Abstract:
A curtain coating apparatus includes a hopper with a slide plane on which the coating solution flows and a hopper lip from where the coating solution begins to freely fall down as a free falling curtain. The apparatus also includes at least a pair of outlets disposed in a position along the edge part of the free falling curtain and situated at a fixed distance down from the hopper lip. Auxiliary solutions are introduced from the width directions so as to maintain the curtain in the width direction.
Abstract:
A method for curtain coating various compositions at high speed onto a continuously moving receiving surface comprisesa) forming a composite layer of a plurality of coating compositions having density .rho. of total volumetric flow rate per unit width Q, forming a freely falling curtain from said composite layer, and impinging said freely falling curtain of height h against a continuously moving receiving surface such that the point of impingement has an application angle .theta.,b) providing said receiving surface with roughness, R.sub.z (DIN), between about 2 .mu.m and about 20 .mu.m,c) providing an electrostatic field at said impingement point whereby high coating speeds can be attained, andd) providing said coating composition forming the layer adjacent to said receiving surface with a viscosity measured at a shear rate of 10,000 s.sup.-1 sufficiently high that, when combined with said roughness R.sub.z, said curtain height h, said application angle .theta., said total volumetric flow rate per unit width Q, and said liquid density .rho., gives a value of specifying parameter .phi..sub.E that is greater than 1.
Abstract:
A method for curtain coating various compositions at high speed onto a continuously moving receiving surface comprisesa) forming a composite layer of a plurality of coating compositions having density .rho. of total volumetric flow rate per unit width Q, forming a freely falling curtain from said composite layer, and impinging said freely falling curtain of height h against a continuously moving receiving surface such that the point of impingement has an application angle .theta.,b) providing said receiving surface with roughness, R.sub.z (DIN), between about 2 .mu.m and about 20 .mu.m, andc) providing said coating composition forming the layer adjacent to said receiving surface with a viscosity measured at a shear rate of 10,000 s.sup.-1 sufficiently high that, when combined with said roughness R.sub.z, said curtain height h, said application angle .theta., said total volumetric flow rate per unit width Q, and said minimum liquid density .rho., gives a value of specifying parameter .phi..sub.0 that is greater than 1, and point whereby high coating speeds can be attained.
Abstract:
A system for coating a substrate with ultra-thin layers in stripes includes moving the substrate through a coating station and forming a composite layer including coating fluids and a carrier fluid. The composite layer flows at a rate that is sufficiently high to form a continuous flowing fluid bridge of composite layer to the substrate surface and to contact the substrate with the flowing composite layer to interpose the coating layers between the substrate and the carrier fluid. The carrier fluid is removed while leaving the coating fluid deposited on the substrate as a coating layer.
Abstract:
The method of coating a substrate with plurality of layers of coatings includes moving the substrate along a path through the coating station. A composite layer is formed of first and second coating fluids. The substrate contacts the flowing composite layer to interpose the first coating fluid between the substrate and the second coating fluid. The composite layer is doctored with a gas from a gas knife to remove some portion of the composite layer from the substrate.
Abstract:
A curtain coating method and apparatus using a rotatable or slidable coating plate and in which a coating liquid freely falls in the form of a thin film from a hopper. The thin film collides with a web continuously running and circumferentially turning around a backup roller to coat the web. The coating plate is rotated or slid to retract so that the freely falling coating liquid reaches the web so as to coat the web after the freely falling coating liquid flows along a checking plate which is doglegged in section and provided on a forward end of the coating plate, thereby coating the web with an even thickness at the start of coating operations.
Abstract:
The dielectric layer or layers in a ceramic capacitor having at least one buried electrode is deposited by a curtain coating process that includes obtaining a measure of the ceramic-paint-curtain thickness. A source of electromagnetic radiation, e.g. in the infrared range, is directed equally near the left and right edges of the curtain, and detectors at the opposite curtain surface side pick up the difference in the radiation transmissivity which is a measure of curtain thickness assymetry left to right. By adjusting the paint reservoir from which the curtain issues to make the difference zero and the curtain symmetrical, uniformity in paint coating thickness is achieved.
Abstract:
Tough heat- and corrosion-resistant films of polytetrafluoroethylene (PTFE) are baked onto the surfaces of sheet-type gaskets in a curtain coating process. The gasket to be coated is passed through a flow of liquid PTFE-resin containing composition, the gasket inverted end-for-end, the opposite side coated, then baked, to form a tough film.
Abstract:
A process for the multiple coating of objects or webs which are continuously moving past a coating point, using coating apparatus according to the curtain coating process. This process is carried out such that any number of comparatively high viscosity layers is embedded between an accelerating layer which is positioned below the layers and has a viscosity range of from 1 to 20 mPas and a layer thickness of from 2 to 30 .mu.m, and a spreading layer which is positioned above the comparatively high viscosity layers and has a viscosity range of from 1 to 10 mPas and a layer thickness of from 5 to 20 .mu.m. By the curtain coating process, coating rates of 400 m/min and more may be achieved with a good coating quality.
Abstract:
A process is taught in which a flexible, reinforcing travelling web may be uniformly, thinly transfer-coated, on both sides of the web simultaneously, with a low-viscosity liquid or mixture of monomers which may or may not wet the web, but does not wet the surface of a substrate on which the web and mixture are deposited. The liquid or mixture is first curtain-coated on an applicator curtain against which the web moves in controlled contact. An apparatus is provided for transfer-coating a travelling web with a low-viscosity liquid which is first curtain-coated on an applicator curtain.