In the case of gray fabric which has been kept for more than 2 months, strong scouring is necessary.

Japanese dyeing factories must use soft water for scouring. If water quality is poor, the scouring effect will also be poor. Thus, factories with poor water quality should use water softener.

Special care is necessary when scouring polyester/polyurethane blended fabric compared to pure polyester fabric.

In the case of scouring knitted fabric it is necessary to completely remove the thickener and oiling agent adhered to both the polyester and polyurethane. If the silicone oil adhered to the knitted cloth is not removed completely during relax-scouring, it will remain on the fiber and cause uneven dyeing. So, more dyeing factories choose DIADAVIN ESW, which does not damage the physical properties of polyurethane fiber.

Solvent scouring using fluorohydrocarbon and perchloroethylene can effectively remove silicone oil from the polyester/polyurethane conjugated knit fabric.

However, this is not environment-friendly, therefore, nonsolvent type scouring agents that make a superior scouring effect should be used.

Non-APEO types may be appropriate as scouring agents for woven fabric. The reason is that endocrine disruptors have been raised as a worldwide issue lately, and nonylphenol type scouring agents produce such chemical materials. The Environment Agency in Japan has identified a lot of items including nonylphenol as examples of chemical materials which Europeans refer to as endocrine disruptors.

For appropriate chelating agents that play an important role in scouring, Teikoku Chemical Industries Co., Ltd. (Japan) produces CLEWAT Bi series, environmentally-friendly chemical materials.

Bleaching is not necessary in the case of polyester/polyurethane blended fabric.

In case of knit fabric, it should be run through a few connected washing machines in order to maintain its structure.

Some factories are improving treatment effects by applying a tensionless rope washer.