CA2161486A1 - Press blanket and method for producing the same - Google Patents
Press blanket and method for producing the sameInfo
- Publication number
- CA2161486A1 CA2161486A1 CA 2161486 CA2161486A CA2161486A1 CA 2161486 A1 CA2161486 A1 CA 2161486A1 CA 2161486 CA2161486 CA 2161486 CA 2161486 A CA2161486 A CA 2161486A CA 2161486 A1 CA2161486 A1 CA 2161486A1
- Authority
- CA
- Canada
- Prior art keywords
- press blanket
- threads
- press
- extending
- circumferential
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F3/00—Press section of machines for making continuous webs of paper
- D21F3/02—Wet presses
- D21F3/0209—Wet presses with extended press nip
- D21F3/0218—Shoe presses
- D21F3/0227—Belts or sleeves therefor
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F3/00—Press section of machines for making continuous webs of paper
- D21F3/02—Wet presses
- D21F3/0209—Wet presses with extended press nip
- D21F3/0218—Shoe presses
- D21F3/0227—Belts or sleeves therefor
- D21F3/0236—Belts or sleeves therefor manufacturing methods
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Paper (AREA)
- Printing Plates And Materials Therefor (AREA)
Abstract
There are provided a press blanket for a pressing device intended for extracting liquid from a web passing through a press nip of a papermaking machine, and a device for producing such a press blanket. In addition to the reinforcing threads extending in the axial direction and circumferential threads arranged thereon and extending in the circumferential direction of the press blanket, the press blanket comprises a continuous fabric layer or a bandage extending in the area between the circumferen-tial threads and grooves or blind holes starting at the surface of the press blanket. The continuous fabric layer acts to prevent the propagation of fissures that may form in operation due to the high pressing forces, preferably at the bottom of the grooves as a consequence of the high notch stresses prevailing at these points. This significantly improves both the service life of the press blanket and the operating safety. The fabric tape may be spirally wound into the compound simultaneously with the production process, by pouring the elastomeric material onto a preferably cylindrical casting mold.
Description
Backqround of the Invention The present invention relates to a press blanket for a pressing device intended for extracting liquid from a web of matted fibers passing through a press nip of a papermaking machine, comprising a layer of an elastomeric material, in which axial threads, extending transversely to the direction of movement of the web, are embedded as reinforcing threads.
The invention further relates to a method for producing a press blanket for a pressing device intended for extracting liquid from a web passing through a press nip of a papermaking machine, wherein a layer consisting of an elastomeric material is poured onto a casting mold which latter is provided with axial threads that serve as reinforcing threads and are mounted in axial direction along the circumference of the mold.
Related Prior Art U.S. patent 5,320,702 discloses a press blanket and a method for producing the same, wherein a layer consisting of an ela-stomeric material is poured onto a cylindrical casting mold, along whose circumference axial threads are mounted to extend in axial direction, while at the same time reinforcing threads extending along the circumferential direction of the casting mold are wound into the compound. One thus obtains a press blanket consistingofan elastomericmaterialwhich is reinforced by axial threads embedded in the compound and circumferential threads extending on top thereof.
21614~6 Press blankets of this type are normally provided with grooves or blind holes in their surfaces facing the web in order to enable the liquid extracted during the pressing process to be absorbed.
It has, however, been found that during operation the high pressing forces may in the course of time give rise to the formation of fissures, which due to the notch forces mainly start out from the grooves or blind holes. These fissures may enlarge over time and may end up by rendering the press blanket unserviceable.
U.S. patent 5,302,251 discloses a similar press blanket also comprising a layer of elastomeric material which is reinforced by axial and circumferential threads. Alternatively, the circumferential threads may be replaced by a fabric layer. The press blanket is designed to develop a wavy inner surface which allows for a better lubrication during service. To accomplish this, the axial threads and/or the fabric may be made from a resilient material, this leading to the development of a wavy inner surface during service underhigh pressure. However, also this design suffers from the formation of fissures during service life.
