CA2097834A1 - Paper machine clothing - Google Patents
Paper machine clothingInfo
- Publication number
- CA2097834A1 CA2097834A1 CA002097834A CA2097834A CA2097834A1 CA 2097834 A1 CA2097834 A1 CA 2097834A1 CA 002097834 A CA002097834 A CA 002097834A CA 2097834 A CA2097834 A CA 2097834A CA 2097834 A1 CA2097834 A1 CA 2097834A1
- Authority
- CA
- Canada
- Prior art keywords
- sheet
- article
- layer
- polyfluorocarbon
- paper
- 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
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/0027—Screen-cloths
- D21F1/0063—Perforated sheets
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/0027—Screen-cloths
- D21F1/0036—Multi-layer screen-cloths
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F7/00—Other details of machines for making continuous webs of paper
- D21F7/08—Felts
- D21F7/083—Multi-layer felts
Landscapes
- Paper (AREA)
Abstract
The present invention is concerned with paper machine clothing and in particular paper machine clothing for use in a pressing section of a paper machine, suitable for use in high temperature pressing or impulse drying. A particular feature of this invention is a sheet contacting surface comprising a polyfluorocarbon polymer which may be in the form of fibrous sheets.
Description
2~37~3~
IMPROVEMENTS IN AND RELATING TO PAPER MACHINE CLOTHING
DESCRIPTION
This invention relates to paper machine clothing and has particular-reference to paper machine clothing for ~.:
use in the pressing and drying sections of a paper machine, although the invention described herein is e~ually app7icable in other sections of a paper making machine.
A conventional paper making machine forms a web by depositing a slurry of pulp fibres to be formed into a paper sheet onto, for example, a travelling Foudrinier wire. After initial dewatering on the Foudrinier wire, the forming paper sheet or web is trans~erred to a press section where the web passes through one or more nips comprised of either roll or shoe combinations.
During this time, the sheet is consolidated and further properties of the sheet may be developed. Thereafter, the web pasRes over a series of heated dryer drums (and optionally through a calender) and i6 then wound onto a .
- . . . - - ,, . . . . . ~ . :
. .
.: . -- -.. ~,. - . . .. : : :
:. . . - . - . . . , , ~ . -, . , . :, . : .
WO 92/10607 PCT/GB91/02158~
2~97~34 roll. There are many variations in the various sections of the machine such as the forming or press sections. In such a machine, the web usually arrives at the press section with about 80% wet base moisture S (a ratio of water to fibre ~ water) and leaves the press section with approximately 60% moisture ratio (or 40% dryness). The remaining moisture has to be removed by thermal evaporation in the dryer section as the web .. . ................................... . . _ . . .
passes over a series of heated drums. In a typical paper making machine, such as that manufacturing newsprint, a significant number of dryer drums will be employed, sometimes on the order of 50 to 70 drums per machine. Each dryer drum is expensive to construct and to operate and requires a provision of steam fittings and a supply of steam or other heat source for,each drum.
.~
In recent years, the principle of impulse drying has introduced. Impulse drying is a method of dewatering a paper sheet by incorporating both high temperatuIe and pres~ure in a press section of a paper making machine.
During this process, the surface of the press roll is usually heated to a temperature of 150C or greater, and is in direct contact with the paper. With such a . .
`` ` ' '' ' ~ ' .: ,' ', '. :- , :. , . ' ~. ~, . . . .
203~3~
IMPROVEMENTS IN AND RELATING TO PAPER MACHINE CLOTHING
DESCRIPTION
This invention relates to paper machine clothing and has particular-reference to paper machine clothing for ~.:
use in the pressing and drying sections of a paper machine, although the invention described herein is e~ually app7icable in other sections of a paper making machine.
A conventional paper making machine forms a web by depositing a slurry of pulp fibres to be formed into a paper sheet onto, for example, a travelling Foudrinier wire. After initial dewatering on the Foudrinier wire, the forming paper sheet or web is trans~erred to a press section where the web passes through one or more nips comprised of either roll or shoe combinations.
