Poor dimensional accuracy in injection molded products: Is it due to mold wear or equipment precision issues?: EWay Precision Technology

Poor dimensional accuracy in injection molded products can be caused by mold wear or equipment precision issues, or a combination of both. Determining the specific cause requires analysis from the following aspects:

First, check the mold condition. After prolonged use, key parts of the mold, such as the cavity and core, will experience wear, leading to dimensional deviations. Wear on the parting line, in particular, can cause flashing and affect closing accuracy. Wear on moving parts such as ejector pins and sliders can also cause product deformation during demolding. If the mold cooling system is blocked or damaged, it can lead to uneven local temperatures and inconsistent product shrinkage. Mold maintenance records can help determine the degree of wear.

Secondly, examine equipment performance. Insufficient clamping force of the injection molding machine can lead to incomplete mold closure and dimensional fluctuations. Wear of the injection mechanism can cause unstable injection pressure, affecting the holding pressure effect. Increased clearance between the screw and barrel will reduce plasticization quality. As equipment ages, the accuracy of the control system decreases, making it difficult to maintain stable process parameters. Equipment inspection records and recent product dimensional trend charts can help determine the equipment status.

Improper production process parameter settings can also affect dimensional accuracy. Parameters such as injection speed, holding pressure, and cooling time need to be optimized according to material characteristics. Material batch differences or insufficient drying can lead to changes in shrinkage rate. Fluctuations in workshop temperature and humidity also have a significant impact on product dimensions.

The following measures are recommended: First, measure the dimensions of key parts of the mold and compare them with the design drawings to determine the amount of wear. Then, perform equipment precision testing, including clamping parallelism and injection repeatability. Simultaneously check the process parameter records for the past three months and analyze the fluctuations. If necessary, step-by-step verification of the mold and equipment can be performed, such as testing the equipment status using a spare mold, or testing the old mold on new equipment.

The final solution may include mold repair or replacement of wear parts, repair of key equipment components, and re-optimization of process parameters. Regular preventive maintenance and strict process control can effectively reduce dimensional deviation problems.