APPLICATION OF DURABLE-PRESS TREATMENT TO BLEACHED SOFTWOOD KRAFT HANDSHEETS

''Durable press'' is a textile-finishing chemical treatment that impar ts wrinkle resistance to fabrics by forming crosslinks between cellulo se molecules. This treatment was applied to bleached softwood kraft ha ndsheets in an effort to improve wet strength. The crosslinking agents used were maleic acid, citric acid, and 1,2,3,4-butanetetracarboxylic acid (BTCA). One catalyst (NaH2PO4) was particularly effective in pro moting the esterification reaction between handsheets and the crosslin king agents. This reaction was confirmed by the weight gain of the han dsheets, by Fourier-transform infrared spectroscopy, and by changes in sheet mechanical properties. Handsheet wet tensile strength improved significantly (as high as 63 % of the dry strength) when BTCA was used as a crosslinking agent. Treatment with BTCA or citric acid had no de trimental effect on dry tensile strength, and handsheet brightness inc reased following treatment. However, the treatment severely reduced fo ld strength.