During this time, the sheet is consolidated and further properties of the sheet may be developed. Thereafter, the web pasRes over a series of heated dryer drums (and optionally through a calender) and i6 then wound onto a .
- . . . - - ,, . . . . . ~ . :
. .
.: . -- -.. ~,. - . . .. : : :
:. . . - . - . . . , , ~ . -, . , . :, . : .
WO 92/10607 PCT/GB91/02158~
2~97~34 roll. There are many variations in the various sections of the machine such as the forming or press sections. In such a machine, the web usually arrives at the press section with about 80% wet base moisture S (a ratio of water to fibre ~ water) and leaves the press section with approximately 60% moisture ratio (or 40% dryness). The remaining moisture has to be removed by thermal evaporation in the dryer section as the web .. . ................................... . . _ . . .
passes over a series of heated drums. In a typical paper making machine, such as that manufacturing newsprint, a significant number of dryer drums will be employed, sometimes on the order of 50 to 70 drums per machine. Each dryer drum is expensive to construct and to operate and requires a provision of steam fittings and a supply of steam or other heat source for,each drum.
.~
In recent years, the principle of impulse drying has introduced. Impulse drying is a method of dewatering a paper sheet by incorporating both high temperatuIe and pres~ure in a press section of a paper making machine.
During this process, the surface of the press roll is usually heated to a temperature of 150C or greater, and is in direct contact with the paper. With such a . .
`` ` ' '' ' ~ ' .: ,' ', '. :- , :. , . ' ~. ~, . . . .
203~3~
process, the resulting paper sheet dryness is significantly increased to 60% or higher. The effectiveness of such a system is such that the number of dryer drums in a paper making machine can be S su~stantially reduced.
The principle of operation underlying impulse drying is believed to be that the heated roll forms a zone of steam in the paper sheet during pressing of the sheet which drives out liquid water as the steam passes through the sheet. Generation of this steam front, and high temperature of the press roll provides rather severe conditions for the press fabric.
In order to withstand this high temperature, the press fabric should have sufficient thermal resistance to allow continued exposure to high temperature steam and occasional exposure to the high temperature press roll directly during breaks in the paper sheet passing therethrough.
In addition, this press fabric should adequately release the paper sheet after the nip to proYide for acceptable sheet runnabLlity. Also the press fabric . ~
.~ , .
.. , . . ~ . .
`~ . . . ' ' . ` `` - ', ~ :
. . - .
: . .. . . .
- ~ . . ;.- . -. . ~ . . .
.
WO 92/10607 2 0 3 7 8 3 ~ PCI'/GB9ltO2158 --should minimize rewet of the sheet as it exits the nip to produce a sheet with maximum dryness. These properties should be combined with sufficient mechanical durability to withstand the severe conditions of the impulse drying process. According to traditional pressing theory, a press fabric should also provide and maintain adequate permeability for the water leaving the sheet.
.. ..
~ccording to the present invention, therefore, there is provided an article of paper machine clothing which comprises a first woven base layer and a second sheet contacting layer carried thereby, characterised in that the sheet contacting surface of said second layer lS comprises a polyfluorocarbon polymer.
The polyfluorocarbon polymer may be in a fibrous form.
The said second layer may comprise a fibrous structure of batt or staple fibre which is needled to the base layer. The second layer may typically comprise a batt of 100~ polyfluorocarbon polymers or may be a blend of fibres of polyfluorocarbon with any high temperature resistant fibres such, for example, as polyamide, ~;~ polyaramid, polyester, po}yimide, polyetherketone, , ~' ' . , ' .
, . .
