GB491779A - Improved pile fabrics and methods of making the same - Google Patents

Abstract

A pile fabric comprising a regenerated cellulose pile and a backing substantially non-reactive to formaldehyde, e.g. natural silk, is treated with formaldehyde or substances yielding formaldehyde, whereby the pile is rendered crush resistant. To the formaldehyde may be added a softening agent, preferably formamide; a stabilizer for the cellulose-formaldehyde reaction product; and a small percentage of an acid catalyst. The crush-resistant effects so produced are not affected by a high relative humidity. A suitable pile fabric may be made by interweaving a pile warp of regenerated cellulose with two ground fabrics, each comprising a warp and a filler of natural silk, the pile warp threads are then cut intermediate the two ground fabrics, so producing two pile fabrics. Velvet so produced is impregnated with formaldehyde and an acid or acid salt catalyst, dried at 200-250 DEG F. whilst the pile is brushed in alternate directions for 5-10 mins, followed if desired by a heating at the same or higher temperatures to complete the reaction. In one example a dyed velvet comprising a viscose pile and natural silk backing is stretched and treated with 24 per cent formaldehyde containing ,5 per cent ammonium chloride, dried at 200 DEG F. whilst the pile is brushed; the formaldehyde odour may be removed by treating with dilute ammonia or hot air; the fabric is advantageously rinsed in a weak tri-sodium phosphate bath. Suitable catalysts are ammonium chloride, bromide and iodide, potassium alum, hydrochloric acid, lactic acid, aminosulphoric acid, aluminium thiocyanate, aluminium chloride and ferric chloride. Suitable softening agents for use with the formaldehyde solution are sodium dodecyl sulphate, sulphonated oils, glycol monoesters, triethanolamine monostearic esters.