Patent GB-1311979-A (GB)
Title: Method and apparatus for producing a durable press in garments containing cellulose or cellulosic derivatives
IPC: D06M13/248
Filed: 1970-07-23
Abstract: 1311979 Method and apparatus for producing a durable press in cellulosic garments McGRAW-EDISON CO 23 July 1970 [1 Aug 1969] 35765/70 Heading DIP A method of producing a durable press in a fabric article containing cellulosic material characterized by placing the fabric in a closed chamber provided with formaldehyde gas, steam and sulphur dioxide. The heat of the steam causes the temperature in the chamber to rise and then cutting off the steam supply prior to supplying auxiliary heating to raise the chamber temp. to about 250F. The fabric articles are rid of residual odours by circulating air and/or steam through the chamber after it has reached 250F. In the chamber the amount of sulphur dioxide and formaldehyde gas are 0.1 to 2% and 2 to 10% respectively, by volume of the gases in the chamber at atmospheric pressure. The steam may be cut off, prior to heating the chamber to about 250F, which causes the temperature to fall a predetermined amount, to saturate the chambers atmosphere and produce greater condensation of moisture on the articles. The chamber may be heated indirectly through the chamber walls. The apparatus for carrying out the method comprises a double-walled box 10 and the heating means is either provided in the interwalled space of the box in thermal contact with the inner wall of the box or is located in the treating chamber in direct contact with the treating atmosphere. There is a receptacle 55 in the chamber for receiving a quantity of paraformaldehyde and means 56 for heating the receptacle to vaporise the paraformaldehyde. The apparatus for exposing the garments to moisture comprises means 67 for injecting steam into the chamber and manually settable means 95 for controlling the amount of steam injected in proportion to the weight of the cellulose in the garments being treated, also means 65 for introducing sulphur dioxide into the chamber. In a further embodiment for carrying out the method the apparatus comprises a chamber with an openable door 18 for receiving batches of prepressed articles, a port hole 71 in one portion of the chamber, a damper 77 for the port hole, an outlet vent 72 (with damper 78) opening in another portion of the chamber, a suction fan 51 having its intake connected with the outlet opening by way of the outlet damper and means for opening and closing the dampers. There is a spaced outer wall surrounding the chamber 12, air inlet means 75 for admitting outside air to the port hole and permitting a restricted continuous flow of outside air into the interwall space in the vicinity of the port hole and a vent fan 82 having its inlet connected to the interwall space for causing any leakage of gas around the port hole damper when it is closed to be drawn into the interwall space and exhausted. The apparatus also has pressure-relief means connecting the chamber to an outside vent and the chamber has a top wall that slants downwardly so that any condensate on the top wall drains down and does not drip onto the fabric articles being treated. There is also steam-jacketed heating means on one or more of the chamber walls, including means for leading steam into the jacket by a pipe extending horizontally across the chamber to serve as a rail 23 on which hangers bearing the fabric articles can be attached.