2~7~34 polybenzLmidazole or polyether imide. The polyfluorocarbon may be polytetrafluoroethylene of the type commercially available under the trade name "TEFLON" ~PTFE).
s In an alternative aspect of the pre~ent invention, the sheet contacting surface may contain an effective amount of polyfluorocarbon to achieve the desirable _ .... . . . . . . .
properties for the impulse drying process. The effecti~e amount of polyfluorocarbon may be in the form of a discrete surface layer, a coating on the surface on the fibres constituting the said second layer, a pre-formed nonwoven layer of polyfluorocarbon, or a finely wo~en polyfluorocarbon fabric, each of which can be needled or otherwise bonded to the surface to incorporate it as part of the surface layer.
In another aspect of the present invention, the surface layer incorporating polyfluorocarbon may be in a form other than a textile form. The sheet contacting surface of said second layer may comprise a film of polyfluorocarbon. The layer may for example be formed , j .
by bondlng, l~minating or other~i~e att~ching a . .
i" ,, ,, : .. . ..
.. . : .
. . .: , . - , . . . : , :
~: . ~ ..
2d~78~4 polyfluorocarbon polymer film, to the remainder of the second layer.
Either a monolithic, perforated or microporous film can be employed. A surface layer can also be formed by coating with a fluoro~arbon emulsion or suspension, by spraying, dipping or other suitable methods. The surface layer may also be formed by direct application . .
of a fluorocarbon in particulate form.
In the practice of this invention, it has been noted that after multiple compressions within the press nip press fabrics have signîficantly reduced air permeability, yet surprisingly still continue to produce high sheet dryness values; the more so since traditional press fabrics having such low air permeabilities do not normally dewater the sheet effectively. --Following is a description by way of example only and with reference to the accompanying drawings of methods of carrying the invention into effect.
. : .
, -.
' , . .
- , WO 92/10607 PCT/~B91/02158 20378~4 , :
In the drawings:-Figures 1 (a), (b) and (c) are a series of graphsrelating to Example 2.
s Fig~re 2 is a photomicrograph of the sheet contacting surface of a PTFE surfaced press fabric of Example 3.
.. . ............................ . . .
An experimental pilot press fabric, made up of 11 test sections, was prepared usiAg conventional carding and needling proce~ses. Each experimental section represented either a candidate fibre or a test structure. Each candidate fibre was prepared into a -cA~ded web and a total of eight card web layers were combined to conqtruct each experimental section. All sections were needled onto a common woven base fabric.
The experimental felt was installed on a pilot impulse drying machine and run at the following conditions:
Nip pressure: ~75 pli Roll temperature: 160C (320F) Fabric speed: 107 fpm . .
,: .
.
,;
. . , . ~ i . : . . . ~ . . . . : -:
WO 92tl0607 PCT/GB91/02158-`
2~783~ ~
The handsheets used during this test were a newsprint grade comprised of 71% groundwood, 2~% high yield sulfite. Five of the eleven test sections in the experimental felt were constructed with a paper contacting surface comprised of at least 50% by weight Teflon. Of the 11 sections tested during this study, all five Teflon containing felts produced paper sheets with the highest dryness, ranging between 70% and 7S%
~~ ~~ dryness. A11 of the other high temperature resistant materials tested (such as polyara~id, po~yetheretherketone, and an aromatic poly~ide 6T), produced paper sheets with lower dryness values (between 61% and 69%).
EXAMP~E 2 A series of experimental press fabrics were constructed with varying percentages of Teflon fibre in the paper contacting layers of the fabric. The blends ranged from 0% Teflon to 100% Teflon, in increments of 25%.
Each fabric ~ample was conditioned at 21C for 500 cycles at 1000 psi, and then tested on a laboratory impul~e dryer tester at the following conditions:
, - .
~, , ~ . ., .. - : . : ' . .
~ , . , : .. .. , . ' ' ' ' - , . ,: ' ' . - ':, ,. ' ' ' ' . ' . .. . . , . .:
- . . , :: - . -- . . : : . ~ :
WO 92/10607 2 ~ 3 ~ 8 3 ~ PcTrGB91/02lsx g Pressure: 5500 KPa Nip Residence: 45 msec Upper Platen Temp: 190C
The paper stock used for these tests was 100~ sleached Softwood Kraft with a 500 CSF prepared into 50 g/m2 handsheets with an ingoing dryness of 36%. The ingoing felt moisture ratio for each fabric was 0.~5. During testing, final paper dryness and felt moisture gain were determined. In addition, each felt's air permeability after conditioning was also measured.
