Fuji Photo Film Company, Limited

Kimiaki Miyamoto

Kiyoshi Kobayashi

Masahiro Morikawa

Kenji Nakajima

Yasushi Suga

Hideaki Usui

Toshimitsu Sasahara

In a coating apparatus where a coating composition is supplied from the lateral side of a manifold, a linear or curved taper along the width of the coating apparatus is given to the length a slit in the direction of flowing-out of the coating composition, so that the slit length is shorter in the counter-supply side than in the supply side of the manifold. The coating apparatus can make the distribution of the quantity of coating uniform in the case where the width of coating is large, or in the case where the quantity of flow per unit width in an individual layer is large.

Coating apparatus and machining method therefor

A coating method that is capable of rapid curtain coating without causing 'sagging' at high flow rates exceeding 4 cm.sup.3 /cm.sec. One or more layers of a coating solution are formed on a sliding surface, and a free falling curtain of the coating solution is allowed to impinge against a continuously running web. The web has a surface roughness of at least 0.3 .mu.m, the tip of the sliding surface forms an angle of 45.degree. to 120.degree. with respect to the horizontal, and the viscosity of the coating solution is adjusted to at least 90 cps for low shear rate, with the average for all layers formed being at least 80 cps.

Curtain coating method for eliminating sagging at high flow rates

A coating method by which the speed of coating can be improved remarkably regardless of the number of polar groups on the surface of a web and irrespective of the properties of material for the web. A coating solution flowing out of a liquid injector is applied to a web supported by a coating backup roller. A high frequency signal from a master oscillator is amplified and applied to a vibrator. Ultrasonic waves generated in the vibrator are guided by a horn to be radiated to the contact line between the coating solution and the web. With the invention it is possible to prevent a coating solution from being intermittently applied to a web, and it is also possible to increase the coating limit speed, for example, by 5 to 26%. In addition, lateral stair-stepped unevenness of thickness is not produced in the coating layer.

Coating method employing ultrasonic waves

A slide-hopper-type coating method in which the viscosity of the coating solution forming a free-falling curtain and the angle .alpha. which the front edge of the lip of the slide hopper forms with respect to the horizontal are selected with respect to the flow rate of the curtain in such a way that the line of contact between the curtain and the web is concave with respect to the direction in which the web travels. In addition, the angle .beta. which the extension of the curtain in the direction of its fall forms with respect to the direction of travel of the web at the point where the curtain is deposited on the web is preferably adjusted so that it is an obtuse angle not larger than 140.degree.. By satisfying these conditions, the coating method of the present invention is capable of extending the upper limit of coating speeds without causing 'sagging' in the range of high flow quantities of coating solution per unit length of curtain coat width.

Coating method

A curtain-type coating liquid application device having a slide hopper and an application start plate used to prevent an increase in the thickness of the initially applied portion of the liquid on a web to thereby make the initial coating portion flat and smooth. Liquid freely falling in the form of a thin curtain from the slide hopper is caused to collide against the web continuously moving around a backup roller so that the liquid is applied to the web. The application start plate is curved or bent and is turnable about a fulcrum located under the backup roller. The application start plate also has an upper end extending at an oblique angle to the direction of width of the curtain, or it may be provided with a curtain receiving part at the upper end of the plate.

Curtain coater with pivoted starting plate

A method and apparatus for coating a liquid coating composition to a moving web in which air entrained on the web is replaced by a gas having a higher solubility than air in the liquid coating composition. The moving web is exposed to the gas immediately before it arrives at a die through which the liquid coating composition is applied to the web. A vacuum system may be used to remove the air from the web prior to its exposure to the gas.

Growing community of inventors

Kanagawa, Japan

Kimiaki Miyamoto