Abstract: An extrusion type coating apparatus having a coating head with a back edge end face and a doctor edge end face set close to a flexible support which is continuously run and with which a coating solution is applied to the flexible support. The inner edge of each of a pair of coating width regulating members made of metal and which are arranged in the slot of the coating head at respective ends thereof, are formed to have a radius of curvature of 0.5 mm or less, and the downstream edge of the end face of each coating width regulating member is continuous with the upstream edge of the doctor edge end face, while the upstream edge of the end face of each coating width regulating member is abutted against the inner wall of a back edge forming the coating head with the distance between the slot forming edge of the back edge end face and the upstream edge of the end face of the coating width regulating member set to half or less of the gap width of the slot.

Abstract: A method for removing dirt from a web in which a blow-off nozzle is provided extending over the width of a web. An edge of the nozzle at an end thereof is positioned close to one surface of the web. Air is blown through the nozzle while said web is being run past said nozzle so that deposits are removed from a surface of the web with the edge while the web is maintained in a floating state separated from the nozzle.

Abstract: An extrusion-type application device with which a liquid can be very rapidly applied to a carrier to form a thin layer thereon without causing streaking in the applied layer. The liquid is continuously expelled from the outside part of a slot to the surface of a flexible carrier continuously moving at a speed of 300 m/min or more along the surface of a back edge portion and the surface of a doctor edge portion so that the liquid is applied to the surface of the carrier. The surface of the doctor edge portion is curved, the inner longitudinal edge B of the surface of the back edge portion is located at the outlet of the slot so that the angle .theta..sub.1 between a tangent to the surface of the back edge portion at the inner longitudinal edge B and a tangent to the surface of the doctor edge portion at the outer longitudinal edge A of the surface of the doctor edge portion and the angle .theta..sub.

Abstract: A coating method and apparatus employing an extrusion-type coating head in which the probability of damaging the surface of the layer being formed on a support is remarkably decreased. Coating solution, such as a magnetic solution for forming a magnetic recording tape or the like, is supplied by a pump through a pipe line and then a filtering element to the extrusion-type coating head, which applies the coating solution directly or through a coating roll onto a running support. The filtering element, which is disposed at or near the coating solution supplying inlet of the extrusion-type coating head, has openings whose diameter is smaller than a coating clearance between a doctor edge of the extrusion-type coating head and the support or coating roll.

Abstract: An application device for applying a coating liquid to a moving web which forms an applied layer of uniform thickness and with smooth surface properties. The sides of a slotted portion of an extrusion-type application head are provided with sloped or stepped portions in regions adjacent liquid-free areas of the web. This prevents scratching of the web and accumulation of extraneous matter at the edge portions of the application head.

Abstract: An application device for applying a liquid such as a magnetic coating liquid to the surface of a continuously moving web in which the amount of chipping of the surface portions of the outlet portion of the coating head thereof, and hence the amount of streaking in the applied layer of liquid, are remarkably reduced. The outlet portion of the application head is made of a very hard alloy, preferably tungsten carbide, containing crystal grains of a carbide 5 .mu.m or less in mean diameter conjoined to each other by a metal, preferably cobalt in an amount of 12% or less.

Abstract: A coating material and apparatus in which the edge portions of the web being coated are supported off the edge portions of the coating head. In one embodiment, recesses are formed in the edge portions of the coating head, while in another embodiment a fluid is jetted towards the edge portions of the web. With the invention, scratching and the like of the edge portions of the web are eliminated, and the web is coating to a uniform thickness in the width direction thereof.

Abstract: 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.

Abstract: An application device for applying a coating liquid to a moving web which forms an applied layer of uniform thickness and with smooth surface properties. The sides of a slotted portion of an extrusion-type application head are provided with sloped or stepped portions in regions adjacent liquid-free areas of the web. This prevents scratching of the web and accumulation of extraneous matter at the edge portions of the application head.

Abstract: A coating method and an extrusion-type coating head in which turbulence at the junction between two flows of coating materials is prevented to provide multi-layer simultaneous coating over a wide range of coating rates and with a good coating quality. An intermediate block is sandwiched betwen a rear block defining a back edge and a front block defining a doctor edge. Two coating flows pass through slits formed on either side of the intermediate block, joining at the top end of the intermediate block and flowing together into a short slot extending between the end of the intermediate block and the outlet of the head.