Results of the study clearly show that as the percentage of Teflon fibre in the paper contacting layer increases, both paper dryness and felt moisture gain increase significantly, while the press fabricls air permeability decreases. Traditionally, lower air permeability in a press fabric usually relates to lower dewatering capability; however, in this case, the trend is opposite. Under the test conditions discussed above, approximately 10~ higher paper dryness values are achieved with the sample having a 100% Teflon paper contacting layer compared to the sample containing 0 Te~lon, while at the same time air permeability , ': . , : . .-.... ' '' . , : ' . : : , . ,: , -... . . - ., .
. . .. . , -, . ...
.
wo 92/10607 2 0 ~ 7 8 3 ~ PCT1GB91/02158-decreased from 12.2 cfm for the 0% Teflon sample to 4.2 cfm for the 100~ Teflon sample.
The results of this study are shown below in Table 1 and are displayed in Figure 1 of the accompanying drawings.
Table l. Teflon B~end Pross Fa~ S~rucsure S~udy . w . . .
No I Felt ¦ Itandstleet ¦ Felt Gain FsltAir !
Composition I ; I- - - Permeabi~i~y ~0 TAeflon ¦ Y Cry Final ¦ ~cfm~
l 1 ! o% T~flon ¦ 5~.0 ¦ 24.8 1 2 1 25% Teflon 1 60.4 1 25.0 1 11 9 3 ¦ 50% Teflon ¦ 6~8 ¦ 28.8 ¦ 12.1 .
4 ¦ 75% Teflon 6~ ¦ 29.9 ¦ 6.1 , .. , .
1 1~0% Teflon ¦ 65.6 352 ¦ 4.2 lS . ............ ..
An experimental press fabric contain_ng a 100% Teflon paper contacting layer was tested on a pilot paper machine with an impulse drying roll and an extended nip press shoe. The conditions used for this trial were as ~0~ 8:
' ~ ' ' ' -:
~ .
.: . . . - . . - . , . - ~ : ~ - . -~ . . -. . - : :. ., - , - ': .:- '; ~ : . ' '.' . ' : . . , :
Wo 92~10607 2 0 3 7 ~ ~ L~ PCT/GB91/02158 Maximum nip pressure: 600 pli Machine speed: 820 m/min (2500fpm) Hot Roll Temperature: 177C (350F) Paper basis weight: 45-50 g/m2 Ingoing paper dryness: 25-36%
During this trial, a final paper dryness greater than 60~ was obtained. Subsequent to this trial, a sample of the used press ~abric was returned to the laboratory and examined. Visual examination showed that the susface was heavily sealed and glazed. An SEN
photomicrograph of this surface ~see Figure 2 of the - accompanying drawings) confirmed this condition. A
specimen was removed from this area of the fabric and subsequently tested on a laboratory Lmpulse dryer tester for dewatering using 50 g/m2 handsheets at 36% initial dryneqs. Regardless of this sealed surface, : the results, surprisingly, showed paper dryness as high as 65%. Through our experience, any other press fabrics having a similar glazed or sealed surface would be expected to produce a very low level o dewatering, thus low paper dryness.
. ' - ' ' ,: .......... . ~, ............. : . .
.: . -: . . ..
.
.
The principle of operation underlying impulse drying is believed to be that the heated roll forms a zone of steam in the paper sheet during pressing of the sheet which drives out liquid water as the steam passes through the sheet. Generation of this steam front, and high temperature of the press roll provides rather severe conditions for the press fabric.
