Claims
- 1. An extrusion coating apparatus comprising:
- a coating head having a slit portion in a longitudinal direction of said coating head, said slit portion forming an opening on a surface portion of said coating head, said opening being confined between a front edge and a rear edge of said surface portion, and constituting a slit width, wherein said coating head extrudes a coating material from the bottom of said slit portion so that said coating material flows out of said opening after flowing through a gap of said slit portion;
- means for feeding a continuous web on said surface portion in a feeding direction from said front edge to said rear edge, said coating head applying said coating material along a coating width which is transverse to said feeding direction and parallel to said web, and
- a restricting member for restricting said slit width, said member having a width along a line perpendicular to said feeding direction and parallel to said longitudinal direction, and having a thickness along a line parallel to said feeding direction and perpendicular to said longitudinal direction, said thickness and said width structured to equalize distribution of said coating material along said coating width,
- wherein said width and said thickness satisfy the equation
- W=(S.times.X.times.L)/(k.times.T.times.100)
- wherein W is said width in millimeters, X is a corrected fluctuation of layer thickness in percent, L is a length of said slit in millimeters, k is a constant from 2 to 6, S is said slit width in micrometers, and T is said thickness in micrometers.
- 2. The apparatus of claim 1 wherein said restricting member is inserted into said slit from a side of said coating head, and an end of said restricting member is disposed outside said slit, bent, and thereby fixed by pinching a side plate.
- 3. The apparatus of claim 1 wherein said thickness of said restricting member is between 1% and 50% of said slit width.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3-263922 |
Oct 1991 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/942631, filed Sep. 9,1992, now abandoned.
US Referenced Citations (7)
Continuations (1)
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Number |
Date |
Country |
Parent |
942631 |
Sep 1992 |
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