Abstract 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.
A coating method for coating a continuously running flexible support with a coating solution by expelling said coating solution from a coating device onto said support so as to form a contact line between said coating solution and said support, wherein the improvement comprises continuously radiating ultrasonic waves from an ultrasonic wave generator separate from said coating device on or near a contact line between said support and said coating solution from a position rearward of said contact line so as to continuously vibrate an air layer accompanying said support immediately before contact of said support with said coating solution.
Claim 2
Dependent Claim
100 words
A coating method for coating a continuously running flexible support with a coating solution by expelling said coating solution from a coating device onto said support so as to form a contact line between said coating solution and said support, wherein the improvement comprises continuously radiating ultrasonic waves from an ultrasonic wave generator separate from said coating device on or near a contact line between said support and said coating solution from a position rearward of said contact line so as to continuously vibrate an air layer accompanying said support immediately before contact of said support with said coating solution.
Claim 3
Dependent Claim
21 words
The coating method of claim 1, wherein said ultrasonic waves have a frequency in a range of 10 to 120 KHz.
Claim 4
Dependent Claim
20 words
The coating method of claim 1, wherein said ultrasonic waves have a peak-to-peak amplitude of not less than 15 mmAq.
Claim 5
Dependent Claim
20 words
The coating method of claim 2, wherein said ultrasonic waves have a peak-to-peak amplitude of not less than 15 mmAq.
Claim 6
Dependent Claim
22 words
The coating method of claim 1, wherein an application point of said ultrasonic waves is within 5 cm of said contact line.
Claim 7
Dependent Claim
15 words
The coating method of claim 1, wherein said ultrasonic waves are applied through a horn.