After the injection mold is finished processing, is it immediately put into production? The answer is definitely no. There’s a crucial step – trial molding. Before injection molding with a new mold or when changing molds for production on a machine, mold testing is an essential part. The quality of trial molding results directly affects the smoothness of subsequent factory production.
Why is Trial Molding Necessary?
You can’t judge whether a plastic mold is suitable for injection molding just by looking at it. Generally, molds are not intended to be used as final products when they are initially designed. Defects can appear after production due to various reasons. These defects can’t always be eliminated entirely before manufacturing, and issues might arise during the production process. Hence, trial molding is needed. The samples produced during trial molding are analyzed, evaluated, and optimized to meet high-quality requirements.
Defects in most molded products arise during the plasticization and injection stages, and sometimes due to improper mold manufacturing. To avoid defects caused by mold design, it’s essential to analyze mold design and process parameters during mold fabrication.
After obtaining trial molding results, operators usually need to reevaluate the mold’s condition to prevent unnecessary costs and time during the trial process. Often, to compensate for design flaws in the mold, operators might unknowingly make incorrect adjustments. Since the parameter range for producing qualified products is narrow, any deviation can result in product quality far exceeding allowable error limits.
The purpose of trial molding for injection parts is to find optimal process parameters and refine mold design. It’s not just about getting good samples. Even if factors like materials, machinery, or environment change, stable and uninterrupted batch production should still be ensured.
Drawbacks of Multiple Trial Moldings:
1. If the design of the injection mold isn’t properly reviewed, and if the injection structure has unreasonable aspects, multiple improvements might be needed after trial molding. This not only exceeds the mold budget but also yields unsatisfactory results due to repeated adjustments.
This can lead to discarding the mold and redoing the processing, causing cost overruns and delays. In some cases, even if the injection mold design is good, improper processing of large-scale injection molding can increase the number of trials and costs. This issue has led many large-scale injection manufacturers to invest more in measurement equipment.
2. During mold testing, inappropriate molding processes and injection machine models might be chosen. Large-scale injection processes might seem good, but the resulting products might not be ideal. Adding unnecessary trial rounds increases the costs. This is a common problem in small-scale injection mold factories.
3. The physical properties of plastic might not be entirely clear, including shrinkage rates, which can be inaccurate. Therefore, understanding the physical properties of plastic before designing an injection mold is necessary to effectively reduce the number of trials.
How to Reduce the Number of Mold Trials?
The number of mold trial rounds for a set of molds depends on several factors:
1. The optimization of the customer’s product structure.
2. The thoroughness of mold drawing evaluations.
3. The rationality of mold part processing arrangements.
4. The appropriateness of mold processing control.
5. The effectiveness of scientific trial molding.
6. The strict effectiveness of improvement plans for trial molding issues.
By addressing these six points effectively, the number of mold trials can be significantly reduced, lowering the production costs of injection molds.
Similarly, having scientific trial molding tools and an efficient trial molding management system will help companies complete the trial molding phase in the shortest time with the lowest cost and highest efficiency, allowing for early production and value creation.