Therefore, it is an object of the present invention to provide a press blanket and a method for producing the same, which provides for extended service life. It is a further object of the invention to provide a press blanket and a method for producing the same, which develops only few fissures or reduces the propagation of fissures during service.
These and other objectives are achieved according to the invention by providing a continuous fabric layer, extending substantially in parallel to the surface of the press blanket, being embedded in the elastomeric material layer of a press blanket and extending over the circumferential threads wound around the axial threads. This fabric layer comprises at least one fabric tape preferably wound spirally around said axial threads and over said circumferential threads.
According to the invention, one succeeds with the aid of this continuous layer in preventing any fissures, beginning at the surface of the press blanket or at grooves or blind bores, from propagating beyond the fabric layer and in avoiding any further enlargement of the fissures and, thus, serious damage to the press blanket. As normally fissures will propagate in a direction perpendicular to the surface of the press blanket, their propagation is now limited bythe fabric layer because the notch forces are removed at this point by the fabric layer, the latter extending substantially in parallel to the surface.
Thus, the invention has the effect to considerably extend the service life of a press blanket. In addition, the strength of the press blanket is increased by the embedded fabric layer.
According to a preferred further improvement of the invention, the fabric tape extends substantially in the direction of movement of the web.
One thus arrives at greater strength of the press blanket and removal of the notch forces that act transversely to the blanket surface. In addition, this allows the press blanket to be produced in a simple and advantageous way~
The invention can be employed with particular advantage in cases where a press blanket according to the invention is provided with grooves or blind holes, as in these cases higher notch stresses must be expected.
According to a further embodiment of the invention, the fabric tape comprises approximately 60 to 90 % fibers extending in the circumferential direction, and approximately 40 to 10 %
fibers extending in the axial direction of the press blanket.
This has the effect to give the fabric tape increased tensile strength, especially in the circumferential direction~ which significantly increases the strength of the press blanket.
Preferably, approximately 25 % of the individual fibers of the fabric tape extend in axial direction~
The objects of the present invention are further achieved in connection with a method of the before-described kind by the fact that a fabric tape is wound into the compound in the circumferential direction of the casting mold while the ela-stomeric material is being poured onto the casting mold.
This enables the press blanket to be produced in a particularly simple and advantageous way and provides at the same time a particularly high strength, due to the good adhesion effect between the fabric tape and the elastomeric material.
The invention further relates to a method for producing a press blanket for a pressing device intended for extracting liquid from a web passing through a press nip of a papermaking machine, wherein a layer consisting of an elastomeric material is poured onto a casting mold which latter is provided with axial threads that serve as reinforcing threads and are mounted in axial direction along the circumference of the mold.
Related Prior Art U.S. patent 5,320,702 discloses a press blanket and a method for producing the same, wherein a layer consisting of an ela-stomeric material is poured onto a cylindrical casting mold, along whose circumference axial threads are mounted to extend in axial direction, while at the same time reinforcing threads extending along the circumferential direction of the casting mold are wound into the compound. One thus obtains a press blanket consistingofan elastomericmaterialwhich is reinforced by axial threads embedded in the compound and circumferential threads extending on top thereof.
21614~6 Press blankets of this type are normally provided with grooves or blind holes in their surfaces facing the web in order to enable the liquid extracted during the pressing process to be absorbed.
It has, however, been found that during operation the high pressing forces may in the course of time give rise to the formation of fissures, which due to the notch forces mainly start out from the grooves or blind holes. These fissures may enlarge over time and may end up by rendering the press blanket unserviceable.
U.S. patent 5,302,251 discloses a similar press blanket also comprising a layer of elastomeric material which is reinforced by axial and circumferential threads. Alternatively, the circumferential threads may be replaced by a fabric layer. The press blanket is designed to develop a wavy inner surface which allows for a better lubrication during service. To accomplish this, the axial threads and/or the fabric may be made from a resilient material, this leading to the development of a wavy inner surface during service underhigh pressure. However, also this design suffers from the formation of fissures during service life.
Therefore, it is an object of the present invention to provide a press blanket and a method for producing the same, which provides for extended service life. It is a further object of the invention to provide a press blanket and a method for producing the same, which develops only few fissures or reduces the propagation of fissures during service.
