Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
203 words
A method of manufacturing dimensionally stable, liquid-impermeable, flexible, elastic press bands, for the use in broad-nip wet presses of paper making machines, said press bands being provided on their surfaces with cavities or depressions suited for liquid drainage, comprising fixing a profiled film to the inner wall of a centrifugal tube so that said profiled film extends over substantially the entire inner wall of said tube, said profiled film being provided with cavities or depressions, rotating said tube and said profiled film, casting with a casting head a bubble-free, free-flowing mixture of a prepolymer onto an inner surface of the profiled film and curing the mixture, said casting head being movable in a longitudinal direction of said centrifugal tube so that said profiled film is filled with said free-flowing mixture and forms raised surface portions on the outer side of the finished press band which raised surface portions discharge liquid in a later pressing operation, and then grinding the cast press band while being still inside the centrifugal tube to a finished size on the inner side thereof; wherein said profiled film becomes an integral part of said press band to thereby form drainage depressions in the outer surface of said press band.
Claim 2
Independent Claim
203 words
A method of manufacturing dimensionally stable, liquid-impermeable, flexible, elastic press bands, for the use in broad-nip wet presses of paper making machines, said press bands being provided on their surfaces with cavities or depressions suited for liquid drainage, comprising fixing a profiled film to the inner wall of a centrifugal tube so that said profiled film extends over substantially the entire inner wall of said tube, said profiled film being provided with cavities or depressions, rotating said tube and said profiled film, casting with a casting head a bubble-free, free-flowing mixture of a prepolymer onto an inner surface of the profiled film and curing the mixture, said casting head being movable in a longitudinal direction of said centrifugal tube so that said profiled film is filled with said free-flowing mixture and forms raised surface portions on the outer side of the finished press band which raised surface portions discharge liquid in a later pressing operation, and then grinding the cast press band while being still inside the centrifugal tube to a finished size on the inner side thereof; wherein said profiled film becomes an integral part of said press band to thereby form drainage depressions in the outer surface of said press band.
Claim 3
Dependent Claim
61 words
A method as claimed by claim 1, wherein the profiled film on the inner wall of the centrifugal tube is placed into said tube sectionally in side-by-side relationship until the desired press band dimension is achieved, and then fixing said profiled film to the inner wall by means of clamping rings in the vicinity of the ends of the centrifugal tube.
Claim 4
Dependent Claim
37 words
A method as claimed by claim 1, wherein prior to casting the profiled film is treated with a release agent, in order to after the casting step facilitate removal of the press band from the centrifugal tube.
Claim 5
Dependent Claim
32 words
A method as claimed by claim 1, wherein prior to casting the surface of the profiled film lying opposite to the wall of the centrifugal tube is treated with an adhesion promotor.
Claim 6
Dependent Claim
33 words
A method as claimed by claim 1, wherein a centrifugal tube is used which is split into several sections which can be released from each other for removal of the cast press band.
Claim 7
Dependent Claim
21 words
A method as claimed by claim 1, wherein the application of the free-flowing prepolymer mixture is effected in a single operation.
Claim 8
Dependent Claim
27 words
A method as claimed in claim 1, wherein the casting of the free-flowing mixture is performed merely under the action of gravity on the rotating centrifugal tube.
Claim 9
Dependent Claim
28 words
A method as claimed in claim 1, wherein the casting of the free-flowing prepolymer mixture is performed in several steps to achieve different layers and degrees of hardness.
Claim 10
Dependent Claim
31 words
A method as claimed by claim 1, wherein a reinforcing band is placed directly on the inner surface of the profiled film resting on the inner wall of said centrifugal tube.
Claim 11
Dependent Claim
29 words
A method as claimed in claim 9, wherein spacer pieces are placed between the reinforcing band and the profiled film resting on the inner wall of the centrifugal tube.