摘要:
A coater to coat web includes an extrusion die, which has a die slot, for ejecting coating solution. A valve is disposed downstream from first and second conduits, for selectively feeding coating solution and bubble removing liquid to the extrusion die. A shifting mechanism moves the extrusion die between an offset position and a coating position. A controller causes the shifting mechanism to set the extrusion die in the offset position, feeds the bubble removing liquid to the extrusion die by setting the valve at the first conduit, feeds the coating solution by setting the valve at the second conduit, and causes the shifting mechanism to move the extrusion die to the coating position, to eject the coating solution from the extrusion die in the coating position. A bead of the coating solution is formed, for applying the coated layer to the web.
摘要:
A coating apparatus (10) has a coating head having a front edge surface (11) and a doctor edge surface (12). The coating head of the coating apparatus (10) is pressed onto a flexible support (100) laid and running between pass rollers (101) so that the support (100) can be coated with coating composition. The doctor edge surface (12) of the coating apparatus (10) is formed so that the variation rate, in the support width direction, of blade thickness in the support running direction of the doctor edge surface (12) does not exceed 5%.
摘要:
An extrusion coating head comprises an upstream side block (12) and a downstream side block (13) aligned in the conveying direction, and adjusting mechanism. The upstream and downstream side blocks (12, 13) respectively have edge surfaces (12a, 13a) on which the flexible support (1) is pressed. The upstream and downstream side blocks (12, 13) define therebetween a slit (15b) through which a coating composition can be extruded and applied onto the flexible support. The adjusting mechanism adjusts a length (t) of a perpendicular line which is drawn from an upstream end (A) of the edge surface of the downstream side block to a tangential line (L) of the edge surface of the downstream side block which is drawn from a downstream end of the edge surface of the upstream side block, to thereby adjust a distribution of a coating thickness on the flexible support in the width direction.
摘要:
A coating method utilizing an extrusion type coating apparatus having a back edge surface and a doctor edge surface for continuous extrusion of a coating fluid from a slot formed between the back edge surface and the doctor edge surface for applying the coating fluid onto a surface of a flexible support running continuously over both the back edge surface and the doctor edge surface. The doctor edge surface is located on a downstream side of the running of the support is so as to form a single inclined planar surface or a curved surface with a single curvature, so that when a point A represents a downstream end of the doctor edge and a point B represents a slot-top portion of the back edge surface, a line AB connecting the points A and B is achieved so that the doctor edge surface does not intersect. .theta..sub.1 represents an angle between a tangent to the back edge surface at the point B and the line AB, and .theta..sub.2 represents an angle between the line AB and the support stretched downstream from the point A. The angles .theta..sub.1 and .theta..sub. 2 satisfy the conditions: 150.degree.
摘要:
Coating apparatus for slide, extrusion or curtain coating of one or more liquids on a moving web in which the metering orifice for each fluid to be coated is filled with a porous plug.
摘要:
A metered bead extrusion coating apparatus for applying a coating fluid to a moving web includes a drawdown die having a beveled drawdown surface thereon, the angle between the drawdown surface and the axis of the extrusion slot being an obtuse angle.
摘要:
In an extrusion coating process of the flow-stretch type in which a ribbon of an aqueous gelatin coating composition is extruded through an elongated orifice onto a moving support and becomes stretched and attenuated in thickness between the orifice and support, at least one visco-elasticity enhancing agent is added to the coating composition in sufficient amount as to disproportionately increase the elasticity of the composition compared to its viscosity so as to render the composition stretchable at viscosities which are substantially reduced compared to what would otherwise be necessary for flow-stretch coatability.
摘要:
Providing a final doctor blade in a multiple blade coating apparatus having a surface dimension, in the direction of coated web movement, of at least five times that of the proceeding doctor blades.
摘要:
The present invention provides a coating method for coating one or more layers on a surface of a continuously moving belt-like substrate. The method includes a cleaning step of maintaining a cleanliness level of class 1000 or less near the substrate before a coating step. According to the present invention, any adhesion of extraneous material, dirt, dust and the like to a continuously moving web or coating layer surface can be prevented to reduce coating defects such as streak development.
摘要:
A method for slot extrusion coating a liquid composition at a coating temperature and a coating speed at or above 40 m/min, said liquid composition having a viscosity at said coating temperature of at least 500 mPa·s at a shear rate of 100 s−1, comprising the step of: (i) selecting said liquid composition for slot extrusion coating having a tan δ of less than 1000 measured by oscillatory dynamic viscosity measurements at 1 Hz, the coating temperature and a shear stress of 250 Pa under conditions in which there is effectively no variation in shear stress within said liquid composition during said measurement, said liquid composition being selected from liquid compositions each comprising at least one binder and a liquid carrier medium; and (ii) slot extrusion coating the composition via a slot onto a web support with a bead vacuum at the coating temperature and the coating speed.