Pressure-type liquid coating applicator

Claim 1

Web coating apparatus for applying a thin coating of molten resinous composition to a web comprising: a carrier roll having a resilient peripheral surface for receiving a layer of coating material, and a metering roll having a hard non-resilient peripheral surface arranged in nip relationship therewith, said rolls having axes of rotation contained in a plane extending in angled relation with the vertical; means for rotating the carrier roll upwardly into said nip, and means for rotating said metering roll downwardly into said nip; liquid-applying means located along the underside of said nip comprising an upwardly-extending doctor blade in continuous engagement with a longitudinal portion of the periphery of said metering roll; dike means in spaced substantially-parallel coextensive relation with said doctor blade to extend in continuous uniform proximity with a longitudinal portion of said carrier roll; means for positioning said dike means to obtain any desired clearance thereof with said carrier roll; liquid-feeding manifold means supporting said doctor blade and dike means and extending in sealed relation with, and along, the edge portions thereof further away from said rolls; a pair of deckle devices received between opposite end portions of said doctor blade and said dike means, said devices being adjustable toward and away from each other to vary the width of application of coating material to a web; said devices, doctor blade, said dike means, and said manifold means forming an elongate, substantially-sealed, liquid-retaining region about areas of said rolls which are contiguous with said nip and face into said region; said manifold means comprising supply duct means extending in its longitudinal direction lengthwise of the doctor blade and dike means, the interior of said duct means being connected with said region by transverse passageway means at a plurality of points substantially along the entire length of said region and said duct means; jacket means substantially surrounding said duct means to define a heating chamber for circulating a heat exchange fluid therethrough; circulating means for supplying a heat exchange fluid to said jacket and circulating it therethrough at a desired temperature corresponding to a desired temperature and viscosity of a coating composition; means for heating and plasticizing a normally solid resinous coating material to a liquid heated condition; and pumping means for forwarding said material from said heating and plasticizing means to said liquid applying means.