Method for manufacturing cylindrical member
The present invention has an object to provide a method for manufacturing a plurality of high quality cylindrical members. The method includes: vertically holding a mandrel so as to be coaxial with a central axis of an annular slit; and discharging a liquid coating through the slit to form a film of the coating on a surface of the mandrel while vertically moving up the mandrel. A circular cleaning blade is rotatably mounted around a lower holding shaft. The step includes the steps of: (1) forming a film of the coating up to a lower end of a coating region of the mandrel, and then stopping the discharge; and (2) moving up the lower holding shaft so that the cleaning blade passes through the annular slit to clean it, in this order. Then the cleaning blade is rotated to clean the cleaning blade.
1. A method for manufacturing a cylindrical member which comprises a mandrel and a coating formed on the peripheral surface thereof, the method comprising a step of:
vertically or substantially vertically holding a mandrel with an upper holding shaft and a lower holding shaft so as to be coaxial with a central axis of a ring-shaped coating head having an annular slit opening in an inner peripheral surface, and discharging a coating liquid through the annular slit while vertically or substantially vertically moving up the mandrel with respect to the ring-shaped coating head to form the coating on an outer peripheral surface of the mandrel,
wherein a circular cleaning blade is rotatably mounted around the lower holding shaft,
wherein the step includes the steps of:
(1) forming the coating of the coating liquid up to a lower end of a coating region on the outer peripheral surface of the mandrel, and then stopping discharge of the coating liquid through the annular slit;
(2) moving up the lower holding shaft with respect to the ring-shaped coating head so that the cleaning blade passes through the annular slit to clean the annular slit; and
(3) moving down the lower holding shaft with respect to the ring-shaped coating head so that the cleaning blade passes through the annular slit to clean the annular slit; in this order, and
wherein the method further comprises a step of rotating the cleaning blade around the lower holding shaft to clean the cleaning blade after at least one of the steps (2) and (3).
2. The method according to claim 1 , wherein in the step of cleaning the cleaning blade, the lower holding shaft is rotated with a collection container covering the cleaning blade.
3. The method according to claim 1 , wherein a plurality of cleaning blades are secured to the lower holding shaft.
4. The method according to claim 1 , wherein a diameter of the cleaning blade is larger than an inner diameter of the ring-shaped coating head.
5. The method according to claim 1 , wherein the cleaning blade is made of an elastic material.
6. The method according to claim 1 , wherein the cleaning blade contains one or two or more rubbers selected from the group consisting of urethane rubber, butyl rubber, fluororubber, and silicone rubber.
7. The method according to claim 1 , wherein the lower holding shaft is associated with a rotation axis of a rotary drive source and via a belt.
8. The method according to claim 1 , wherein the cylindrical member is an elastic roller used in an electrophotographic apparatus.
9. A method for manufacturing a cylindrical member which comprises a mandrel and a coating formed on a peripheral surface thereof, the method comprising a step of:
vertically or substantially vertically holding a mandrel with an upper holding shaft and a lower holding shaft so as to be coaxial with a central axis of a ring-shaped coating head having an annular slit opening in an inner peripheral surface, and discharging a coating liquid through the annular slit while vertically or substantially vertically moving up the mandrel with respect to the ring-shaped coating head to form a coating of the coating liquid on an outer peripheral surface of the mandrel,
wherein a circular cleaning blade is rotatably mounted around the lower holding shaft,
wherein the step includes the steps of:
(1) forming the coating of the coating liquid up to a lower end of a coating region on the outer peripheral surface of the mandrel, and then stopping discharge of the coating liquid through the annular slit; and
(2) moving up the lower holding shaft with respect to the ring-shaped coating head so that the cleaning blade passes through the annular slit to clean the annular slit; in this order, and
wherein the method further comprises a step of rotating the cleaning blade around the lower holding shaft to clean the cleaning blade after the step (2).