In order to withstand this high temperature, the press fabric should have sufficient thermal resistance to allow continued exposure to high temperature steam and occasional exposure to the high temperature press roll directly during breaks in the paper sheet passing therethrough.
In addition, this press fabric should adequately release the paper sheet after the nip to proYide for acceptable sheet runnabLlity. Also the press fabric . ~
.~ , .
.. , . . ~ . .
`~ . . . ' ' . ` `` - ', ~ :
. . - .
: . .. . . .
- ~ . . ;.- . -. . ~ . . .
.
WO 92/10607 2 0 3 7 8 3 ~ PCI'/GB9ltO2158 --should minimize rewet of the sheet as it exits the nip to produce a sheet with maximum dryness. These properties should be combined with sufficient mechanical durability to withstand the severe conditions of the impulse drying process. According to traditional pressing theory, a press fabric should also provide and maintain adequate permeability for the water leaving the sheet.
.. ..
~ccording to the present invention, therefore, there is provided an article of paper machine clothing which comprises a first woven base layer and a second sheet contacting layer carried thereby, characterised in that the sheet contacting surface of said second layer lS comprises a polyfluorocarbon polymer.
The polyfluorocarbon polymer may be in a fibrous form.
The said second layer may comprise a fibrous structure of batt or staple fibre which is needled to the base layer. The second layer may typically comprise a batt of 100~ polyfluorocarbon polymers or may be a blend of fibres of polyfluorocarbon with any high temperature resistant fibres such, for example, as polyamide, ~;~ polyaramid, polyester, po}yimide, polyetherketone, , ~' ' . , ' .
, . .
2~7~34 polybenzLmidazole or polyether imide. The polyfluorocarbon may be polytetrafluoroethylene of the type commercially available under the trade name "TEFLON" ~PTFE).
s In an alternative aspect of the pre~ent invention, the sheet contacting surface may contain an effective amount of polyfluorocarbon to achieve the desirable _ .... . . . . . . .
properties for the impulse drying process. The effecti~e amount of polyfluorocarbon may be in the form of a discrete surface layer, a coating on the surface on the fibres constituting the said second layer, a pre-formed nonwoven layer of polyfluorocarbon, or a finely wo~en polyfluorocarbon fabric, each of which can be needled or otherwise bonded to the surface to incorporate it as part of the surface layer.
In another aspect of the present invention, the surface layer incorporating polyfluorocarbon may be in a form other than a textile form. The sheet contacting surface of said second layer may comprise a film of polyfluorocarbon. The layer may for example be formed , j .
by bondlng, l~minating or other~i~e att~ching a . .
i" ,, ,, : .. . ..
.. . : .
. . .: , . - , . . . : , :
~: . ~ ..
2d~78~4 polyfluorocarbon polymer film, to the remainder of the second layer.
Either a monolithic, perforated or microporous film can be employed. A surface layer can also be formed by coating with a fluoro~arbon emulsion or suspension, by spraying, dipping or other suitable methods. The surface layer may also be formed by direct application . .
of a fluorocarbon in particulate form.
In the practice of this invention, it has been noted that after multiple compressions within the press nip press fabrics have signîficantly reduced air permeability, yet surprisingly still continue to produce high sheet dryness values; the more so since traditional press fabrics having such low air permeabilities do not normally dewater the sheet effectively. --Following is a description by way of example only and with reference to the accompanying drawings of methods of carrying the invention into effect.
. : .
, -.
' , . .
- , WO 92/10607 PCT/~B91/02158 20378~4 , :
In the drawings:-Figures 1 (a), (b) and (c) are a series of graphsrelating to Example 2.
s Fig~re 2 is a photomicrograph of the sheet contacting surface of a PTFE surfaced press fabric of Example 3.
.. . ............................ . . .
An experimental pilot press fabric, made up of 11 test sections, was prepared usiAg conventional carding and needling proce~ses. Each experimental section represented either a candidate fibre or a test structure. Each candidate fibre was prepared into a -cA~ded web and a total of eight card web layers were combined to conqtruct each experimental section. All sections were needled onto a common woven base fabric.
