Quality

Quality is of the utmost importance as quality molds yield quality parts.

The inspection items of injection mold generally include specifications, shape, net weight, license plate identification, chemical composition analysis, strength, macrostructure, non-metallic inclusions, ultrasonic testing, surface quality, grain size, unique components and other indicators. Naturally, the actual inspection indicators of different types of injection molds are different. The first “chemical composition analysis” is the key test for the composition of non carbon steel: carbon, silicon, manganese, phosphorus, sulfur, chromium, nickel and copper, while the pre hardened round steel is used to test carbon, silicon, manganese, phosphorus, sulfur, chromium, molybdenum, nickel, vanadium, copper and hydrogen. The content of carbon, silicon, copper, chromium, molybdenum, nickel and vanadium in corrosion resistant steel is the key test.

injection molding quality control

How to Improve the Quality of Injection Mold

Mold is the mother of industry, and the development of mold industry is related to the entire industrial level. With the development of science and technology, the requirements for molds are also constantly improving, so we must pay attention to the quality of molds when manufacturing molds. How to improve the quality of injection molds, the following points are the key.

1. The design should be reasonable. The structure should be optimized. The designer must consider the production process and plasticity when designing.

2. The mold design is the most important step to improve the mold quality, and many factors need to be considered, including the selection of mold materials, the usability and safety of mold structure, the processability of mold parts, and the convenience of mold maintenance. These should be considered as comprehensively as possible at the beginning of the design.

① The selection of mold materials should not only meet the customer’s requirements for product quality, but also take into account the cost of materials and their strength in the set cycle. Of course, the selection of materials should also be based on the type of mold, the use of working methods, processing speed, main failure forms and other factors. For example, the main failure form of blanking die is edge wear, so it is necessary to select materials with high surface hardness and good wear resistance; Stamping die mainly bears periodic load, which is easy to cause surface fatigue cracks, leading to surface peeling, so it is necessary to choose materials with good surface toughness; The drawing die shall be made of materials with very low friction coefficient; Because the die-casting die is subjected to cyclic thermal stress, the material with strong thermal fatigue should be selected; For injection mold, when the plastic parts are made of ABS, PP, PC and other materials, the mold material can be pre hardened and tempered steel; when the plastic parts are made of high finish and transparent materials, the corrosion resistant stainless steel can be selected; when the products are in large batches, the quenched and tempered steel can be selected. In addition, it is also necessary to consider the use of mold materials with less affinity to the parts, so as to prevent mold sticking from aggravating the wear of mold parts, thus affecting the quality of the mold.

② When designing the die structure, try to be compact and easy to operate, and ensure that the die parts have sufficient strength and stiffness; When the die structure allows, the corners of each surface of the die parts shall be designed as fillet transition as far as possible to avoid stress concentration; For female die, cavity and part of punch and core, combined or inlaid structure can be used to eliminate stress concentration. For slender punch or core, appropriate protective measures shall be taken in structure; For the cold stamping die, a device (such as spring pin, compressed air, etc.) shall be provided to prevent blocking of parts or wastes. At the same time, we should also consider how to reduce the impact on the quality of the mold caused by the wear of sliding fit parts and frequently impacted parts in long-term use.

③ In the design, it is necessary to reduce the scope of disassembly and assembly for maintenance of a certain part, especially for replacement of wearing parts, so as to reduce the scope of disassembly and assembly as much as possible.

3. Master the method and precision of mold processing. The accuracy of each component directly affects the overall assembly of the mold. In addition to the accuracy of the equipment itself, it is necessary to improve the processing method of the parts and improve the technical level of the fitter in the mold grinding process to improve the processing accuracy of the mold parts; If the overall assembly effect of the mold fails to meet the requirements, the probability of the mold moving in an abnormal state will be increased in the mold test, which will have a great impact on the overall quality of the mold. Reasonably select high-precision processing methods, such as EDM, wire cutting, CNC processing, etc., and pay attention to the accuracy inspection of the mold, including the processing accuracy and assembly accuracy of mold parts and the comprehensive inspection of the mold accuracy through mold testing and acceptance. In addition, high precision measuring instruments should be selected as far as possible during the inspection. For mold parts with complex shaped surface and curved surface structure, if a common ruler The vernier card cannot achieve accurate measurement data. At this time, it is necessary to select precision measuring equipment such as coordinate measuring instrument to ensure the accuracy of measurement data.

4. Strengthen the mold surface and improve the wear resistance of the mold. Nitriding (hard nitriding) treatment can be used for plastic mold steel parts to improve the wear resistance, heat fatigue resistance and corrosion resistance of the parts; The drawing die and bending die can be treated by sulfurizing to reduce the friction coefficient and improve the wear resistance of materials; Carbonitriding (soft nitriding) can be applied to the surface strengthening treatment of various moulds.

5. Mold maintenance shall be done well. When using the mold correctly, it is also necessary to conduct regular maintenance for the mold. The guide pillar, guide sleeve and other parts with relative movement of the mold should be regularly filled with lubricating oil. For the forging mold, plastic mold, die-casting mold and other molds, the lubricant or mold lifting agent should be sprayed on the surface of the formed parts before each mold is formed. Planned protective maintenance of the mold and data processing in the maintenance process can prevent problems that may occur in the production of the mold and improve the maintenance efficiency.

In a word, in order to improve the quality of the mold, first of all, each link must take into account the impact on the quality of the mold, and secondly, through the cooperation of all departments. The quality of mould is the true embodiment of the strength of mould enterprises.

Win Win Mold is sparing no effort on each process to ensure the quality.
1. Mold Design Control
2. Mold Steel Hardness Inspection
3. Mold Electrodes Inspection
4. Mold Core and Cavity Steel Dimension Inspection
5. Mold Pre-Assembly Inspection
6. Mold Trial Report and Samples Inspection
7. Pre-Shipment Final Inspection
8. Export Product Package Inspection

We are confident that our QA team will ensure the quality of your projects with the newest manufacturing and inspection equipment. We guarantee our tooling will meet tough tolerances and will consistently deliver quality parts with the shortest cycle time.