AU739688B2 - Moulded filter media comprising a sheet of porous nonwoven material - Google Patents

Moulded filter media comprising a sheet of porous nonwoven material Download PDF

Info

Publication number
AU739688B2
AU739688B2 AU88767/98A AU8876798A AU739688B2 AU 739688 B2 AU739688 B2 AU 739688B2 AU 88767/98 A AU88767/98 A AU 88767/98A AU 8876798 A AU8876798 A AU 8876798A AU 739688 B2 AU739688 B2 AU 739688B2
Authority
AU
Australia
Prior art keywords
filter medium
medium according
filter
sheet
particles
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.)
Ceased
Application number
AU88767/98A
Other versions
AU8876798A (en
Inventor
Ian Christison Sayers
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Madison Filter 981 Ltd
Original Assignee
Madison Filter 981 Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Madison Filter 981 Ltd filed Critical Madison Filter 981 Ltd
Publication of AU8876798A publication Critical patent/AU8876798A/en
Assigned to MADISON FILTER 981 LIMITED reassignment MADISON FILTER 981 LIMITED Alteration of Name(s) of Applicant(s) under S113 Assignors: SCAPA GROUP PLC
Application granted granted Critical
Publication of AU739688B2 publication Critical patent/AU739688B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/10—Supported membranes; Membrane supports
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/10—Supported membranes; Membrane supports
    • B01D69/107—Organic support material
    • B01D69/1071—Woven, non-woven or net mesh
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D25/00—Filters formed by clamping together several filtering elements or parts of such elements
    • B01D25/12—Filter presses, i.e. of the plate or plate and frame type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D25/00—Filters formed by clamping together several filtering elements or parts of such elements
    • B01D25/12—Filter presses, i.e. of the plate or plate and frame type
    • B01D25/176—Filter presses, i.e. of the plate or plate and frame type attaching the filter element to the filter press plates, e.g. around the central feed hole in the plates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
    • B01D39/1638—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being particulate
    • B01D39/1653—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being particulate of synthetic origin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
    • B01D39/1692—Other shaped material, e.g. perforated or porous sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/20—Other self-supporting filtering material ; Other filtering material of inorganic material, e.g. asbestos paper, metallic filtering material of non-woven wires
    • B01D39/2027—Metallic material
    • B01D39/2031—Metallic material the material being particulate
    • B01D39/2034—Metallic material the material being particulate sintered or bonded by inorganic agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0002—Organic membrane manufacture
    • B01D67/0004—Organic membrane manufacture by agglomeration of particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0002—Organic membrane manufacture
    • B01D67/0004—Organic membrane manufacture by agglomeration of particles
    • B01D67/00041—Organic membrane manufacture by agglomeration of particles by sintering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0002—Organic membrane manufacture
    • B01D67/0023—Organic membrane manufacture by inducing porosity into non porous precursor membranes
    • B01D67/003—Organic membrane manufacture by inducing porosity into non porous precursor membranes by selective elimination of components, e.g. by leaching
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/02—Inorganic material
    • B01D71/022—Metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/26—Polyalkenes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/26—Polyalkenes
    • B01D71/261—Polyethylene
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/26—Polyalkenes
    • B01D71/262—Polypropylene
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/40—Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/40—Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
    • B01D71/401—Polymers based on the polymerisation of acrylic acid, e.g. polyacrylate
    • B01D71/4011—Polymethylmethacrylate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/44—Polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, not provided for in a single one of groups B01D71/26-B01D71/42
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2325/00—Details relating to properties of membranes
    • B01D2325/40—Fibre reinforced membranes

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Filtering Materials (AREA)

