The Treatment of Cotton with Formaldehyde in Calcium Chloride Solutions

Abstract

Cotton print cloth and broadcloth were cross-linked by soaking in aqueous solutions containing calcium chloride, hydrochloric acid, and formaldehyde. The calcium chloride concentration was varied to study the effect it would have on the rate at which combined formaldehyde content and wet and dry wrinkle recovery were obtained on the fabrics. Striking differences were observed between 10% and 50% calcium chloride. Thirty-five percent calcium chloride solutions were found to be best. A typical laboratory procedure consisted in soaking the fabric samples at room temperature (28°-30°C) in a solution containing 35% CaCl₂, 3.7% HCl, and 7.2% HCHO for the required length of time. Samples treated in this manner contained about 0.7% to 0.9% HCHO and had good wet and dry wrinkle recovery. The effect of time. temperature, and HCl and HCHO concentrations on reaction rates, combined HCHO content, and physical properties was also studied. Tearing strength and breaking strength retentions were in the range of 50-70%.