GB455640A - Improvements in or relating to apparatus for manufacture of granule coated webs - Google Patents

Abstract

455,640. Granule-coated webs. ABBEY, A., 111, Hatton Garden, London.-(Carborundum Co. ; Niagara Falls, New York, U.S.A.) April 25, 1935, No. 12466. [Class 60] [See also Group XXXV] Apparatus for making granulecoated webs comprises a magnet system having oppositely arranged poles, means for supporting an adhesivecoated web in the field between the poles and means for supplying granules into the field adajacent to the coated surface of the web, so that the granules are magnetically oriented and projected on to the web. Paper or cloth P passes from a roll 2, Fig. 1, between printing rolls 4, 5 and thence in contact with idler rolls 7, 8, 9 to adhesive applying apparatus 11, 12, 13. The adhesive coating is smoothed by a vibrating brush 16 and the web is guided by idler rolls 18, 19, 20 into the field between electromagnets 22, 26. Granules are distributed from a hopper 35 on to an endless belt 41 which moves through the magnetic field beneath the web P. Upper and lower polepieces 24, 25 of the electromagnet 22 are positioned so that the web P is nearer the upper polepiece 24 so that the granules are propelled upwards on to the web. The upper and lower polepieces 28, 29 of electromagnet 26 are symmetrically and evenly spaced from the web P and are shaped to produce a distributed magnetic field which is relatively stronger at the part adjoining the field of magnet 22 and of gradually decreasing intensity at the part remote therefrom, to ensure that the granules remain vertically oriented as the web passes out of the magnetic field. The adhesive coating is preliminarily set by air from a blower 48 and the coated web then passes over an idler roll 49 and suction drums 51, 52 to a drying rack 55. In the modification shown in Fig. 3, granules supplied from a hopper 35 fall by gravity into the magnetic field from electromagnet 71 having polepieces 73, 74 similar to those of magnet 26, of Fig. 1, and are deflected towards the web by a member 78. The coated web is immediately passed around a roll 76 so that the orientation of the granules is not destroyed by gravitational attraction. If the granules are insufficiently magnetic they may be coated first with a lacquer or varnish and then with magnetic material such as iron or magnetic iron oxide.