Ring-shaped coating apparatus

An apparatus for coating a cylinder with a solution, said apparatus comprising:

• (i) a coater including:
• a body having a circular hole through which the cylinder passes;
• a coating surface provided on a wall of the circular hole so as to surround an outer surface of the cylinder as the cylinder passes through the circular hole;
• a solution chamber provided in the body for storing the solution;
• a slit provided in the body for distributing the solution from the solution chamber to the coating surface;
• a feeding port provided on a periphery of the body;
• and
• a feeding conduit provided in the body for connecting the feeding port and the solution chamber so that the solution is fed from the feeding port to the solution chamber;
• and
• (ii) a conveyor for conveying the cylinder through the circular hole of the coater so that the outer surface of the cylinder is coated with the solution when the cylinder passes the coating surface provided on the wall of the circular hole;
• wherein the solution chamber has a height H2 of 5 mm to 50 mm, the slit has a slit gap distance HI, and a ratio of H2/H1 is 10 to 1000,
• wherein the solution chamber has an outlet port connected with the slit,
• wherein a height h between a center of the outlet port and a floor of the solution chamber, and a height H of the solution chamber are related such that:
• (1/3.times.H)<h<(2/3.times.H),
• and
• wherein the solution chamber has an inlet port connected with the feeding conduit, and the inlet port is positioned not higher than the outlet port.

An apparatus for coating a cylinder with a solution, said apparatus comprising:

• (i) a coater including:
• a body having a circular hole through which the cylinder passes;
• a coating surface provided on a wall of the circular hole so as to surround an outer surface of the cylinder as the cylinder passes through the circular hole;
• a solution chamber provided in the body for storing the solution;
• a slit provided in the body for distributing the solution from the solution chamber to the coating surface;
• a feeding port provided on a periphery of the body;
• and
• a feeding conduit provided in the body for connecting the feeding port and the solution chamber so that the solution is fed from the feeding port to the solution chamber;
• and
• (ii) a conveyor for conveying the cylinder through the circular hole of the coater so that the outer surface of the cylinder is coated with the solution when the cylinder passes the coating surface provided on the wall of the circular hole;
• wherein the solution chamber has a height H2 of 5 mm to 50 mm, the slit has a slit gap distance HI, and a ratio of H2/H1 is 10 to 1000, and
• wherein the coating surface is hopper-shaped, and the slit forms a circular discharging port on the hopper-shaped coating surface.

A coater for coating a cylinder with a coating solution, wherein an axis of the cylinder is vertically arranged and the cylinder is conveyed through the coater in an axial direction, said coater comprising:

• a coater body having a cylindrical hole through which the cylinder passes;
• a circumferential coating surface provided on a cylindrical wall of the cylindrical hole so as to surround an outer surface of the cylinder as the cylinder passes through the cylindrical hole;
• a ring-shaped solution chamber provided in the coater body for storing the coating solution;
• a feeding port provided on a periphery of the body;
• a feeding conduit provided in the body for connecting the feeding port and the ring-shaped solution chamber so that the coating solution is fed from the feeding port through the feeding conduit to the ring-shaped solution chamber;
• and
• a disc-shaped slit connecting the ring-shaped solution chamber and the circumferential coating surface so that the coating solution is distributed from the ring-shaped solution chamber to the circumferential coating surface,
• wherein the disc-shaped slit includes a circular outlet port through which the coating solution is discharged to form a coating solution layer on the circumferential coating surface so that the cylinder is coated with the coating solution layer when the cylinder passes the circumferential coating surface, and
• wherein the disc-shaped slit has a slit gap distance H1 between a ceiling of the disc-shaped slit and a floor of the disc-shaped slit, the ring-shaped solution chamber has a chamber height H2 of 5 mm to 50 mm between a ceiling of the ring-shaped solution chamber and the floor of the disc-shaped slit, and a ratio of H2/H1 is 10 to 1000.