J. M. Voith Gmbh

Voith Sulzer Papiermaschinen Gesellschaft Mbh

Voith Patent Gmbh

Harald Aufrecht

Christian Schiel

Karl Steiner

Uwe Matuschczyk

Alfons Hochmüller

Werner Wachter

A press blanket in a pressing device intended for extracting water from a web in the press nip of a papermaking machine comprises an elastomeric matrix, in which the outer area, facing the web, is subjected to a thermal treatment in order to increase the wear-resistance. Although the elastomeric matrix thus consists of the same material throughout, the outer area, which is subjected to greater stresses, therefore exhibits increased wear-resistance. The press blanket is made in a single operation, by casting a hot-casting elastomeric matrix onto a cylindrical casting mold, while at the same time reinforcing threads are wound into the material. The press blanket is selectively thermally treated in order to achieve increased wear-resistance at the outer surface facing the web to a depth below the depth of grooves or bores on this outer surface.

Extended nip press blanket

A press jacket is formed of an elastomeric jacket material having two layers of reinforcement threads, namely an inner layer and an outer layer, embedded in it. The inner layer is formed of longitudinal threads which upon operation of the press device extend parallel to the axis of rotation of the press jacket. The outer layer is formed by a fabric layer or by circumferential threads which are wound helically and which, upon operation of the press device, extend approximately in the direction of travel of the press jacket. The reinforcement threads are surrounded by the layer of elastomeric material, which is produced homogeneously. The inner surface of the press jacket has longitudinal grooves which extend parallel to the longitudinal threads and have a depth of 0.1 to 0.2 mm. Various techniques of forming those grooves are described, including enlarging the longitudinal threads, pressing on the jacket which thereby deforms around the threads, forming voids or channels in the jacket rather than having threads therein or having the press jacket material deform around the threads due to application of heat or pressure to the press jacket.

Surface contoured press jacket for a shoe press

A press jacket is formed of an elastomeric jacket material having two layers of reinforcement threads, namely an inner layer and an outer layer, embedded in it. The inner layer is formed of longitudinal threads which upon operation of the press device extend parallel to the axis of rotation of the press jacket. The outer layer is formed by a fabric layer or by circumferential threads which are wound helically and which, upon operation of the press device, extend approximately in the direction of travel of the press jacket. The reinforcement threads are surrounded by the layer of elastomeric material, which is produced homogeneously. The inner surface of the press jacket has longitudinal grooves which extend parallel to the longitudinal threads and have a depth of 0.1 to 0.2 mm. Various techniques of forming those grooves are described, including enlarging the longitudinal threads, pressing on the jacket which thereby deforms around the threads, forming voids or channels (i.e. cavities) in the jacket rather than having threads therein or having the press jacket material deform around the threads due to application of heat or pressure to the press jacket.

Inner surface contoured press jacket by having cavities therein for a

A press blanket for a press device in a paper making machine, or the like, is formed of an elastomeric blanket material and fully embedded layers of reinforcement threads. The radially inner layer is formed of longitudinal threads which extend parallel to the axis of the press blanket. The radially outer layer is formed of circumferential threads which are wound in the direction of blanket motion and are wound generally helically. The threads are fully surrounded by the layer of homogeneous elastomeric material, that is formed from a single pouring. The circumferential threads have a diameter of at most 1/500 of the outside diameter of the fully rounded press blanket. In a unit area of the press blanket, the tensile strength of the circumferential threads is at least 40% greater than the tensile strength of the longitudinal threads. An apparatus for forming such a press blanket includes a rotatable pouring cylinder on which the longitudinal threads are supported, an elastomeric material pouring nozzle which moves longitudinally over the pouring cylinder and an unwinding device for delivering the circumferential threads in a helical manner and located just after the pouring nozzle above the pouring cylinder.

Apparatus for manufacturing a press blanket

Inner surface contoured press jacket for a shoe press

A press blanket for a press device in a paper making machine, or the like, is formed of an elastomeric blanket material and fully embedded layers of reinforcement threads. The radially inner layer is formed of longitudinal threads which extend parallel to the axis of the press blanket. The radially outer layer is formed of circumferential threads which are wound in the direction of blanket motion and are wound generally helically. The threads are fully surrounded by the layer of elastomeric material which is of homogeneous, that is formed from a single pouring. The circumferential threads have a diameter of at most 1/500 of the outside diameter of the fully rounded press blanket. In a unit area of the press blanket, the tensile strength of the circumferential threads is at least 40% greater than the tensile strength of the longitudinal threads. An apparatus for forming such a press blanket includes a rotatable pouring cylinder on which the longitudinal threads are supported, an elastomeric material pouring nozzle which moves longitudinally over the pouring cylinder and an unwinding device for delivering the circumferential threads in a helical manner and located just after the pouring nozzle above the pouring cylinder.

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Aalen, Germany

Harald Aufrecht