How to Test and Validate a Thin-Wall Mold Before Shipping

The T0 trial is the first injection of plastic through a completed mold. Its primary purpose is verifying that all mechanical systems function correctly: mold opens and closes smoothly, hot runner heats up to target temperature with all zones operating, injection fills all cavities (even if not balanced), ejection system releases parts cleanly, and cooling circuits flow without blockage. T0 is conducted 2-4 days after mold assembly completion. The mold is mounted on an HWAMDA SPV5 machine matching the customer's model. Initial process parameters are set conservatively—slower injection speed, lower packing pressure, longer cooling time. Parts from the T0 trial are not expected to meet final quality specifications but should demonstrate that the mold produces recognizable containers in all cavities. HWAMDA documents the T0 trial with video, photographs of all parts, and an initial trial report noting any required modifications. The T0 trial typically reveals minor issues that are normal in mold development. This is why conducting trials before shipment is essential rather than discovering problems at the customer site.

The T2 trial is the final validation run simulating actual production conditions. The mold runs continuously for 500-2,000 cycles at target cycle time (for example, 4 seconds for 8-cavity yogurt cups on SPV5 400T). Process parameters are locked and recorded. Parts are collected at regular intervals for quality measurement to verify consistency over extended production. T2 validation criteria include: all cavities producing acceptable parts at target cycle time, cavity weight variation within ±2%, wall thickness within specification (±0.05mm), dimensional accuracy within drawing tolerances, visual quality free from defects (short shots, flash, sink marks, warping), and stable cycle-to-cycle consistency without parameter drift. A minimum of 50 sample parts are retained for customer evaluation. HWAMDA provides a complete T2 trial report including all process parameters, quality measurements, and production data. A minimum of 50 sample parts are retained and packaged for customer evaluation, with samples from the beginning, middle, and end of the T2 run demonstrating consistency throughout the production validation.

Customers should evaluate T2 samples against these criteria: Weight—measure 5+ parts per cavity, verify average within ±2% of target and cavity-to-cavity variation within ±2%. Wall thickness—measure at 4+ points per part (top, middle, bottom, base), verify within ±0.05mm of specification. Dimensions—verify rim diameter, height, and base diameter against drawing tolerances. Visual quality—no flow marks, burn marks, weld lines, or surface defects visible to naked eye. Functional testing includes: lid fit test (if applicable)—verify snap fit or press fit with target container, stacking test—verify containers stack properly without jamming or collapsing, drop test—filled containers dropped from 1 meter should not crack, and compression test—stacked column of 10+ containers should withstand specified load. For IML containers, verify label position accuracy (±0.5mm) and adhesion (tape peel test should not remove label). HWAMDA ships T2 samples to customers who cannot attend the trial in person. For IML containers, additional functional criteria include label position accuracy within 0.5mm, label adhesion strength, and decoration consistency across all cavities under production conditions.

Minor issues discovered during T0 or T1 trials are normal and expected—this is precisely why HWAMDA conducts 3 trials. Common T0 issues include unbalanced cavity fill (adjusted by hot runner manifold modification), inadequate venting (vents deepened or added), ejection marks (ejector pin positions adjusted), and cooling inadequacy (additional cooling circuits added). These are resolved between T0 and T1 at no additional cost. T1 issues may include wall thickness deviation (cavity machining adjustment), gate vestige quality (gate diameter or valve pin modification), and warpage (cooling optimization or gate relocation). These modifications are included in HWAMDA's standard mold price and are resolved before T2. If T2 trials reveal persistent issues that prevent meeting agreed specifications, HWAMDA works with the customer to identify root cause and implements corrective actions. Additional T3 or T4 trials are conducted at HWAMDA's cost until specifications are met or an agreed resolution is reached. HWAMDA's commitment to resolving all identified issues before shipment ensures customers receive production-ready molds that perform at target specifications from the first day of operation.