Claims
- 1. A method for removing dirt from a web, comprising the steps of:
- providing a blow-off nozzle having a slit extending over the width of a web; setting an edge of said nozzle at an end thereof close to one surface of said web, said web being maintained separated from said edge by a distance of about several microns; and blowing air through said nozzle while said web is being moved past said nozzle at a predetermined speed so that deposits which are relatively large in size with respect to said distance are removed from a surface of said web with said edge while said web is maintained in a floating, non-contacting state separated from said nozzle;
- wherein, in said step of blowing air through said nozzle, a pressure of a stream of air produced by said nozzle is in a range of 0.01 to 5 kg/cm.sup.2 ; and
- further wherein an angle .alpha., which is formed between a surface forming a part of said edge on an upstream side in a direction of conveyance of said web and a plane perpendicular to said slit, is 5.degree.; and an angle .beta., which is formed between a surface forming an opposite part of said edge on a downstream side thereof and said plane, is 4.5.degree..
- 2. The method of claim 1, wherein said predetermined speed is in a range of 100 m/min to 300 m/min.
- 3. The method of claim 1, wherein said pressure of said stream of air produced by said nozzle is 5 kg/cm.sup.2.
- 4. The method of claim 1, wherein said edge is made of a cemented carbide material.
- 5. The method of claim 1, wherein said edge is made of a cemented ceramic material.
Priority Claims (1)
Number |
Date |
Country |
Kind |
63-130209 |
May 1988 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 07/358,767 filed May 20, 1989, now abandoned.
US Referenced Citations (7)
Continuations (1)
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Number |
Date |
Country |
Parent |
358767 |
May 1989 |
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