What are the requirements for injection mold design?
1. In-depth analysis of the plastic part structure and its technical requirements. The structure of the plastic part determines the complexity of the injection mold structure, and the technical requirements of the plastic part (dimensional accuracy, surface roughness, etc.) determine the difficulty of injection mold manufacturing and molding process. Therefore, for special requirements that do not conform to plastic injection molding, or for unreasonable structural shapes, improved design solutions for the injection molded part should be proposed; otherwise, it will increase the difficulty of injection mold design, manufacturing, and injection molding process.
2. Familiarity with the technical specifications of the injection molding machine. The technical specifications of the injection molding machine restrict the size of the injection mold and the range of injection molded products that can be formed.
3. Understanding the processing and technological properties of the plastic. This includes the flow behavior of the plastic melt, the maximum flow distance ratio that the melt can reach; analyzing the flow resistance at various points in the runner and cavity, the discharge of air originally present in the mold cavity, the crystallization and orientation that may occur in the plastic within the injection mold and the resulting internal stress, the cooling shrinkage and compensation problems of the plastic, and the requirements of the plastic on the injection mold temperature, etc.
4. Considering the design and manufacturing of the injection mold, mainly addressing the following aspects:
a. The injection mold structure should be rationally selected. Based on the drawings and technical requirements of the plastic part, study and select appropriate molding methods and equipment. Combining the factory's machining capabilities, propose an injection mold structure plan, and fully solicit opinions from relevant parties for analysis and discussion, so that the designed injection mold structure is reasonable, reliable in quality, and convenient to operate. If necessary, requirements for modifying the plastic part drawings can be proposed based on the needs of injection mold design and processing, but this must be implemented only after obtaining the user's consent.
b. The dimensions of the injection mold's molding components should be calculated correctly. The molding components are the direct factors determining the shape, size, and surface quality of the plastic part, and are of great importance, requiring special attention. When calculating the dimensions of the molding components, the average shrinkage rate method can generally be used. For plastic parts with high precision and requiring control of the mold modification allowance, the tolerance zone method can be used for calculation. For large precision plastic parts, it is best to use the analogy method, measuring the shrinkage rate of the plastic part's geometric shape in different directions to compensate for the influence of certain factors that are difficult to consider theoretically.
c. The designed injection mold should be easy to manufacture. When designing injection molds, the goal should be to make the mold easy to manufacture and cost-effective. Especially for complex molded parts, it's crucial to consider whether general machining methods or special processing methods should be used. If special processing methods are employed, then how the parts will be assembled after processing must be considered and addressed during the mold design phase. Furthermore, sufficient allowance for mold modification after trial runs should be included in the design.
d. The designed injection mold should be highly efficient, safe, and reliable. This requirement involves many aspects of injection mold design, such as the gating system, mold closing mechanism, effective temperature control system, and flexible and reliable ejection mechanism.
e. Injection mold parts should be wear-resistant and durable. The durability of injection mold parts affects the overall lifespan of the injection mold. Therefore, when designing these parts, necessary requirements should be specified for materials, processing methods, and heat treatment. Pin-type components like ejector pins are prone to jamming, bending, and breaking, and these failures account for a significant portion of injection mold malfunctions. Therefore, consideration should be given to how to easily adjust and replace these parts, while ensuring that the part lifespan is compatible with the overall mold lifespan.
f. The injection mold structure should be adapted to the molding characteristics of the plastic. When designing injection molds, the molding characteristics of the plastic used should be fully understood and accommodated as much as possible. This is also an important measure for obtaining high-quality plastic parts.
The Highlight Points of Plastic Injection Molded Part Service
Our professional service includes engineering, mold making, prototyping, and tooling.
From single prototypes to OEM and ODM high-volume production, we can manage all our clients' plastic injection molding requirements.
In addition to mold making, we also provide injection molding services, compression molding services (especially for silicone rubber material compounding with various color matching and production jobs for specific product needs), and punch die production services.
Our in-house injection mold testing machines are available from 50 to 250T, and 300 to 3000T through our associated partners.
For each project's needs, we also design and provide fixture and jig making services to stabilize easily deformed parts.
Upon customer request, we also provide chrome plating, painting, ultrasonic welding, assembly, and packing/printing services.
We provide low-volume, pilot run production jobs and mass production for our customers.
