Molded Pulp Quality Inspection: The Checks That Catch Bad Trays

Pulp parts vary naturally, so inspection needs measurable attributes: weight, dimensions at datum points, moisture, and crush strength — not just looks.

The Scenario: A defect that passed visual inspection

A buyer accepted 50,000 trays after a visual check. Six weeks later, product damage revealed the trays had thin flat spans that no one had weighed or measured.

Pain Points

• Visual inspection missed thin-wall sections;
• No moisture check meant trays shipped at 14% moisture, weakening them;
• The AQL plan checked only appearance.

The Solution: A measurable inspection plan

The buyer rebuilt the incoming inspection around measurable attributes:

1. Weight check Part weight correlates to wall thickness; deviation beyond ±5% flags thin parts.

2. Datum dimension check Critical dims measured at datum points, not averages.

3. Moisture and crush Moisture per TAPPI T 412 and crush per ASTM D642 at defined intervals.

The Result: Zero escapes in six months

The new plan caught two thin-wall batches before they shipped. The buyer added the checklist to the supplier quality agreement.