Coating apparatus for applying coating material intermittently to substrate

An coating apparatus for applying a coating material to a surface of a substrate being moved continuously, said apparatus comprising:

• a coating die having a inlet port through which the coating material is introduced into the coating die, a discharge opening confronting with the substrate, through which the coating material is discharged onto the surface of the substrate, a supply passage defined in the coating die so as to communicate the inlet port with the discharge opening, a manifold chamber for temporarily storing the coating material supplied thereto and which is formed in a part of the supply passage, and a flexible sheet adapted to be displaceable away from the supply passage so that a draw-in chamber for absorbing the coating material is formed in the supply passage;
• an intermittent motion generating means having a ball screw mechanism which includes a ball nut and a ball screw for converting rotation of the ball nut into an intermittent reciprocating motion of the ball screw in the axial direction to cause the flexible sheet to be displaced;
• a servomotor for driving the ball nut for rotation;
• and
• a intermittent motion control means for controlling the servomotor so that the intermittent reciprocating motion to the ball screw causes the draw-in chamber to expand and contract periodically.