Scouring

Definition and Overview

Scouring is a wet pretreatment carried out before dyeing and finishing. It washes away and removes oil, wax, dirt, and other impurities derived from the raw material, making it easier for chemicals and dyes to act evenly on the textile. It is not a process for creating the textile structure or pattern, but a processing step for bringing out the properties of the material.

In silk, the process of removing sericin that coats the raw silk is called degumming. In a broad sense, degumming is a type of scouring, but it is mainly the term used for silk. In cellulosic fibers such as cotton, removing natural waxes and oils is the main part of scouring.

Effects on Hand and Function

As impurities are reduced through scouring, water and dye can penetrate more easily, making it easier to prevent uneven dyeing. In cotton especially, absorbency is more likely to improve. However, bleaching to increase whiteness, singeing to burn off surface fuzz, and desizing to remove the sizing applied during weaving are separate processes with different purposes.

The conditions used for scouring also affect the material’s original hand. In silk, degumming makes it easier for luster, softness, and graceful drape to appear. On the other hand, processing conditions can change body, firmness, weight, and surface texture, so it is important to check the final result even for the same material name.

Main Applications

Scouring is carried out as a pre-dyeing treatment for apparel textiles made from natural fibers, whether yarn dyed or piece dyed. It is often involved in applications where absorbency, dye uniformity, and the hand against the skin are important, such as shirts, blouses, dresses, underwear, and bedding products.

For lightweight fabrics for spring and summer, it is often linked to the aim of improving absorbency and a light hand. In silk materials, it is related to products that make use of luster and drape, such as dresses, blouses, and scarves. However, seasonality and final use are not determined by scouring alone.

Selection and Handling Notes

When selecting a textile, check the final finishing, including not only whether it has been scoured but also the material, dyeing, softening treatment, and shrink-resist treatment. At the planning stage, it is reassuring to check hand, sheerness, color, and changes after washing using a swatch, and to perform testing and washing checks before mass production.

Even a scoured textile is not guaranteed to be free from shrinkage or skewing caused by washing. Natural fibers and blended materials change in dimensions depending on subsequent processing and washing conditions. Before sewing, if necessary, carry out hot water treatment or grain straightening, align the cutting direction, and set handling in line with the product washing instructions.

• Do not confuse scouring with bleaching or desizing; confirm the processing details in the specification sheet.
• In silk, the degree of degumming changes the hand and appearance.
• If product washing is planned, shrinkage testing is needed for the sewing thread and trims as well.

Differences from Similar Terms

Desizing is the process of removing the sizing applied to warp yarns to make weaving easier. Scouring mainly aims to remove oils, waxes, and other substances contained in the fibers themselves. In actual processing, both may be carried out in succession, but the targets and purposes are different.

Bleaching refers to a treatment that removes coloring components to make the textile appear whiter after scouring. Scouring alone does not necessarily make it white. Also, shrink-resist treatment is a process that suppresses dimensional changes caused by washing, and its purpose and effect are different from scouring.

Frequently Asked Questions