Durable press method

Claim 2

IN A METHOD OF TREATING CELLULOSE-CONTAINING MATERIAL TO IMPART A DURABLE PRESS THERETO: THE STEPS OF INTRODUCING MOISTURE FREE OF POLYMER-FORMING PRECONDENSATED INTO SAID MATERIAL BY SUBJECTING SAID MATERIAL TO STEAM AND RAISING THE TEMPERATURE OF THE ENVIRONMENT DUE TO THE STEAM, SUBJECTING THE MATERIAL TO FORMALDEHYDE AND SULPHUR-DIOXIDE VAPOR AGENTS AND TO STEAM IN AN ENVIRONMENT OF A TEMPERATURE HIGHER THAN THAT OF THE MATERIAL, SUBJECTING THE MATERIAL TO CIRCULATING AIR TO REMOVE MOISTURE AND SAID AGENTS THEREFROM, AND THEN HEATING THE MATERIAL TO A TEMPERATURE OF THE ORDER OF 250*F.

Claim 3

The method set forth in claim 1 wherein said first-stated step comprises injecting steam into a chamber containing said material to raise the temperature of the environment from that of the atmosphere to around 120*F, cutting off the steam and allowing the material to soak in the steam atmosphere for several minutes and the circulating outside air to drop the temperature of said environment to the starting value.

Claim 4

The method set forth in claim 1 wherein said last two steps include in the sequence named an exhaust-heating operation comprising circulating air through the material from the outside while concurrently heating the circulating air, and a closed-circuit heating operation wherein the atmosphere around the material is heated until the temperature of said material reaches a value of the order of 250* F.

Claim 5

The method set forth in claim 1 wherein said treating steps are carried out in a treating chamber including the spraying of water against the walls of said treating chamber after the temperature in said chamber reaches approximately 250* F. to cool said walls substantially to room temperature.

Claim 6

The method set forth in claim 3 wherein the temperature in said chamber is raised to a value from 120*F to 145*F by the injection of steam with the vapor agents and is then allowed to fall by at least 10*F after the steam is cut off, and wherein said temperature is raised to the order of 180*F at the end of said exhaust-heating step and is thereupon raised to at least 250*F.

Claim 7

In a method of treating fabric articles to impart thereto a durable press using a treating chamber and means for circulating air through said chamber via a blower in a sidE conduit including air exhaust and inlet ducts and a heat exchanger: the steps of providing fabric articles in said treating chamber having a predetermined moisture content free of polymer-forming precondensates, injecting sulphur dioxide and formaldehyde gases and steam into said chamber to cause said gases and steam to permeate said aricles in a rising temperature until said temperature reaches a value of from 120*F to 145*F, cutting off said steam injection to allow the temperature in said chamber to fall below said value, heating said chamber by said heat exchanger first by an exhaust circulation of air until the temperature in the chamber reaches the order of 180*F and then by a closed circulation of air until the temperature in said chamber reaches at least 250*F and then circulating outside air through said chamber and spraying the walls of said chamber with water to cool the articles in said chamber prior to the removal of the same.

Claim 8

In a method of treating fabric articles to impart thereto a durable press using a treating chamber and means for circulating air through said chamber via a blower in a sidE conduit including air exhaust and inlet ducts and a heat exchanger: the steps of providing fabric articles in said treating chamber having a predetermined moisture content free of polymer-forming precondensates, injecting sulphur dioxide and formaldehyde gases and steam into said chamber to cause said gases and steam to permeate said aricles in a rising temperature until said temperature reaches a value of from 120*F to 145*F, cutting off said steam injection to allow the temperature in said chamber to fall below said value, heating said chamber by said heat exchanger first by an exhaust circulation of air until the temperature in the chamber reaches the order of 180*F and then by a closed circulation of air until the temperature in said chamber reaches at least 250*F and then circulating outside air through said chamber and spraying the walls of said chamber with water to cool the articles in said chamber prior to the removal of the same.