Auditing an Egg Carton Supplier: Where to Look

Certificates Do Not Show Consistency

A supplier can hold certification and still produce cartons that jam a line, because certification does not measure forming consistency.

The audit should focus on the four things that control the product: furnish, forming, moulds and inspection.

Each has a record that either exists or does not.

Furnish Control

Ask for the furnish composition and the lot records. A supplier using multiple sources without recording which lot went into which product cannot trace a problem.

Check the freeness measurement practice, if the plant measures it.

Ask how colour variation is managed between furnish lots.

Forming Consistency

Ask for the dwell, vacuum and moisture settings for the product, and whether they are recorded per run.

Look at the wall thickness records. A plant that measures thickness per shift has control; one that measures only at first article does not.

Ask about the cavity comparison practice.

Mould Maintenance

Ask for the mould history: runs, screen replacements, seal replacements and repairs.

Inspect the screens under light for blinding and deformation.

A mould without a history card is a mould whose condition is unknown.

Inspection

Look at the inspection standard and the records. Is there a visual standard with zones and limits?

Ask how many cartons are inspected per lot and what happens on a fail.

A plant that inspects without a written standard is inspecting by opinion.

Records That Prove a System

Exit moisture per lot, wall thickness per shift, cavity comparison, mould history and non-conformance records.

Ask for one month of each, for a product similar to yours.

A gap in one record is a finding; a gap in all of them is a system that does not exist.

The Audit Output

Findings with severity, a corrective action request with dates, and a re-audit date.

Audit the product you are buying, not a showroom sample.

Record what was seen, with photographs. An audit report without evidence is an impression.

Questions Buyers Ask

What should an egg carton supplier audit focus on?

Furnish control, forming consistency, mould maintenance and inspection, each with the records that show a real system.

Why do certificates not prove consistency?

Certification does not measure forming consistency, which is what determines whether cartons jam a filling line.

What records prove forming control?

Exit moisture per lot, wall thickness per shift and cavity comparisons, for a product similar to yours.

What does a mould history card show?

Runs, screen replacements, seal replacements and repairs. Without it, the mould condition is unknown.

What should an audit report contain?

Findings with severity, a corrective action request with dates, a re-audit date and photographic evidence.

Next Step

Send the product and the volume. You will receive an audit checklist with the records to request at each stage, in one reply.

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