These and other objectives are achieved according to the invention by providing a continuous fabric layer, extending substantially in parallel to the surface of the press blanket, being embedded in the elastomeric material layer of a press blanket and extending over the circumferential threads wound around the axial threads. This fabric layer comprises at least one fabric tape preferably wound spirally around said axial threads and over said circumferential threads.
According to the invention, one succeeds with the aid of this continuous layer in preventing any fissures, beginning at the surface of the press blanket or at grooves or blind bores, from propagating beyond the fabric layer and in avoiding any further enlargement of the fissures and, thus, serious damage to the press blanket. As normally fissures will propagate in a direction perpendicular to the surface of the press blanket, their propagation is now limited bythe fabric layer because the notch forces are removed at this point by the fabric layer, the latter extending substantially in parallel to the surface.
Thus, the invention has the effect to considerably extend the service life of a press blanket. In addition, the strength of the press blanket is increased by the embedded fabric layer.
According to a preferred further improvement of the invention, the fabric tape extends substantially in the direction of movement of the web.
One thus arrives at greater strength of the press blanket and removal of the notch forces that act transversely to the blanket surface. In addition, this allows the press blanket to be produced in a simple and advantageous way~
The invention can be employed with particular advantage in cases where a press blanket according to the invention is provided with grooves or blind holes, as in these cases higher notch stresses must be expected.
According to a further embodiment of the invention, the fabric tape comprises approximately 60 to 90 % fibers extending in the circumferential direction, and approximately 40 to 10 %
fibers extending in the axial direction of the press blanket.
This has the effect to give the fabric tape increased tensile strength, especially in the circumferential direction~ which significantly increases the strength of the press blanket.
Preferably, approximately 25 % of the individual fibers of the fabric tape extend in axial direction~
The objects of the present invention are further achieved in connection with a method of the before-described kind by the fact that a fabric tape is wound into the compound in the circumferential direction of the casting mold while the ela-stomeric material is being poured onto the casting mold.
This enables the press blanket to be produced in a particularly simple and advantageous way and provides at the same time a particularly high strength, due to the good adhesion effect between the fabric tape and the elastomeric material.
The fabric tape, just as the reinforcing threads, may in this case consist of a high-strength material, for example of aramide fibers.
In case that no reinforcing threads extending in the circumferen-tial direction are used, the fabric tape, preferably, should be wound at least in two layers so as to provide a continuous double fabric layer offering a sufficiently high strength~
In addition, it is of course also possible to wind circumferen-tial threads spirally over the axialthreads in circumferential direction, while at the same time the fabric tape is spirally wound over such circumferential threads.
During casting the casting mold, which preferably takes the form of a casting cylinder, is rotated about is center axis while simultaneously the elastomeric material is introduced, which latter preferably is applied on the casting mold from the top, through a casting nozzle.
It is understood that the features mentioned above and those yet to be explained below can be used not only in the respective combinations indicated, but also in other combinations or in isolation, without leaving the scope of the present invention.
Brief Descri~tion of the Drawinqs Further features and advantages will become apparent from the following description of certain preferred embodiments of the invention. In the drawings:
Fig. 1 shows a cross-sectional view of a detail of a first embodiment of the press blanket according to the invention;
ig. 2 shows a modification of the embodiment according to Fig. 1, in reduced scale;
Fig. 3 shows an enlarged cross-sectional view of a detail of the fabric tape according to Fig. 1;
ig. 4 shows a simplified representation of a device for producing apress blanketaccording to the invention;
and ig. 5 shows a simplified representation of a pressing device of a press blanket according to the invention, in the area of the press nip.
Description of Preferred Embodiment In Fig. 1, a press blanket according to the invention is generally indicated by reference numeral 10.
Fig. 5 is a diagrammatic representation of the conditions existing at a press nip 50 of a shoe press of conventional design, where the press blanket 10 revolves between a lower press shoe 54 and a back-up roll 52, a web 56, being constituted by a pulp sheet containing water, being guided between the back-up roll 52 and a felt 58 that runs above the press blanket 10.
