Greige Fabric Storage Requirements and Preservation Standards
Unfinished greige fabric preservation demands humidity control between 50 and 65 percent relative humidity to prevent size retrogradation and oil oxidation.
Phenolic Yellowing
Chemical Discoloration
Yellow staining of white or pastel fabrics occurs when nitrogen oxides in the air react with sterically hindered phenols found in packaging materials. This specific type of phenolic yellowing usually appears as localized patches or streaks after garments have been stored in polybags or cardboard boxes for extended periods. The reaction is promoted by alkaline conditions on the fabric surface.
Source Identification
Antioxidants like butylated hydroxytoluene used in the manufacture of plastic films and adhesives are the primary culprits for this defect. Even if the fabric is processed perfectly, exposure to phenolic yellowing can happen at any point in the supply chain where the goods come into contact with low-quality packaging. The nitrogen oxides required for the reaction often originate from vehicle exhaust or gas-powered heaters in the warehouse.
Contamination can occur within the factory, during sea transit, or while the goods wait on retail shelves.
Test Standard
Laboratory methods such as the ISO 105-X18 test use impregnated papers to simulate the storage conditions that lead to this problem. Technicians assess the risk of phenolic yellowing by sandwiching a fabric sample between these papers and subjecting it to heat and pressure. A grey scale is then used to measure the intensity of the resulting yellow stain against a controlled standard.
Mitigation Technique
Neutralizing the pH of the fabric during the final rinse with a mild acid helps to inhibit the chemical reaction. Mills also specify the use of phenol-free packaging to eliminate the source of the problem at the start. These preventative measures are standard for high-end lingerie and sportswear brands that require pristine white finishes for their retail displays.