Sanitary Pants Quality Control
Quality problems in this category are rarely dramatic — they are a core that is five grams light, a cuff that does not seal, or a pack that fails a barcode scan. This page covers what to test, how to sample, and what to put in writing before production starts.
What to test
| Test | What it measures | Complaint it prevents |
|---|---|---|
| Absorption capacity | Millilitres of saline absorbed before leakage | "It does not hold enough" |
| Rewet under load | Liquid returning to the surface under pressure | "It feels wet" |
| Leakage under surge | Behaviour when liquid arrives faster than the core absorbs | Side and leg leaks |
| Core integrity after wetting | Whether the core breaks up or migrates | Bunching, uneven absorbency |
| Seal strength | Cuff and waistband bond strength | Cuffs detaching in use |
| Dimensional check | Measured size against the specification | Fit complaints, size grading drift |
Why the method matters
An absorbency figure without a method is not a specification. The same product can be reported at very different numbers depending on:
- Whether the liquid is delivered as a single dose or in several doses.
- Whether the sample is left to distribute between doses, and for how long.
- Whether load is applied during the test, and how much.
- Which liquid is used — saline, synthetic urine or water.
When you receive a test report, check that the method is stated and that it matches the way the product is actually worn. A single-dose test on a flat sample tells you very little about an overnight product.
The methods themselves — free swell, centrifuge retention, rewet under pressure — and what each one predicts in use are set out in absorbency testing.
Ask for the raw data, not the summary. A report that gives one number per SKU without the method, sample count and date cannot be used to resolve a dispute later.
Sampling and AQL
You cannot inspect every piece, so agree a sampling plan. AQL sampling to ISO 2859-1 is the usual basis: it defines how many units to pull from a lot, and how many defects are acceptable before the lot is rejected.
Three things must be written down, or the plan is unusable:
- The inspection level — general level II is common for consumer goods.
- The defect classification — critical (safety, contamination), major (leaks, missing layer, wrong size), minor (print misregistration).
- The acceptance numbers per class, agreed before production, not at inspection.
Pre-shipment checklist
- Carton count and carton markings match the purchase order.
- Barcode scans on a sample of finished packs, not on a proof.
- Size and weight checked against the approved specification sheet.
- Sealed approved sample pulled out and compared side by side.
- Packaging print position and colour against the approved proof.
- Any agreed special tests run on the production batch, not on the sample batch.
Documents
Ask for the specification sheet, the test report for the production batch, the inspection report, the packing list and any certificate your market requires. Keep the approved sealed sample — it is the only reference that settles "this is not what we agreed" without argument.
Factory questions
Before an order, ask questions whose answers can be checked:
- Which line will run this SKU, and what else runs on it?
- Which raw materials are used, and who supplies the pulp, SAP, nonwoven and film?
- What is the in-house test capability, and which tests go to a third party?
- What happens when a batch fails — rework, replacement or credit?
- Can you see the line (a live walk-through is a reasonable substitute for a visit)?
Supplier records on this site carry an evidence label; treat any listing as unverified until you hold these answers in writing. The material side is covered in the material guide.
Checks you can run yourself
Third-party inspection earns its cost on a first order, but it does not replace incoming checks on every shipment, and it will not catch a slow drift between batches. These five checks need a scale, a ruler, a jug and an hour. They target what inspection plans are weakest at: gradual specification change.
| Check | Method | Fails when |
|---|---|---|
| Piece weight | Ten pieces on a 0.01 g scale, against the approved sample | Outside the tolerance you set, for example three percent |
| Dimensions | Length and width flat, three pieces per size | Outside the size grading in the specification |
| Pour test | Measured saline poured at a fixed rate, timed | Surface stays wet, or liquid reaches the edge before the core takes it |
| Cuff recovery | Stretch the leg cuff and waistband, release, measure the return | Visible set or sag after repeated extension |
| Pack and barcode | Scan a finished pack, open one and reseal it | Scan fails, or the seal does not survive handling |
The pour test is the one worth standardising. Fix the volume, the rate, the orientation and the pass criterion, write them down, and repeat the same test on every shipment. The absolute result matters less than its consistency, because a change in the number is the earliest warning you will get. The methods it borrows from are in absorbency testing.
When a batch fails
A failed inspection is a commercial situation rather than a technical one, and it is usually decided long before the failure — by the acceptance criteria you agreed and by how much of the balance is still unpaid.
Work through it in this order:
- Confirm the finding against the agreed criteria. Name the test, the sample size, the measured value and the acceptance number. "Quality is poor" cannot be acted on by either side.
- Ask for the cause in one sentence. A substituted material, a machine setting and a bad raw-material lot are three different problems with three different fixes, and only the first is a supplier decision.
- Choose the remedy from a closed list — sort out, rework, replace the affected units, or a credit. Deciding which remedy applies to which defect class before the order turns the argument after a failure into a question of counting.
- Settle who pays freight before anything moves. On a rejected lot this is often larger than the value of the defective pieces.
Your leverage is the unpaid balance, and it evaporates the moment the container sails. That is why the final payment normally hangs on the inspection result rather than the sailing date, and why the acceptance criteria belong in the purchase order instead of an email thread. For the layer weights that cause most of the drift, see sanitary pants materials.
Frequently asked questions
- Is an ISO certificate enough to trust a factory?
No. A certificate shows a system was audited on a date; it does not tell you whether your SKU runs on a controlled line. Ask for the scope and the expiry date, then ask about the specific product.
- Who pays for third-party inspection?
Normally the buyer, and it is usually the cheapest insurance on a first order. Agree the sampling plan and acceptance criteria with the supplier beforehand so the result is not arguable.
- How many samples should be tested?
Enough that the result is meaningful for the batch — a single sample shows the product can pass, not that the batch will. Ask the laboratory or inspection body what their plan requires.
- What is the most common cause of rejected shipments?
Specification drift rather than outright defects: a lighter core, a thinner nonwoven or a substituted film that still looks correct. That is why the approved sealed sample and the written specification matter more than the inspection itself.
Latest industry notes
Short write-ups from our sourcing team on compliance, trade events and material changes that affect purchase orders.
- Trade Shows & Sourcing EventsWhat to Bring to a Supplier Meeting So the Follow-Up Moves2026-11-01
- Materials & QualitySanitary Pants Materials: Topsheet, Core, Backsheet and Waistband2026-10-15
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Set the acceptance criteria first
Send the specification and the market you are selling into. Agreeing the test methods and AQL levels before production is cheaper than resolving a rejected batch afterwards.