Testing Medium
Standardized testing strip contains multiple bands of different fiber types woven together to evaluate color transfer during wash or perspiration tests. This multi-fiber adjacent fabric is placed in contact with the dyed test specimen and subjected to mechanical action or moisture. The level of staining on each fiber strip reveals which materials are most vulnerable to color uptake from the dye.
It is a critical component of dye house quality control.
Fibre Types
The test strip consists of six or eight bands representing common commercial fibers. These bands usually include acetate, cotton, nylon, polyester, acrylic, and wool. When the test sample is washed, different dye types will bleed onto different bands of the multi-fiber adjacent fabric depending on their chemical affinity and the finish applied.
Nylon and cotton are particularly susceptible to staining because of their molecular structure.
Staining Grading
Color transfer is measured by comparing the stained band against a standardized grey scale for staining. A score of five indicates no change, while a score of one shows heavy staining. If a dyed fabric causes the nylon band on the multi-fiber adjacent fabric to drop below a score of four, the dye recipe is rejected.
This prevents color bleeding on multi-colored garments.
Quality Standard
Brands specify the required fastness ratings in their technical manuals. A mill must use the correct type of multi-fiber adjacent fabric to ensure their results match the brand’s laboratory. This ensures that test reports are comparable.