Description

WO 99/12634 PCT/G B98/02617 MOULDED FILTER MEDIA COMPRISING A SHEET OF POROUS NONWOVEN
MATERIAL
This invention relates to filter media such as filter cloths for use in filter plate presses.
A filter plate press comprises a plurality of movable plates which when pressed together define a number of chambers into which slurry to be filtered can be fed. Each chamber has filtration means often in the form of filter cloths, so that solid residue is retained within the chamber and filtrate is removed from the chamber. The residue forms a filter cake and by various known means the moisture content of the cake can be reduced.
When the filtration process is completed the plates are separated so that filter cake can be removed from the chambers. After cleaning and rearranging of the plates a further filtration cycle can be carried out.
The filter plates typically have central feed holes via which the slurry progressively enters the chamber of the filter press. The liquid filtrate passes thrni gnh the filter cloths secured on bohnth sides of the Plate extending over recessed filtration areas in the plates from which recessed areas the liquor is drained. The solids are retained and collect on the filter cloths to form the filter cake. The cloths are secured to the top surfaces of the plates and a seal is formed between the peripheries of adjacent plates defining chambers between the plates. The chambers are connected to each other by the central feed holes through the plates and the filter cloths WO 99/12634 PCT/GB98/02617 -2about the feed holes may be sealed and connected by an impervious barrel neck connector.
During operation the flow of slurry impinges against the cloths and forces the cloths into the recessed surfaces of the plates. This leads to distortion of the cloth, particularly at the plate corners and edges at locations where the cloth is in contact with raised bosses projecting from the plane of the filter plate towards the fabric to provide support points.
This distortion of the cloth structure results in interstices in the cloth opening up, allowing larger particles than the designed maximum size to pass through the cloth which reduces filtration efficiency and performance.
This problem is particularly noted with filter cloths based on woven fabrics.
A further problem with standard cloths for such filter plates is that the weight and adhesion of the cake to the filter cloth causes the cloth to leave the contours of the plate and subsequently when the cake is removed a the press resealed the cloth Awill frAinequntl h in a slirhtly different position having been displaced for example by lateral forces in scraping the cake from the cloth. This causes the cloth to become deformed into the plate recesses into a different position. As a result of this creep, over a period of time this has the effect of stretching the cloth to add further to the problems of opening interstices.
It has been proposed therefore to provide woven monofilament warp/weft or monofilament warp/multifilament weft fabrics substantially comprising polypropylene yarns since the low melting point of the polymer makes the cloths easy to thermoform into the plate recesses and contours. However, distortion-susceptible woven structures are still present. Also it has been proposed (US Patent 4931178) to provide a porous PTFE membrane on a woven substrate to form a filter cloth. This proposal is also subject to the same disadvantages due to the effects of distortion on the woven substrate. GB-A-2283926 discloses a filter made from partially fused particles which may be polymeric or of metal, and may be located on a base structure or a reinforcement structure may be embedded therein.
This structure again does not address the problem-of filter medium distortions in filter presses.
It is an object of the invention to provide a filter medium principally but not e exclusively for use in press filters which remedies the above noted weakness of eee* known woven based filter cloths.
According to this invention there is provided a pre-moulded filter medium comprising a sheet of porous non-woven material which is pre-moulded to conform and snugly fit into the recesses and contours of a filter press plate, the sheet including a support structure sandwiched between layers of the porous non-woven material.
The porous non-woven material is preferably a sintered sheet made for example of partially fused particles. These may be of a suitable polymer or WO 99/12634 PCT/GB98/0261 7 -4may be metal or a ceramic material. Polymer is preferred because the resultant material has greater flexibility.
The porous nonwoven material may however be a film or sheet of coagulated polymer, a microporous foam, or a "porum" a sheet of polymer such as synthetic or natural rubber which has been rendered porous by leaching out particles of soluble material such as sodium chloride or sugar that have been blended with the polymer prior to extrusion or moulding of the sheet).
The sheet may be made or preformed in moulds corresponding to the contours of a respective design of filter plate.
The sheet material may be reinforced to improve its strength with a supporting structure such as a perforated membrane, a nonwoven mesh, a spiral link fabric, incorporation of chopped fibres, including bicomponent fibres or parallel yarns. Woven or knitted fabrics may also be used as a reinforcement without detriment as the woven mesh plays no part in the as-fr e n wove pls. i filtration action and thus any distortion encountered will have no effect in the filtration performance.
By way of example, two preferred embodiments of the invention will be briefly described with reference to the accompanying drawings, wherein:- Fig. 1 is a diagrammatic cross-section of a first embodiment of filter WO 99/12634 PCT/GB98/02617 medium fabric according to the invention; and Fig. 2 is a similar view of a second embodiment of filter medium fabric according to the invention.
In Fig. 1 a filter medium fabric is shown in an enlarged diagrammatic cross-section. The cloth comprises a filter layer 1 which is made of particles 2 of a suitable synthetic plastics material, e.g. a polyolefin, which are partially adhered to one another by being subjected to heating to achieve superficial softening and to pressure. A suitable material is disclosed in GB-A-2,283,926 wherein particles of partially fused polyethylene or polypropylene form a filter material.
The filter layer 1 is supported to give mechanical strength by a membrane substrate 3 which forms a mesh or lattice of a plastics material providing apertures or pores 4 for the passage of filtrate liquor and possibly reinforced internally by yarns such as 5 extending in one or both directions "1 5 of the mesh o lattice. l h a membrane may be mrlae n accordance with GB-A-2202893.
The particles of the filter layer 1 are depicted as being of relatively small size forming two or three layers with pores and interstices between the solid residue particles forming flow channels through the filter layer 1 for the filtrate liquor, whilst particles above the designed size are retained by the filter layer.
WO 99/12634 PCT/GB98/0261 7 -6- In Fig. 2 a filter medium in the form of a filter cloth comprises a filter layer 11, of larger particles which again are fused together to form a coherent porous layer. This layer is supported for mechanical strength on a spiral link fabric 12 which may be substantially as disclosed in GB-A- 2051154. Pairs of cross-yarns 13 are connected by interdigitated spirals 14 to link the yarns 13 into a continuous open fabric.
The filter layer is again preferably made by partial fusion of e.g.
polyethylene, polypropylene or EVA particles in accordance with GB-A- 2283926.
A porous filter cloth may alternatively be made by casting a solution of a polymer, e.g. an acrylic or methacrylic based thermoset resin or thermoplastic polymer, such as polymethyl methacrylate, in a suitable mould of appropriate shape, and driving off moisture by heat to form a porous structure.
The filter cloth may alternatively be manufactured using a vibrational moulding technique, as described for example in EP-A-010914.
When mounting a filter medium of the invention such as a filter cloth on a press filter, a hot former may be applied to the area around the central feed aperture to compact the medium and prevent leakage in this gasket region by rendering the cloth impermeable. The barrel neck may be welded to the cloth and/or the cloth preferred, by a similar technique to assist WO 99/12634 PCT/GB98/02617 -7mating with the barrel neck in the central feed aperture area.
These embodiments are described by way of example only and as already stated a wide variety of sintered materials including metals and ceramics may be used to provide the nonwoven fabric as well as other nonwoven structures. The fabric may be unsupported or supported by structures other than those particularly described.
The filter media of the invention have a number of advantages, including quick and easy installation. It may also be possible to use integrally moulded barrel neck connectors, filter press seal members and/or couplings for mating with corresponding profiles on the inside and/or outside of the plate, and further it may be possible to provide a combined filter material and plate.

