Cutting – Processes – Cutting by direct application of fluent pressure to work
Reexamination Certificate
2000-04-06
2001-12-11
Rachuba, M. (Department: 3724)
Cutting
Processes
Cutting by direct application of fluent pressure to work
C083S098000, C083S177000
Reexamination Certificate
active
06327948
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to edge cutting of a paper web using a water jet.
BACKGROUND OF THE INVENTION
Previously known from Finnish patent 12457 is edge cutting by a water jet. From the Finnish publications 83106 and 88417 diagonal cutting of a paper web is known, i.e. in the first place longitudinal cut off by means of a water jet.
The construction as per patent 12457 can be applied when the paper web speed is slow and cutting carried out close to the wet end. Then the forces generated by cutting hardly have an impact on the web forward travel. Instead, cutting of dry paper has turned out to be difficult by growing web speeds. Especially, on coating the paper, the edge arrives at cutting only after coating, where the uneven edge margin with the coating border is removed. After coating, due to cutting, the advancing web is equal in quality up to the edge. It has been established that a high-speed water jet produces in the edge of a fast moving web braking powers preventing the use of a water jet cutter. The web proceeds indeterminately and the possibility of breaks in the line grows.
SUMMARY OF THE INVENTION
With a method and an apparatus according to this invention the above introduced problem has been settled. In accordance with a preferred embodiment of the invention, in a method of longitudinally cutting an edge of a moving paper web comprises: supporting the web from at least one side in a cutting position on a cutting top; directing air flow from a pipe positioned above the cutting top downwardly onto the web in a direction of travel of the web to press the web against the cutting top; arranging diagonally located guides on the surface of the cutting top steering the web towards the edge of the web; and cutting the web by using a water jet positioned downstream of the pipe in the direction of travel of the web.
In another preferred embodiment of the invention an apparatus for removal of an edge of a moving paper web comprises a water jet nozzle for generating a water jet for cutting through the web, the nozzle being arranged at a selected cutting point; a cutting top for supporting the web at the cutting point; diagonally arranged guides on a cutting top for steering the web towards the edge of the web; and a pipe positioned above the cutting top and directed downwardly onto the web and toward the web for directing a flow of air onto the web to press the web against the cutting top, said pipe being positioned upstream of the nozzle in the direction of travel of the web.
Advantages of the present invention can be considered that it is possible to generate enough counterforces in the web edge in order to compensate the inconvenient forces on the web by the water jet. Cutting can be carried out in a dried and even in a coated paper web moving even faster than 20 m/s.
The cut edge can be easily after-treated, since, after cutting, the position of edge is stable on utilizing the method and apparatus as per this invention.
REFERENCES:
patent: 3724045 (1973-04-01), Dryon
patent: 3976237 (1976-08-01), Bossons
patent: 4300421 (1981-11-01), Yano et al.
patent: 4505412 (1985-03-01), Reba
patent: 4527346 (1985-07-01), Schwartzott
patent: 4542842 (1985-09-01), Reba
patent: 4620466 (1986-11-01), Jumel et al.
patent: 4747329 (1988-05-01), Lukens, Jr.
patent: 4904344 (1990-02-01), Peiffer
patent: 4931140 (1990-06-01), Peltola et al.
patent: 5003729 (1991-04-01), Sherby
patent: 5036737 (1991-08-01), Glaser
patent: 5042351 (1991-08-01), Rosenthal
patent: 5083487 (1992-01-01), Croteau
patent: 5382404 (1995-01-01), Kogame
patent: 5571381 (1996-11-01), Vessari et al.
patent: 5699707 (1997-12-01), Campbell, Jr.
patent: 5762759 (1998-06-01), Wedel
patent: 5794500 (1998-08-01), Long et al.
patent: 6001219 (1999-12-01), Caspar
patent: 0 250 651 (1988-01-01), None
patent: 3222038 (1988-09-01), None
patent: WO94/05473 (1994-03-01), None
Larson & Taylor PLC
Rachuba M.
LandOfFree
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