Key Precautions During a New Mold Trial
When a new mold is completed and ready for sampling, there is always strong pressure to see results as early as possible. Everyone hopes the mold trial will go smoothly, avoid unnecessary rework, and reduce delays in the project. However, the first mold trial should not be rushed. A careful and controlled trial process is essential to protect the mold, reduce risk, and obtain reliable evaluation results.
Before moving into normal injection molding conditions, the mold structure, machine settings, and trial sequence should all be checked step by step. A stable and disciplined trial process helps identify potential problems early and prevents avoidable damage to the mold or machine.
1. Check the Mold Carefully Before Starting Production
As soon as the mold is installed and opened for trial, the first step is to inspect the mold itself and confirm that all mechanisms move smoothly. This includes checking whether sliders, lifters, ejector systems, guide components, and other moving parts operate correctly without interference or abnormal resistance.
If any problem is found during this stage, the trial should be stopped immediately. Continuing operation when a problem already exists may lead to unnecessary damage, more serious mold issues, or wasted trial time. If no abnormal condition is found, the mold opening and closing actions should be repeated several times to confirm stable movement before proceeding to the next step.
2. Confirm Mold Clamping Force and Start with a Safe Short Shot
Before beginning injection, the mold clamping force should be confirmed carefully according to the actual mold and machine requirements. For the first molded sample, it is better not to fill the cavity completely at once. A safer method is to begin with about 80 percent of the full shot volume in order to check mold behavior under a more controlled condition.
If the initial short-shot result shows no abnormal issue, the molding process can then move gradually toward normal trial conditions. This allows the team to observe filling behavior, venting, parting line condition, and possible mismatch or interference before the mold is exposed to full production pressure.
3. Verify the Sample Before Further Pressure Testing
Once a normal trial sample is obtained, the molded part should be checked carefully to confirm whether it meets the expected standard in terms of filling condition, appearance, and general product quality. Only after confirming that the sample is acceptable should the next stage of high-pressure and low-pressure testing be carried out.
This step is important because it helps separate basic molding validation from later process analysis. If the product has obvious defects at the normal trial stage, it is better to solve those issues first before moving into more detailed pressure testing.
4. Perform High-Pressure and Low-Pressure Testing in a Controlled Sequence
During mold trial analysis, high-pressure and low-pressure conditions may be used to evaluate mold behavior and process stability. Under normal conditions, the mold can be analyzed at a higher pressure level of about 20 MPa and at a lower pressure level of about 10 MPa, depending on the actual product and mold situation.
However, all testing actions should begin from the lower-pressure and lower-load side first. Starting from a lower-pressure condition helps reduce risk and allows the operator to observe filling behavior more safely before increasing the load. A step-by-step trial sequence is always better than rushing directly into full pressure.
Why a Careful Mold Trial Process Matters
A new mold trial is not only about making the first sample quickly. It is also an important stage for checking mold function, confirming molding stability, identifying risk points, and protecting the mold from avoidable damage. A disciplined mold trial process can save time later by reducing repeated correction work and preventing unnecessary troubleshooting.
For this reason, mold trial work should always follow a controlled sequence: inspect the mold first, test the mechanisms carefully, begin with a safe short shot, confirm sample quality, and then continue with more detailed pressure analysis.
Mold Trial and Manufacturing Support from FITMOLD
FITMOLD supports mold development, mold trial evaluation, and production preparation for custom plastic part projects. Through practical mold checking, trial planning, and manufacturing review, we help customers reduce development risk and improve the transition from tooling completion to stable production.
If you are looking for a manufacturing partner for custom injection molds and plastic part production, FITMOLD can support your project from design review to tooling trial and production.
Contact us: sales@fitmold.com