Due to a high pressing force prevailing in the press nip 50, the water is extracted from the web 56 in the press nip 50 and is absorbed by the felt 58 and in part by grooves or blind holes provided in the press blanket 10.
The press blanket 10 takes the form of an endless, hose-shaped tape comprisingan elastomeric matrix16, preferably consisting of polyurethane. The matrix 16 is reinforced by axial threads 22 extending in the axial direction of the press blanket 10 and transversely to the direction of movement 60 of the web 56, as shown in Fig. 5. on the axial threads 22, there are provided equally spaced circumferential threads 20 extending in the circumferential direction of the hose-like press blanket, i.e. substantially in the direction of movement 60 of the web (Fig. 1). The circumferential threads 20 are spiral]y wound over the axial threads 22, as will be described in more detail further below, with reference to Fig. 4.
The axial threads 22 and the circumferential threads 20 form together a thread structure as described for example in US 5,320,702.
A plurality of grooves 12, extending likewise in the circumferen-tial direction of the press blanket, i.e. in parallel to the direction of movement 60 of the web, open toward the surface 14 of the press blanket 10 that faces the web 56. The grooves 12, which are equally spaced one to the other, serve for absorbing the liquid being extracted from the web 56 as it passes the nip 50. In the illustration of Fig. 1, the grooves 12 exhibit a U-shaped cross-section 12, although a different, for example a rectangular cross-section would be possible as well.
Between the grooves 12 and the circumferential threads 20, there is arranged a continuous fabric layer 18, extending in parallel to the surface 14 of the press blanket 10 and being formed by a fabric tape 25, which is spirally wound into the compound in the circumferential direction of the press blanket 10, above the circumferential threads 20.
The fabric tape 25 is wound in partially overlapping arrangement so that single-layer areas 26 alternate with double-layer areas 24 where the fabric tape overlies part of the neighboring layer.
When the press blanket 10 according to the invention is used in a pressing device for extracting water from a web 56 in a press nip 50 of a papermaking machine, the high forces acting in the nip may in the course of time lead to the formation of fissures which, due to the notch stresses caused by the grooves 12, will in most of the cases propagate from the grooves 12 in the radial direction of the press blanket 10, i.e. in a direction toward the axial threads22. During further operation of the press blanket 10 additional such fissures may be formed, and the fissures may enlarge. But due to the presence of the continuous fabric layer 18 such fissures are prevented from propagating beyond the layer 18, which means that any further enlargement of the fissures and, thus, possible leakage and unserviceability of the press blanket 10 will be avoided. ~11 in all, the service life and operating safety of the press blanket 10 is, thus, significantly improved.
Preferably, the axial threads 20 and the circumferential threads 22 consist of high-strength plastic fibers, for example aramide fibers. The fabric tape 18 may consist of a textile fabric, for example a non-woven fabric, and may be less strong than the reinforcing threads 20, 22, the dimensional stability of the press blanket 10 being already ensured by the reinforcing threads 20, 22.
Given the fact that the fabric tape 18 extends in the circum-ferential direction of the press blanket 10, i.e. in the direction of movement 60 of the web, it is sometimes even possible to do without the circumferentially extending rein-forcing threads 20, as indicated in Fig. 2. The press blanket illustrated in Fig. 2 is designated generally by reference numeral 30. Those parts that correspond to Fig~ 1 are indicated by the same reference numerals as in Fig~ 1. Modified elements are also designated by the same reference numerals, followed only by an apostrophe. The fabric layer 18' consists again of a fabric tape 25', that is spirally wound -in the circumferential direction of the press blanket 10 - into the press blanket area between the grooves 12 and the axial threads 22. In order to arrive at a higher strength, it is ensured, by having the fabric tape 25' fully overlap during winding, that a continuous double fabric layer 18' is obtained so that each area 24' of the fabric tape 25' overlaps an underlying area 26' of the fabric tape.
In order to further increase the strength of the press blanket 10, the fabric tape 25' may also consist of a high-strength material, for example of glass fibers or aramide fibers.