Claims (18)

1. A pre-moulded filter medium comprising a sheet of porous non-woven material which is pre-moulded to conform and snugly fit into the recesses and contours of a filter press plate, the sheet including a support structure sandwiched between layers of the porous non-woven material.
2. A filter medium according to claim 1, wherein said support comprises a perforated membrane.
3. A filter medium according to claim 1, wherein said support structure p comprises a spiral link fabric.
4. A filter medium according to anyone of claims 1, 2 or 3 wherein the porous S• non-woven material comprises fused polymeric particles provided in layers of differing sized particles on opposite faces of the support structure. ooo.oi
5. A filter medium according to claim 1, wherein the porous non-woven material •o is a sintered sheet made of partially fused particles.
6. A filter medium according to claim 2, wherein said particles are of a polymeric 0oo material.
7. A filter medium according to claim 3, wherein said polymeric material comprises polyethylene, or polypropylene or EVA.
8. A filter medium according to claim 1, formed from a solution of an acrylic or methacrylic thermoset resin or polymer cast in a suitable mould.
9. A filter medium according to claim 5, wherein the resin is polymethyl methacrylate.
A filter medium according to claim 2, wherein said particles are of a metal.
11. A filter medium according to claim 2, wherein said particles are of a ceramic material.
12. A filter according to claim 1 or 3, wherein said non-woven material comprises a film or sheet of corrugated polymer.
13. A filter according to claim 1, wherein said non-woven material comprises a film of microporous foam.
14. A filter medium according to claim 1, wherein said non-woven materialises polymer rendered porous by leaching out soluble particles blended with the polymer. 10
15. A filter medium according to claim 2, wherein said membrane is non-woven mesh containing reinforcing yarns extending in at least one common direction.
16. A filter medium according to claim 11 wherein said supporting structure is a woven or knitted fabric.
17. A filter medium according to any of claims 1 to 12 wherein said sheet is .S 1 reinforced by incorporation of chopped fibres in said sheet. a.
18. A filter medium according to claim 17, wherein said chopped fibres include biocomponent fibres. Dated this 9 th day of August, 2001. MADISON FILTER 981 LIMITED By its Patent Attorneys MADDERNS a /7
AU88767/98A 1997-09-06 1998-09-01 Moulded filter media comprising a sheet of porous nonwoven material Ceased AU739688B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GBGB9718841.1A GB9718841D0 (en) 1997-09-06 1997-09-06 Moulded Filter Cloths
GB9718841 1997-09-06
PCT/GB1998/002617 WO1999012634A1 (en) 1997-09-06 1998-09-01 Moulded filter media comprising a sheet of porous nonwoven material

