BUYER GUIDE / INDUSTRIAL

Blister Tray Quality Inspection Standards and Acceptance Criteria

Tray quality is not a single pass-or-fail but a layered acceptance system: visual inspection catches surface defects, dimensional inspection verifies functional fit, functional inspection tests product interaction, and material-specific inspection covers ESD, food-contact or cleanliness where applicable. Each layer needs defined methods, limits and records that travel with the drawing revision.

Published and updated: 2026-08-25

Content author: Wenzhou Tonghou Plastic Products Co., Ltd.

04 / ENGINEERING NOTE

Inspection is layered, not a single gate

A tray that looks right can still fail functionally, and a dimensionally correct tray can still have surface or material issues.

Visual inspection catches flash, contamination, burn marks, warping and colour deviation before any measurement begins.
Dimensional inspection verifies that functional dimensions—the ones that position the product or fit the outer box—meet the agreed tolerance.
Functional inspection tests the real interaction: product fit, retention, removal, stacking and de-nesting with the actual product and box.
Material-specific inspection applies only when the project specifies ESD, food-contact or cleanliness requirements.

05 / ENGINEERING NOTE

Define methods, not just limits

A tolerance without a measurement method is unenforceable.

State the measurement method for each functional dimension: caliper, jig or fixture, and where the reading is taken.
Agree lighting and viewing distance for visual inspection, and keep the approved sample as the reference.
For ESD, define the electrode, voltage, conditioning and measurement locations—not just the resistance range.
For food-contact or cleanliness, reference the applicable standard or specification agreed for the project.

06 / ENGINEERING NOTE

From first article to repeat batches

Acceptance criteria only stay useful if they are applied consistently across batches.

The first article is inspected against all layers and the results recorded against the drawing revision.
Repeat batches re-check functional dimensions and any material-specific requirement at the agreed frequency, not every dimension every time.
Any drawing, material or process change triggers a new first-article cycle before production resumes.

Applications

First-article inspection for new tray projects
Production acceptance for repeat batches
Trays with ESD, food-contact or cleanliness requirements

Selection criteria

Visual: flash, warp, burn marks, contamination
Dimensional: functional dimensions within agreed tolerance
Functional: fit, retention, removal, stacking
Material-specific: ESD, contact or cleanliness as applicable

Pre-production validation

Define inspection layers, methods and acceptance limits before first-article. Record results against the drawing revision. For repeat batches, re-check functional dimensions and any material-specific requirement at the agreed frequency.

04 / DECISION MATRIX

Buyer decision table

Inspection layer	What it checks	Common method
Visual	Surface and appearance defects	Visual under agreed lighting, or against approved sample
Dimensional	Functional dimensions within tolerance	Calibrated measurement against drawing datum
Functional	Product fit, retention, stacking	Load actual product and box, test handling
Material-specific	ESD, food-contact, cleanliness	Project-defined test under agreed conditions

05 / BUYER QUESTIONS

Common buyer questions

01What is a functional dimension?

A dimension the tray must hold for the product to fit, the box to close or the packing line to run—not every dimension on the drawing.

02How much visual variation is acceptable?

Visual acceptance is defined against an approved sample under agreed lighting; the sample is kept as the production reference.

03Does every batch need ESD testing?

Only if the project specifies an ESD requirement. The test frequency is agreed per project and recorded with results.

04What triggers a full re-inspection?

Any change to the drawing, material, thickness or process should trigger a new first-article inspection cycle.

06 / SOURCE BOUNDARY

Official references

These sources define terminology, testing or acceptance methods. Citing a standard does not claim Tonghou certification and does not replace project-specific validation.

ISO — ISO 2859-1:2026 — Sampling procedures for inspection by attributes

Reference scope：Reference for lot-by-lot acceptance sampling. The drawing, defect classes, inspection level and limits still need buyer-supplier agreement.