The structure of the fabric tape 18 is illustrated schematically in Fig. 3. It is apparent that the fabric tape 18 is formed predominantly of threads 19 that extend in the longitudinal direction of the fabric tape and that are held together by one or more threads 21 extending transversely thereto. Preferably, approximately 75 % of the threads of the fabric tape are oriented in the circumferential direction, while 25 % of the threads are oriented in axial direction.
A device for producing a press blanket according to the invention is illustrated in Fig. 4 and is indicated generally by reference numeral 40. The device comprises a cylindrical casting mold 42, between the two end faces of which the axial threads are mounted in mutually parallel arrangement at a predetermined distance from the surface. Polyurethane is fed via a line 48 and applied from the top through a casting nozzle 49, while the casting mold 42 is simultaneously rotated about its center axis 44, in the direction indicated by arrow 46, and the casting nozzle 49 is advanced by means of a carriage in a direction parallel to the center axis 44 so that a cylindrical circumferen-tial surface will gradually form during the continuous castingoperation. During this process, the compound passes through the axial threads 22 until it comes to deposit on the casting mold 42, thereby forming the elastomeric matrix 16 of the press blanket 10.
At the same time, the circumferential threads 20 and, on top of the latter, the fabric tape 18 are spirally wound into the compound, which provides a particularly good adhesion effect between the matrix and the reinforcing threads 20, 22 and the fabric tape 18, respectively.
If a press blanket according to Fig. 2 is to be produced, no circumferential threads 20 are used so that only the fabric tape is wound into the compound, the degree of overlapping being preferably selected in this case - as mentioned before -in such a way that a double fabric layer is obtained.
In case that no reinforcing threads extending in the circumferen-tial direction are used, the fabric tape, preferably, should be wound at least in two layers so as to provide a continuous double fabric layer offering a sufficiently high strength~
In addition, it is of course also possible to wind circumferen-tial threads spirally over the axialthreads in circumferential direction, while at the same time the fabric tape is spirally wound over such circumferential threads.
During casting the casting mold, which preferably takes the form of a casting cylinder, is rotated about is center axis while simultaneously the elastomeric material is introduced, which latter preferably is applied on the casting mold from the top, through a casting nozzle.
It is understood that the features mentioned above and those yet to be explained below can be used not only in the respective combinations indicated, but also in other combinations or in isolation, without leaving the scope of the present invention.
Brief Descri~tion of the Drawinqs Further features and advantages will become apparent from the following description of certain preferred embodiments of the invention. In the drawings:
Fig. 1 shows a cross-sectional view of a detail of a first embodiment of the press blanket according to the invention;
ig. 2 shows a modification of the embodiment according to Fig. 1, in reduced scale;
Fig. 3 shows an enlarged cross-sectional view of a detail of the fabric tape according to Fig. 1;
ig. 4 shows a simplified representation of a device for producing apress blanketaccording to the invention;
and ig. 5 shows a simplified representation of a pressing device of a press blanket according to the invention, in the area of the press nip.
Description of Preferred Embodiment In Fig. 1, a press blanket according to the invention is generally indicated by reference numeral 10.
Fig. 5 is a diagrammatic representation of the conditions existing at a press nip 50 of a shoe press of conventional design, where the press blanket 10 revolves between a lower press shoe 54 and a back-up roll 52, a web 56, being constituted by a pulp sheet containing water, being guided between the back-up roll 52 and a felt 58 that runs above the press blanket 10.
Due to a high pressing force prevailing in the press nip 50, the water is extracted from the web 56 in the press nip 50 and is absorbed by the felt 58 and in part by grooves or blind holes provided in the press blanket 10.
The press blanket 10 takes the form of an endless, hose-shaped tape comprisingan elastomeric matrix16, preferably consisting of polyurethane. The matrix 16 is reinforced by axial threads 22 extending in the axial direction of the press blanket 10 and transversely to the direction of movement 60 of the web 56, as shown in Fig. 5. on the axial threads 22, there are provided equally spaced circumferential threads 20 extending in the circumferential direction of the hose-like press blanket, i.e. substantially in the direction of movement 60 of the web (Fig. 1). The circumferential threads 20 are spiral]y wound over the axial threads 22, as will be described in more detail further below, with reference to Fig. 4.