Publications (2)

Publication Number Publication Date
AU8876798A AU8876798A (en) 1999-03-29
AU739688B2 true AU739688B2 (en) 2001-10-18

Family

ID=10818581

Family Applications (1)

Application Number Title Priority Date Filing Date
AU88767/98A Ceased AU739688B2 (en) 1997-09-06 1998-09-01 Moulded filter media comprising a sheet of porous nonwoven material

Country Status (7)

Country Link
EP (1) EP1009513A1 (en)
AU (1) AU739688B2 (en)
BR (1) BR9811768A (en)
CA (1) CA2302589A1 (en)
GB (1) GB9718841D0 (en)
WO (1) WO1999012634A1 (en)
ZA (1) ZA988029B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050218057A1 (en) * 2004-03-31 2005-10-06 Ngee Lee C Filter plate assembly
DE102015220433B3 (en) 2015-10-20 2016-06-23 Ibs Filtran Kunststoff-/ Metallerzeugnisse Gmbh Filter device for an oil filter and suction filter and pressure filter
WO2018078578A1 (en) * 2016-10-31 2018-05-03 Flsmidth A/S Snap-on porous filter media for filter press plates

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2051154A (en) * 1979-05-26 1981-01-14 Haaksbergen T T Bv Method for the production of a link-belt and a link-belt produced thereby
US4931178A (en) * 1985-04-16 1990-06-05 W. L. Gore & Associates, Inc. Filter cloth assembly
US5508095A (en) * 1993-11-16 1996-04-16 Scapa Group Plc Papermachine clothing

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0653235A1 (en) * 1993-11-16 1995-05-17 Scapa Group Plc Filter
GB9502486D0 (en) * 1995-02-09 1995-03-29 Scapa Group Plc Filtration apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2051154A (en) * 1979-05-26 1981-01-14 Haaksbergen T T Bv Method for the production of a link-belt and a link-belt produced thereby
US4931178A (en) * 1985-04-16 1990-06-05 W. L. Gore & Associates, Inc. Filter cloth assembly
US5508095A (en) * 1993-11-16 1996-04-16 Scapa Group Plc Papermachine clothing

Also Published As

Publication number Publication date
BR9811768A (en) 2000-08-29
ZA988029B (en) 1999-03-03
EP1009513A1 (en) 2000-06-21
GB9718841D0 (en) 1997-11-12
AU8876798A (en) 1999-03-29
WO1999012634A1 (en) 1999-03-18
CA2302589A1 (en) 1999-03-18

Similar Documents

Publication Publication Date Title
CN102006917B (en) Filter compound material, method for the production thereof and flat filter elements made of the filter compound material
EP2231300B1 (en) Filter device
US2788901A (en) Fused edge filter unit
CN101224364B (en) Filter unit and filter unit panel
EP1427515B1 (en) Process for making a fluid processing module
EP0325582A1 (en) Molded panel filter.
US5057217A (en) Integral supported filter medium assembly
KR101946852B1 (en) Filter for flat type water treatment
US4931178A (en) Filter cloth assembly
AU592866B2 (en) Length of material comprising needle felt fabric and open pore plastic foam
US4839045A (en) Thermoplastic filter plate for a filter press
CA1180287A (en) Polymer filter cartridge of glass fibers coated with fluoroethylene polymer and process for preparing the same
AU739688B2 (en) Moulded filter media comprising a sheet of porous nonwoven material
US5445746A (en) Method for dewatering a porous wet web
NO311809B1 (en) Method of manufacturing a web of materials
US5143628A (en) Method of the dewatering of sludge
US20060180553A1 (en) Method for filtering fluids and device for implementing said method
EP2542320A2 (en) Filtering element and method for its manufacture
KR100286511B1 (en) Strip material and preparation method thereof
CN109126231A (en) A kind of high elastic diaphragm filter board and preparation method thereof
CA2306387A1 (en) Injection mold for insert-molding a synthetic material around a filter material, filter for the filtration of fluids and method for producing such filter
EP1410887A2 (en) Apparatus for producing thin tiles of cement paste
JP2001314712A (en) Filter cloth for filter press
US7090770B2 (en) Filter cloth and method for producing the same
CN220003085U (en) Filter pressing plate and filter press

Legal Events

Date Code Title Description
PC1 Assignment before grant (sect. 113)

Owner name: MADISON FILTER 981 LIMITED

Free format text: THE FORMER OWNER WAS: SCAPA GROUP PLC

FGA Letters patent sealed or granted (standard patent)
MK14 Patent ceased section 143(a) (annual fees not paid) or expired