"100% inspected" is a phrase that appears in a lot of supplier documentation and means different things at different factories. On a sanitary pad line it usually refers to a specific set of instrumented checks, and it is worth knowing exactly which ones.
What inline systems reliably catch
Modern pad lines carry camera and sensor arrays that monitor a defined list of parameters continuously. The reliable ones are:
- Presence and position of components. Wings, release paper, acquisition layer, core — present, and in the right place.
- Registration. Print position and pattern alignment within tolerance.
- Foreign material and contamination. Visual detection of discoloration or debris on the web.
- Dimensional checks. Width and length of the finished profile.
- Fold and seal position. On folded and wrapped products, whether the fold landed where it should.
These are geometric and visual properties, and cameras are good at them. Units failing these checks are ejected automatically, and the count is logged.
What inline systems do not catch
Everything that requires load, time or destruction to assess:
- Absorbency and retention. Requires a liquid test on a sample, off-line.
- Rewet under pressure. Same.
- Adhesive bond strength. Destructive, off-line.
- Seam strength on pants. Destructive, off-line.
- Material basis weight. Measured by sampling, not continuously on most lines.
- Odour and hand feel. Human assessment.
This is not a weakness in the systems; it is the boundary of what can be measured non-destructively at line speed. The mistake is treating an inline pass as evidence about the second list.
How the two layers fit together
A functioning quality system has three layers, and a claim of quality should be traceable to all three:
- Inline. Continuous, geometric, 100% coverage of the parameters listed above.
- Batch sampling. Destructive and laboratory tests on a defined sampling plan — absorbency, rewet, bond strength, basis weight.
- Incoming material. Checks on rolls and adhesives before they enter the line, including certificates and spot verification.
Most disputes arise when a buyer assumes layer one covers a property that only layer two can verify. A conversation about which layer covers what, held before the order, prevents most of them.
Questions worth asking about inspection
- Which parameters are instrumented, and which are visual-only?
- What is the sampling plan for destructive tests? Units per batch, and which tests.
- Are reject counts recorded per shift, and available on request? A factory that can produce this data has a working system.
- What happens to ejected units? Destroyed and recorded is the correct answer; reworked is not.
The quality control page describes how these three layers run in our plant, and the factory audit and evidence page covers what documentation a buyer can expect to receive.
