GB582006A - Improvements in or relating to the production of insulating materials - Google Patents

Abstract

582,006. Fibrous batting. BRITISH CELAN ESE, Ltd., (Celanese Corporation of America). Feb. 24, 1944, No. 3452. [Class 140] A self-supporting batting is prepared by forming a skin on both sides of a sheet or layer of interlaced and matted staple fibres of which a substantial proportion are thermoplastic, by rendering adhesive the thermoplastic fibres at or near the surfaces so that the fibres there stick to one another. The thermoplastic fibres are rendered adhesive either by the application of heat and pressure or by the application of a solvent or softening liquid or by both methods in conjunction. The thermoplastic fibres are preferably of cellulose acetate but other substances such as cellulose esters, mixed esters, cellulose ethers, synthetic linear polyamide condensation products, polymeric vinyl halides or vinyl esters of organic acids or their copolymers and polymerized methacrylic acid esters may be used. Non-thermoplastic fibres of cotton, silk, wool, regenerated cellulose, jute, hemp and like materials may be added but preferably constitute only 20 per cent. or less of the total fibre although up to 75 per cent. may be used. Local application of heat and pressure to the batting may be given for a quilted effect rendering small areas of the fibres adhesive throughout the thickness and uniting the two skins. The apparatus comprises a blower 12 which draws the fibres through an intake port 17 and discharges the separated fibres as a loose whirling mass within the chamber 16. The fibres are consolidated on a moving foraminous belt 18 by the suction of air drawn through perforations 21 in a chamber 20 which is connected to a vacuum pump. The belt is driven by toothed rollers 24, 26 mounted in adjustable shafts and connected to a suitable source of power, the speed of the belt determining the thickness of the batting. A doctor blade 32 directs the batting to a guide member 33 and to heated rolls 34, 35 which are surfaced with paper, fabric or plastic material to prevent sticking. Alternatively, belts or blankets may pass between the rolls and the batting. The time of contact with the heated rolls, their temperatures and the proportion of thermoplastic fibres determine the thickness of the skin which is formed. In another form of the apparatus, (not shown), a doffer beater opens up the staple fibres and throws them into a chamber and on to the moving conveyer belt through which air is drawn by suction. The belt passes the batting between two heated calendar rolls each of which carries an endless blanket passing over other idler rollers to prevent the batting sticking to the heated rolls. The batting then passes on to another conveyer belt and to an impact moulding device in which it is subjected to pressure from hot projections to give it a quilted form.