The experimental felt was installed on a pilot impulse drying machine and run at the following conditions:
Nip pressure: ~75 pli Roll temperature: 160C (320F) Fabric speed: 107 fpm . .
,: .
.
,;
. . , . ~ i . : . . . ~ . . . . : -:
WO 92tl0607 PCT/GB91/02158-`
2~783~ ~
The handsheets used during this test were a newsprint grade comprised of 71% groundwood, 2~% high yield sulfite. Five of the eleven test sections in the experimental felt were constructed with a paper contacting surface comprised of at least 50% by weight Teflon. Of the 11 sections tested during this study, all five Teflon containing felts produced paper sheets with the highest dryness, ranging between 70% and 7S%
~~ ~~ dryness. A11 of the other high temperature resistant materials tested (such as polyara~id, po~yetheretherketone, and an aromatic poly~ide 6T), produced paper sheets with lower dryness values (between 61% and 69%).
EXAMP~E 2 A series of experimental press fabrics were constructed with varying percentages of Teflon fibre in the paper contacting layers of the fabric. The blends ranged from 0% Teflon to 100% Teflon, in increments of 25%.
Each fabric ~ample was conditioned at 21C for 500 cycles at 1000 psi, and then tested on a laboratory impul~e dryer tester at the following conditions:
, - .
~, , ~ . ., .. - : . : ' . .
~ , . , : .. .. , . ' ' ' ' - , . ,: ' ' . - ':, ,. ' ' ' ' . ' . .. . . , . .:
- . . , :: - . -- . . : : . ~ :
WO 92/10607 2 ~ 3 ~ 8 3 ~ PcTrGB91/02lsx g Pressure: 5500 KPa Nip Residence: 45 msec Upper Platen Temp: 190C
The paper stock used for these tests was 100~ sleached Softwood Kraft with a 500 CSF prepared into 50 g/m2 handsheets with an ingoing dryness of 36%. The ingoing felt moisture ratio for each fabric was 0.~5. During testing, final paper dryness and felt moisture gain were determined. In addition, each felt's air permeability after conditioning was also measured.
Results of the study clearly show that as the percentage of Teflon fibre in the paper contacting layer increases, both paper dryness and felt moisture gain increase significantly, while the press fabricls air permeability decreases. Traditionally, lower air permeability in a press fabric usually relates to lower dewatering capability; however, in this case, the trend is opposite. Under the test conditions discussed above, approximately 10~ higher paper dryness values are achieved with the sample having a 100% Teflon paper contacting layer compared to the sample containing 0 Te~lon, while at the same time air permeability , ': . , : . .-.... ' '' . , : ' . : : , . ,: , -... . . - ., .
. . .. . , -, . ...
.
wo 92/10607 2 0 ~ 7 8 3 ~ PCT1GB91/02158-decreased from 12.2 cfm for the 0% Teflon sample to 4.2 cfm for the 100~ Teflon sample.
The results of this study are shown below in Table 1 and are displayed in Figure 1 of the accompanying drawings.
Table l. Teflon B~end Pross Fa~ S~rucsure S~udy . w . . .
No I Felt ¦ Itandstleet ¦ Felt Gain FsltAir !
Composition I ; I- - - Permeabi~i~y ~0 TAeflon ¦ Y Cry Final ¦ ~cfm~
l 1 ! o% T~flon ¦ 5~.0 ¦ 24.8 1 2 1 25% Teflon 1 60.4 1 25.0 1 11 9 3 ¦ 50% Teflon ¦ 6~8 ¦ 28.8 ¦ 12.1 .
4 ¦ 75% Teflon 6~ ¦ 29.9 ¦ 6.1 , .. , .
1 1~0% Teflon ¦ 65.6 352 ¦ 4.2 lS . ............ ..
