Patent GB-811795-A (GB)
Title: Method and means for the automatic regulation of the continuous application of specified amounts of solids or liquids to a moving sheet of material
Inventor: JONES ERIC HARDING
IPC: D06B23/28
Filed: 1956-04-30
Abstract: 811,795. Coating webs. BRITISH COTTON INDUSTRY RESEARCH ASSOCIATION. July 29, 1957 [April 30, 1956], No. 13130/56. Class 140. A prescribed weight per unit length of a substance (e.g. a crease-resisting and flameproofing substance) is applied to a continuously moving sheet material (e.g. of textile) by supplying the substance to a reservoir at a rate predetermined by the speed of movement of the sheet material and the prescribed weight of substance to be applied thereto, and applying it, dissolved, dispersed, emulsified or in like liquid state to the sheet material, the reservoir forming part of a closed circulatory system of small capacity and any deviation from the prescribed rate of application being adapted to affect the rate of flow from said reservoir to another part of the circulatory system, the change in weight of liquid in the other part of the circulatory system thus produced being used to alter the concentration of the liquid to correct the rate of application of the substance. The change of weight may be measured directly or indirectly, from change of volume, depth of pressure. A pad box 11 of W-shape in end elevation has in each side a roller 20, which, together with rollers 21 and 22 serve to pass the sheet material through the pad box. Large diameter tubes lead coating material from the bottom of the pad box, through a pipe 13 having a terminal filter 24 to an overflow box 12 and so to control box 14 through pipe 15. The control box 14 lies on one arm 28 of a a balance 16 and has a pipe which conducts coating liquid along this arm to the pivot point and thence, through flexible pipe 32 to a circulating pump 17, throttle control 33 and back to the pad box. The other arm 29 of the balance has an adjustable weight and operates a mercury switch 30. Diluent from a floatcontrolled cistern 46 is led through a pipe 47, an on-off cock 48 and a self-cleaning filter 49 to a magnetic valve 50 controlled by mercury switch 30 and circuit 52, and thence through needle valve 51 to control box 14. Diluent is thus supplied to the box 14 whenever a deficiency occurs therein due to excessive takeup by the fabric 19. The stock liquid is fed to the system from a tank 34 through an on-off cock 36 and branch pipe 37 to a metering pump 39, the latter being driven through two variable speed gears 42 and 43 by a drive 44 taken from the main drive of the fabric rollers 22. The gears 42 and 43 can be preset to correspond to the amount of coating required and the width of material to be coated. Liquid passes from the metering pump 39 to control valve 40 and thence to control box 14 and so into the closed circulatory system. Another branch pipe 38 leads from the stock supply 34 directly to the pad box to prime the apparatus initially. Overflow from the pad box 11 to the control box 14, when the apparatus is stopped, is accommodated by the enlarged upper half of control box 14 and emergency overflow 25. A drain pipe 26 is placed in the bottom of the control box 14. The pipes depending into control box 14 have their ends so shaped and directed that reaction due to liquids issuing therefrom is minimized. Specification 654,178 is referred to.