How to ensure the quality and safety of plastic molds
1. High requirements for machining accuracy
Usually the mold is composed of a die, a punch and a mold base, and some can also be multiple assembled modules. In this way, the combination of upper and lower molds, the combination of inserts and cavities, and the splicing of modules all require high machining accuracy. The dimensional accuracy of precision molds is generally in the micron level.
2. Complex shape
For some products such as car covers, aircraft parts, toys, household appliances, etc., the surface of the shape is composed of a variety of curved surfaces, so the cavity surface of the mold is more complicated. Certain surfaces must be processed mathematically.

The classic adjustment method of plastic injection speed:
One section: straight rubber mouth and horizontal rubber mouth, using medium and high speed.
Second stage: use low-speed pressing jet pattern near the injection port, silver pattern.
Three-stage: high-speed welding is used to prevent flow marks.
Stage 4: In order to reduce the scorching of the gas, the front can be switched to the pressure-holding position correctly, and the medium speed and low speed are adopted.
Two: the role of plastic injection screw.
The screw has the functions of conveying, mixing, venting, dehumidifying, melting and measuring raw materials.

The design and manufacture of injection molds for plastic molds mainly solve the following problems:
Reasonably choose the structural form of the injection mold; in order to design an injection mold with a reasonable structure, reliable quality and convenient operation, according to the drawings and technical requirements of plastic products, research and select appropriate molding methods and equipment, and propose a structural scheme for the injection mold , and fully solicit the opinions of relevant parties for analysis and discussion. According to the needs of mold design and processing, the plastic parts can be modified, but the modification can only be carried out with the consent of the user.

When processing plastic molds, in order to improve the accuracy of the mold. First of all, it is necessary to know which aspects affect the processing accuracy of plastic molds.
1. Dimensional accuracy.
It is used to indicate the degree of matching between the actual size of the workpiece being machined and the center of the tolerance zone.
Dimensional tolerances are used to control dimensional accuracy. Dimensional tolerance is the allowable variation in part size during cutting. When the basic dimensions are the same, the smaller the dimensional tolerance, the higher the dimensional accuracy.
2. Shape accuracy.
The actual geometry of the machined part surface corresponds to the desired geometry. There are six items for evaluating shape accuracy: straightness, flatness, roundness, cylindricity, and linearity. The shape tolerance is used to control the shape accuracy.

Injection molds are almost always formed in batches during the injection molding process. At this time, the injection mold processing method and process are particularly important. If the injection mold is not processed according to the specified requirements, it is very likely to damage the injection mold. To this end, the plastic industry provides an analysis of the injection mold processing method: generally, no boring raw materials are required. In some cases, they are baked at 80°C for 2 hours; the molding temperature range is large, the heating, melting, curing speed is fast, and the molding cycle is generally short; temperature parameters: the barrel temperature is around 200°C, and the material temperature is too high. If it is too high, it is easy to show silver threads, and the material temperature is too low, resulting in poor transparency.

Die injection molding is a processing method used for mass production of some complex shape parts. The specific principle is: push the heated and melted plastic raw material into the cavity of the plastic mold with the screw of the injection molding machine under high pressure, and after cooling and solidifying, the plastic molding product is obtained.
The plastic mold consists of a movable mold and a fixed mold. The movable mold is installed on the movable template of the injection molding machine, and the fixed mold is installed on the fixed template of the injection molding machine. During injection molding, the movable mold and the fixed mold are closed to form the casting system and cavity. When opening the mold, separate the movable mold and the fixed mold to take out the plastic product.