An experimental press fabric contain_ng a 100% Teflon paper contacting layer was tested on a pilot paper machine with an impulse drying roll and an extended nip press shoe. The conditions used for this trial were as ~0~ 8:
' ~ ' ' ' -:
~ .
.: . . . - . . - . , . - ~ : ~ - . -~ . . -. . - : :. ., - , - ': .:- '; ~ : . ' '.' . ' : . . , :
Wo 92~10607 2 0 3 7 ~ ~ L~ PCT/GB91/02158 Maximum nip pressure: 600 pli Machine speed: 820 m/min (2500fpm) Hot Roll Temperature: 177C (350F) Paper basis weight: 45-50 g/m2 Ingoing paper dryness: 25-36%
During this trial, a final paper dryness greater than 60~ was obtained. Subsequent to this trial, a sample of the used press ~abric was returned to the laboratory and examined. Visual examination showed that the susface was heavily sealed and glazed. An SEN
photomicrograph of this surface ~see Figure 2 of the - accompanying drawings) confirmed this condition. A
specimen was removed from this area of the fabric and subsequently tested on a laboratory Lmpulse dryer tester for dewatering using 50 g/m2 handsheets at 36% initial dryneqs. Regardless of this sealed surface, : the results, surprisingly, showed paper dryness as high as 65%. Through our experience, any other press fabrics having a similar glazed or sealed surface would be expected to produce a very low level o dewatering, thus low paper dryness.
. ' - ' ' ,: .......... . ~, ............. : . .
.: . -: . . ..
.
.
Claims (11)
1. An article of paper machine clothing characterised by having a sheet-contacting surface comprising a polyfluorocarbon polymer.
2. An article as claimed in claim 1 characterised in that the polyfluorocarbon polymer is present in one or more of fibres, sheet or coating.
3. An article as claimed in claim 1 or claim 2 characterised in that the sheet contacting surface is fibrous and comprises a batt structure of staple fibre.
4. An article as claimed in any preceding claim characterised in that the sheet-contacting surface comprises a distinct layer carried by a base layer or substrate.
5. An article as claimed in claim 4 characterised in that the base layer or substrate is a woven layer.
6. An article as claimed in any preceding claim characterised in that the sheet-contacting surface is part of a sheet contacting layer, said layer being secured to the base layer.
7. An article as claimed in claim 6 characterised in that the sheet-contacting layer is a batt fibre structure comprising a polyfluorocarbon polymer.
8. An article as claimed in any one of claims 3 to 7 characterised in that the batt structure includes a proportion of high temperature resistance fibres, selected from polyamide, polyaramid, polyester, polyimide, polyetherketone and polybenzelmidizole and polyetherimide.
9. An article as claimed in any preceding claim characterised in that the polyfluorocarbon is present in sheet form as a discrete surface layer or a surface coating on fibres.
10. An article as claimed in any one of claims 2 to 9 wherein the polyfluorocarbon is a finely woven polyfluorocarbon fabric needled or bonded to a substrate.
