Life-science consumables: 12 defect types on purification columns, and presence and colour on reagent strips
Transparent plastics, membranes, gaskets and reagent zones are slow and inconsistent to check by eye. At about 17 μm with a 5 MP camera, 11 of 12 defect types on purification columns were detected.
Life-science consumables are mostly transparent or translucent plastics carrying membranes, gaskets and reagent zones. Defects are small and varied, and manual inspection is slow and differs between inspectors and shifts.
Case 1: purification columns
The customer listed 12 defect types: black specks in material, black specks on the cap, body scratches, cracked caps, broken caps, multiple rings, gasket flash, gasket contamination, missing gasket material, abnormal gaskets, missing membrane and uneven membrane rings. With a 5 MP colour camera at about 16.7 μm we compared a large ring light and a flat panel light:
- 11 of 12 types were imaged and detected; only body scratches did not appear under the tested conditions
- The flat panel gives sharp outlines but also sharp texture, so inspection regions must avoid textured areas
- The ring light produces glossy reflections and leaves more uninspectable area
- Cap specks are the smallest; about 20 μm resolution or finer is enough
Case 2: reagent strips
- Presence of the silver pad: checked by whether the background shows; all three lights work
- Presence and colour of the reagent zone: distinguished by hue (hue values about 27–31)
- Scratches: detected with flat panel and coaxial light; 0.06 mm defects at about 12 μm
- The inspection area has a height step, so two focus positions and two images are needed
Why automate
Consumables demand zero escapes and often require an image record of every part for traceability. Automated inspection judges by one consistent standard and archives results with the lot number.