Abstract: A curtain-type coating device including a coating head for applying a coating solution dropping in the form of a curtain from said coating head under force of gravity and which collides against the surface of a moving support to form a film layer on the support and a blade for guiding the curtain. A front edge of the blade is laid over a meeting line where the curtain meets the surface of the support in such a manner as to allow the passage of a film layer which has been formed on the support in advance.

Abstract: A coating method and an extrusion-type coating head in which turbulence at the junction between two flows of coating materials is prevented to provide multi-layer simultaneous coating over a wide range of coating rates and with a good coating quality. An intermediate block is sandwiched between a rear block defining a back edge and a front block defining a doctor edge. Two coating flows pass through slits formed on either side of the intermediate block, joining at the top end of the intermediate block and flowing together into a short slot extending between the end of the intermediate block and the outlet of the head.

Abstract: A method and apparatus for coating a magnetic liquid onto a moving substrate to form a magnetic recording medium having an improved product yield and reduced streaking. Coating liquid is fed to an extruder by a second pump, while excess coating liquid is extracted from the extruder and returned to a storage tank with a second pump. When the coating operation is to be stopped, the extruder is bypassed between the first and second pumps and a portion of the output from the first pump is returned directly to the storage tank so that the flow rates through both pumps are the same during coating and idling times.

Abstract: A method of simultaneously applying a plurality of liquids to a carrier to form respective layers thereon without causing a chromatic nonuniformity or longitudinal streaking in the layers, and to thus stably manufacture a magnetic recording medium of good magnetic recording properties. Liquids containing organic solvents are simultaneously applied to a continuously moving nonmagnetic carrier by an application head of the extrusion type so as to form respective plural layers on the carrier to manufacture a magnetic recording medium. The difference between the viscosities of the liquids present in the slots of the application head and which are to be applied to the carrier to form at least mutually adjacent ones of the layers is set at 50 cp or less, or the difference between the viscosities of the liquids present in the pockets of the application head or is set at 500 cp or less.

Abstract: An extrusion-type liquid application device having a simple construction but in which the width of the coating slit can easily be adjusted, even during a coating operation. Thick members are mounted on the doctor portion of a coating head extending perpendicular to the liquid discharge portion of the coating head. The thick members have acting portions at their upper ends abutting the surface of the doctor portions, central fulcrum portions, and opposite end portions provided with adjusting members. By adjusting the adjusting members, the slit width can be adjusted.

Abstract: A method and apparatus for coating a magnetic liquid onto a moving substrate to form a magnetic recording medium having an improved product yield and reduced streaking. Coating liquid is fed to an extruder by a second pump, while excess coating liquid is extracted from the extruder and returned to a storage tank with a second pump. When the coating operation is to be stopped, the extruder is bypassed between the first and second pumps and a portion of the output from the first pump is returned directly to the storage tank so that the flow rates through both pumps are the same during coating and idling times.

Abstract: A method for coating a running support with a coating solution, such as in the production of a magnetic recording medium, in which spreading of the coating solution into edge portions of the support not intended to be coated with the coating solution is prevented, hence providing a coating layer uniform in thickness and with good surface characteristics. Immediately before application of the coating solution to the support, a solvent is applied to regions of the support which are not to be coated with the coating solution and which are located on both sides of the coating region to be coated with the coating solution. In accordance with the invention, the solubility parameter of the solvent is made different from that of a solvent contained in the coating solution by at least 1.2 at a temperature of 25.degree. C.

Abstract: A method and apparatus for removing particles from a flexible sheet. The sheet is run over a rotating rod, rotating oppositely to the moment of the sheet. The rod is immersed on its lower side in a bath of solvent and excess solvent is removed from the bath and is filtered. Additionally, solvent may be applied to the sheet before it reaches the rotating rod or a negative pressure applied just upstream of the rod sucks away the particles.

Abstract: A method for simultaneously forming a plurality of organic-solvent-based magnetic layers on a moving support for the manufacture of a magnetic recording medium or the like. The surface tension of a solvent used to form the uppermost of the layers is made lower than that of the other layers. The most preferred range of the surface tension of the solvent which forms the uppermost layer is in a range of 0.1 to 3 dynes.

Abstract: An extrusion-type fluid applicator having a front wall located in upstream from a rear wall relative to a moving support (substrate) on which the applicator coats a liquid through a slot between the two walls. The front wall is convexly curved toward the support. The rear wall is retreated away from the convex surface of the front wall in a direction opposite the support. The slot is tapered to decrease the width thereof toward the support.