GB1446396A - Durable-press processing of cellulosic fibre-containing material - Google Patents

Abstract

1446396 Vapour-phase durable press process McGRAW-EDISON CO 14 March 1974 [14 March 1973] 11461/74 Headings D1L and D1P A durable press is imparted to cellulose fibre-containing material in web or garment form by a vapour-phase process in which the material is conveyed through successive stations for (1) moistening the material, (2) treating the moistened material with a mixture of formaldehyde and sulphur dioxide vapours and (3) drying and curing the material at about 250‹F. The temperature of the moistened material is preferably 20‹F lower than that of the formaldehyde and sulphur dioxide vapours to ensure condensation of the latter on the material. The moistening step may be effected by padding through a water bath or steaming in a compartment having water flowing down its walls. Steam is preferably also injected into the formaldehyde,'sulphur dioxide treatment compartment to maintain moisture. The drying and curing may be carried out in successive compartments, a pre-drying compartment containing drying cans or heated by an air flow and exhausting back into the chemical compartment, and a curing compartment heated by a closed circuit air flow. After curing, the material may be either washed and dried or steamed and dried. In the preferred embodiments, the stations are spaced along an elongate passageway through which the material if in web form is fed in a sinuous path over rollers, or if in garment form the garments are conveyed shoulder-to-shoulder, the various compartments being separated by air curtains, flap valves or soft rollers and the gas flow configuration being arranged such that there is a slight negative pressure at the entrance end. The preferred concentration in the chemical compartment is, by volume, 2-20% formaldehyde gas and 0.1-5% sulphur dioxide. Its temperature is preferably 20‹F above that of the steam compartment.