Yellowing Preventer

Yellowing mostly occurs when storing fabrics or garments in the warehouse. Plastic packaging material, like polybags contain BHT (butylated hydroxy toluene). This is an antioxidant that prevents degradation of the plastic. This BHT gets transferred to the fabric, also from carton boxes, a phenol (derivate) can be carried over to the textile. It can react with the nitrogen oxide (NOx) in the air and forms nitrobenzenes or quinone (or chinone), which is a yellow chemical substance. To avoid this yellowing preventers are applied on the fabric.

Heat-setting of wet fabric will also caused increased yellowing. Direct heated stenters produce NOx fumes by oxidation of nitrogen. These fumes are attacking the oils and the fibres during the setting operation, thereby causing yellowing. Moulding of fabrics (viz., women’s sports bra) leads to yellowing.