The axial threads 22 and the circumferential threads 20 form together a thread structure as described for example in US 5,320,702.
A plurality of grooves 12, extending likewise in the circumferen-tial direction of the press blanket, i.e. in parallel to the direction of movement 60 of the web, open toward the surface 14 of the press blanket 10 that faces the web 56. The grooves 12, which are equally spaced one to the other, serve for absorbing the liquid being extracted from the web 56 as it passes the nip 50. In the illustration of Fig. 1, the grooves 12 exhibit a U-shaped cross-section 12, although a different, for example a rectangular cross-section would be possible as well.
Between the grooves 12 and the circumferential threads 20, there is arranged a continuous fabric layer 18, extending in parallel to the surface 14 of the press blanket 10 and being formed by a fabric tape 25, which is spirally wound into the compound in the circumferential direction of the press blanket 10, above the circumferential threads 20.
The fabric tape 25 is wound in partially overlapping arrangement so that single-layer areas 26 alternate with double-layer areas 24 where the fabric tape overlies part of the neighboring layer.
When the press blanket 10 according to the invention is used in a pressing device for extracting water from a web 56 in a press nip 50 of a papermaking machine, the high forces acting in the nip may in the course of time lead to the formation of fissures which, due to the notch stresses caused by the grooves 12, will in most of the cases propagate from the grooves 12 in the radial direction of the press blanket 10, i.e. in a direction toward the axial threads22. During further operation of the press blanket 10 additional such fissures may be formed, and the fissures may enlarge. But due to the presence of the continuous fabric layer 18 such fissures are prevented from propagating beyond the layer 18, which means that any further enlargement of the fissures and, thus, possible leakage and unserviceability of the press blanket 10 will be avoided. ~11 in all, the service life and operating safety of the press blanket 10 is, thus, significantly improved.
Preferably, the axial threads 20 and the circumferential threads 22 consist of high-strength plastic fibers, for example aramide fibers. The fabric tape 18 may consist of a textile fabric, for example a non-woven fabric, and may be less strong than the reinforcing threads 20, 22, the dimensional stability of the press blanket 10 being already ensured by the reinforcing threads 20, 22.
Given the fact that the fabric tape 18 extends in the circum-ferential direction of the press blanket 10, i.e. in the direction of movement 60 of the web, it is sometimes even possible to do without the circumferentially extending rein-forcing threads 20, as indicated in Fig. 2. The press blanket illustrated in Fig. 2 is designated generally by reference numeral 30. Those parts that correspond to Fig~ 1 are indicated by the same reference numerals as in Fig~ 1. Modified elements are also designated by the same reference numerals, followed only by an apostrophe. The fabric layer 18' consists again of a fabric tape 25', that is spirally wound -in the circumferential direction of the press blanket 10 - into the press blanket area between the grooves 12 and the axial threads 22. In order to arrive at a higher strength, it is ensured, by having the fabric tape 25' fully overlap during winding, that a continuous double fabric layer 18' is obtained so that each area 24' of the fabric tape 25' overlaps an underlying area 26' of the fabric tape.
In order to further increase the strength of the press blanket 10, the fabric tape 25' may also consist of a high-strength material, for example of glass fibers or aramide fibers.
The structure of the fabric tape 18 is illustrated schematically in Fig. 3. It is apparent that the fabric tape 18 is formed predominantly of threads 19 that extend in the longitudinal direction of the fabric tape and that are held together by one or more threads 21 extending transversely thereto. Preferably, approximately 75 % of the threads of the fabric tape are oriented in the circumferential direction, while 25 % of the threads are oriented in axial direction.