11. An article as claimed in any one of claims 2 to 9 characterised in that the sheet contacting surface comprises a polyfluorocarbon film or sheet further characterised in that said film or sheet is monolithic, perforated or microporous.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB909026475A GB9026475D0 (en) | 1990-12-05 | 1990-12-05 | Improvements in and relating to paper machine clothing |
| GB9026475.5 | 1990-12-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2097834A1 true CA2097834A1 (en) | 1992-06-06 |
Family
ID=10686539
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002097834A Abandoned CA2097834A1 (en) | 1990-12-05 | 1991-12-05 | Paper machine clothing |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0564474A1 (en) |
| JP (1) | JPH06506020A (en) |
| KR (1) | KR100243849B1 (en) |
| AU (1) | AU660632B2 (en) |
| BR (1) | BR9107208A (en) |
| CA (1) | CA2097834A1 (en) |
| FI (1) | FI932593A0 (en) |
| GB (1) | GB9026475D0 (en) |
| MX (1) | MX9102362A (en) |
| WO (1) | WO1992010607A1 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9125889D0 (en) * | 1991-12-05 | 1992-02-05 | Albany Research Uk | Improvements in and relating to paper machine clothing |
| GB9220351D0 (en) | 1992-09-25 | 1992-11-11 | Albany Research Uk | Improvements in and relating to paper machine felts |
| GB9407462D0 (en) * | 1994-04-15 | 1994-06-08 | Scapa Group Plc | Papermachine clothing |
| US5569358A (en) * | 1994-06-01 | 1996-10-29 | James River Corporation Of Virginia | Imprinting felt and method of using the same |
| US6284380B1 (en) * | 1997-02-25 | 2001-09-04 | Albany International Corp. | Paper machine clothing and a method of coating same |
| US6136437A (en) * | 1997-10-07 | 2000-10-24 | Astenjohson, Inc. | Industrial fabric and yarn made from an improved fluoropolymer blend |
| US6171446B1 (en) * | 1998-10-19 | 2001-01-09 | Shakespeare Company | Press felt with grooved fibers having improved dewatering characteristics |
| DE19854732C1 (en) * | 1998-11-26 | 2000-09-14 | Inventa Ag | Core-jacket bicomponent fiber and its use |
| JP4522212B2 (en) * | 2004-09-29 | 2010-08-11 | イチカワ株式会社 | Paper transport felt and press machine of paper machine equipped with the paper transport felt |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3121660A (en) * | 1961-02-13 | 1964-02-18 | Jr Edward H Hall | Fourdrinier wire and method of making the same |
| GB1455843A (en) * | 1973-01-31 | 1976-11-17 | Scapa Porritt Ltd | Paper makers wet felts |
| US4457968A (en) * | 1983-08-02 | 1984-07-03 | Niagara Lockport Industries, Inc. | Process for manufacture of a poly (perfluoroolefin) belt and a belt made thereby |
| US4579771A (en) * | 1984-08-10 | 1986-04-01 | Asten Group, Inc. | Laminated spiral mesh papermakers fabric |
| US4697397A (en) * | 1985-08-10 | 1987-10-06 | Shimizu Construction Co. Ltd. | Trussed girder, roof framing using the trussed girder and method of constructing the roof framing of a building using the trussed girder |
-
1990
- 1990-12-05 GB GB909026475A patent/GB9026475D0/en active Pending
-
1991
- 1991-12-04 MX MX9102362A patent/MX9102362A/en not_active IP Right Cessation
- 1991-12-05 BR BR919107208A patent/BR9107208A/en not_active Application Discontinuation
- 1991-12-05 KR KR1019930701681A patent/KR100243849B1/en not_active IP Right Cessation
- 1991-12-05 WO PCT/GB1991/002158 patent/WO1992010607A1/en not_active Application Discontinuation
- 1991-12-05 CA CA002097834A patent/CA2097834A1/en not_active Abandoned
- 1991-12-05 JP JP4500504A patent/JPH06506020A/en active Pending
- 1991-12-05 AU AU90232/91A patent/AU660632B2/en not_active Ceased
- 1991-12-05 EP EP19920900112 patent/EP0564474A1/en not_active Withdrawn
-
1993
- 1993-06-07 FI FI932593A patent/FI932593A0/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| WO1992010607A1 (en) | 1992-06-25 |
| FI932593A (en) | 1993-06-07 |
| JPH06506020A (en) | 1994-07-07 |
| GB9026475D0 (en) | 1991-01-23 |
| AU660632B2 (en) | 1995-07-06 |
| BR9107208A (en) | 1993-11-03 |
| KR100243849B1 (en) | 2000-02-01 |
| EP0564474A1 (en) | 1993-10-13 |
| AU9023291A (en) | 1992-07-08 |
| MX9102362A (en) | 1992-06-01 |
| FI932593A0 (en) | 1993-06-07 |
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Legal Events
| Date | Code | Title | Description |
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| EEER | Examination request | ||
| FZDE | Dead |