then the upper and lower molds are separated, and the product is discharged from the mold. The cavity leaves the mold through the ejection system, and the mold closes. For the next injection, the entire injection molding process is cyclic.

The mold meets the process performance requirements
Dies are usually manufactured by forging, cutting, heat treating and other processes. In order to ensure the quality of the mold and reduce the production cost, the material should have good forgeability, machinability, hardenability, hardenability and grindability; it should also have small oxidation, decarburization sensitivity and quenching deformation cracking tendency.
The mold meets the economic requirements
When selecting molds, economic principles must be considered to keep manufacturing costs as low as possible. Therefore, on the premise of satisfying the performance, the first quotation is lower, carbon steel can not use alloy steel, and domestic materials can not use imported materials.