A device for producing a press blanket according to the invention is illustrated in Fig. 4 and is indicated generally by reference numeral 40. The device comprises a cylindrical casting mold 42, between the two end faces of which the axial threads are mounted in mutually parallel arrangement at a predetermined distance from the surface. Polyurethane is fed via a line 48 and applied from the top through a casting nozzle 49, while the casting mold 42 is simultaneously rotated about its center axis 44, in the direction indicated by arrow 46, and the casting nozzle 49 is advanced by means of a carriage in a direction parallel to the center axis 44 so that a cylindrical circumferen-tial surface will gradually form during the continuous castingoperation. During this process, the compound passes through the axial threads 22 until it comes to deposit on the casting mold 42, thereby forming the elastomeric matrix 16 of the press blanket 10.
At the same time, the circumferential threads 20 and, on top of the latter, the fabric tape 18 are spirally wound into the compound, which provides a particularly good adhesion effect between the matrix and the reinforcing threads 20, 22 and the fabric tape 18, respectively.
If a press blanket according to Fig. 2 is to be produced, no circumferential threads 20 are used so that only the fabric tape is wound into the compound, the degree of overlapping being preferably selected in this case - as mentioned before -in such a way that a double fabric layer is obtained.
Claims (9)
1. A press blanket for a pressing device for extracting liquid from a web passing through a press nip of a papermaking machine, comprising a layer of an elastomeric material, said elastomeric material layer comprising axial threads, extending axially and transversely to the direction of movement of the web, and further comprising circumferential threads extending above said axial threads in a circumferen-tial direction substantially in the direction of movement of the web, said elastomeric material layer further comprising a fabric layer extending substantially in parallel to said circumferential threads and being embedded in said elastomeric material layer.
2. The press blanket of claim 1, wherein said fabric layer comprises a fabric tape being spirally wound and comprising a number of consecutive layers which overlap each other at their edges.
3. The press blanket of claim 2, wherein said fabric tape extends substantially in circumferential direction.
4. The press blanket of claim 1, comprising a plurality of recesses extending from an outer surface of said press blanket facing said web.
5. The press blanket of claim 4, wherein said plurality of recesses are configured as grooves.
6. The press blanket of claim 4, wherein said recesses are configured as blind holes.
7. The press blanket of claim 2, wherein said fabric tape comprises approximately 60 to 90 % fibers extending in circumferential direction within said elastomeric layer, and approximately 40 to 10 % fibers extending in axial direction within said elastomeric layer.
8. A method for producing a press blanket for a pressing device for extracting liquid from a web passing through a press nip of a papermaking machine, said method comprising the steps of:
- providing a casting mold defining an axial direction and a circumferential direction;
- mounting a plurality of axial threads extending in axial direction around a circumference of said casting mold;
- winding a fabric tape around said axial threads; and - simultaneously pouring a layer of elastomeric material onto said casting mold, said elastomeric material enclosing said axial and circumferential threads and said fabric tape therein.
- providing a casting mold defining an axial direction and a circumferential direction;
- mounting a plurality of axial threads extending in axial direction around a circumference of said casting mold;
- winding a fabric tape around said axial threads; and - simultaneously pouring a layer of elastomeric material onto said casting mold, said elastomeric material enclosing said axial and circumferential threads and said fabric tape therein.
9. The method of claim 8, wherein at least one circumferential thread is wound spirally around said axial threads and said tape is wound over said circumferential thread.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4438354.1 | 1994-10-27 | ||
| DE19944438354 DE4438354A1 (en) | 1994-10-27 | 1994-10-27 | Paper web pressure roller mantle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2161486A1 true CA2161486A1 (en) | 1996-04-28 |
Family
ID=6531813
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2161486 Abandoned CA2161486A1 (en) | 1994-10-27 | 1995-10-26 | Press blanket and method for producing the same |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH08209578A (en) |
| CA (1) | CA2161486A1 (en) |
| DE (1) | DE4438354A1 (en) |
| FI (1) | FI955090A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6149771A (en) * | 1997-06-03 | 2000-11-21 | Voith Sulzer Papiermaschinen Gmbh | Method for manufacturing a press jacket and a press jacket made in accordance with this method |
| US6929592B2 (en) | 2001-11-15 | 2005-08-16 | Voith Paper Patent Gmbh | Roll cover |
| CN106544919A (en) * | 2015-09-18 | 2017-03-29 | 福伊特专利有限公司 | For the body and spreader roll of spreader roll |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19651766A1 (en) * | 1996-12-12 | 1998-06-18 | Voith Sulzer Papiermasch Gmbh | Paper-making machine press mantle |
| JP3408416B2 (en) * | 1998-02-26 | 2003-05-19 | 市川毛織株式会社 | Shoe press belt and method of manufacturing the same |
| DE19819526A1 (en) * | 1998-04-30 | 1999-11-04 | Voith Sulzer Papiermasch Gmbh | Press jacket |
| DE50112624D1 (en) | 2001-04-18 | 2007-07-26 | Stowe Woodward Ag | nip press |
| JP4592230B2 (en) * | 2001-07-31 | 2010-12-01 | 日本フエルト株式会社 | Papermaking belt |
| EP1293601A1 (en) | 2001-09-17 | 2003-03-19 | Stowe Woodward Aktiengesellschaft | Belt for shoe press |
| US7014733B2 (en) | 2002-05-14 | 2006-03-21 | Stowe Woodward L.L.C. | Belt for shoe press and shoe calender and method for forming same |
| US20050003724A1 (en) * | 2003-07-02 | 2005-01-06 | Fitzpatrick Keith | Substrate for endless belt for use in papermaking applications |
| US7654296B2 (en) * | 2003-11-24 | 2010-02-02 | Albany International Corp. | Grooved single facer belt |
| DE102004011665A1 (en) * | 2004-03-10 | 2005-10-06 | Stowe Woodward Ag | Integral shoe press belt |
| CN1673452B (en) | 2004-03-26 | 2013-11-06 | 市川毛织株式会社 | Shoe press belt |
| DE102004033751A1 (en) * | 2004-07-13 | 2006-02-02 | Voith Paper Patent Gmbh | roll shell |
| WO2015063143A1 (en) | 2013-10-30 | 2015-05-07 | Voith Patent Gmbh | Press cover and method for producing a press cover |
| DE102015217942A1 (en) | 2015-09-18 | 2017-03-23 | Voith Patent Gmbh | Press cover and method for producing such |
| US11098450B2 (en) | 2017-10-27 | 2021-08-24 | Albany International Corp. | Methods for making improved cellulosic products using novel press felts and products made therefrom |
| DE102018122779A1 (en) * | 2018-09-18 | 2020-03-19 | Voith Patent Gmbh | Press jacket, its use as well as press roll and shoe press |
| DE102018122780A1 (en) * | 2018-09-18 | 2020-03-19 | Voith Patent Gmbh | Press jacket, its use as well as press roll and shoe press |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4022800C1 (en) * | 1990-07-18 | 1991-09-19 | J.M. Voith Gmbh, 7920 Heidenheim, De | |
| DE4202731C2 (en) * | 1992-01-31 | 1997-04-17 | Voith Gmbh J M | Press jacket for a shoe press |
-
1994
- 1994-10-27 DE DE19944438354 patent/DE4438354A1/en not_active Withdrawn
-
1995
- 1995-10-19 JP JP29493795A patent/JPH08209578A/en active Pending
- 1995-10-25 FI FI955090A patent/FI955090A/en not_active Application Discontinuation
- 1995-10-26 CA CA 2161486 patent/CA2161486A1/en not_active Abandoned
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6149771A (en) * | 1997-06-03 | 2000-11-21 | Voith Sulzer Papiermaschinen Gmbh | Method for manufacturing a press jacket and a press jacket made in accordance with this method |
| US6929592B2 (en) | 2001-11-15 | 2005-08-16 | Voith Paper Patent Gmbh | Roll cover |
| CN106544919A (en) * | 2015-09-18 | 2017-03-29 | 福伊特专利有限公司 | For the body and spreader roll of spreader roll |
Also Published As
| Publication number | Publication date |
|---|---|
| DE4438354A1 (en) | 1996-05-02 |
| JPH08209578A (en) | 1996-08-13 |
| FI955090A0 (en) | 1995-10-25 |
| FI955090A (en) | 1996-04-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |