GB2026567A - Nonwoven filter fabrics - Google Patents

Nonwoven filter fabrics Download PDF

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Publication number
GB2026567A
GB2026567A GB7831487A GB7831487A GB2026567A GB 2026567 A GB2026567 A GB 2026567A GB 7831487 A GB7831487 A GB 7831487A GB 7831487 A GB7831487 A GB 7831487A GB 2026567 A GB2026567 A GB 2026567A
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GB
United Kingdom
Prior art keywords
fabric
finish
fibers
viscose rayon
fibres
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.)
Granted
Application number
GB7831487A
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GB2026567B (en
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Kendall Co
Original Assignee
Kendall Co
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 Kendall Co filed Critical Kendall Co
Priority to GB7831487A priority Critical patent/GB2026567B/en
Priority to NL7808294A priority patent/NL7808294A/en
Priority to BE189799A priority patent/BE869638A/en
Publication of GB2026567A publication Critical patent/GB2026567A/en
Application granted granted Critical
Publication of GB2026567B publication Critical patent/GB2026567B/en
Expired legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
    • D04H1/425—Cellulose series
    • 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
    • B01D39/18—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being cellulose or derivatives thereof
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
    • D04H1/425—Cellulose series
    • D04H1/4258—Regenerated cellulose series
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
    • D04H1/587—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives characterised by the bonding agents used
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
    • D04H1/64—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
    • D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
    • D06M13/10—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing oxygen
    • D06M13/144—Alcohols; Metal alcoholates
    • D06M13/148—Polyalcohols, e.g. glycerol or glucose
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/0604—Arrangement of the fibres in the filtering material
    • B01D2239/064—The fibres being mixed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/12—Special parameters characterising the filtering material
    • B01D2239/1233—Fibre diameter

Abstract

The invention relates to nonwoven filter fabrics comprising cellulosic fibers and methods of manufacturing such fabrics. The nonwoven filter fabric consists of a compressed fibrous array comprising at least in part cellulosic fibers which contain as a finish a liquid aliphatic polyhydroxy alcohol which is free or substantially free from fatty acids. The alcohol provides the array with sufficient strength to be usable as a filter yet allows waste pieces of fabric to be disintegrated to recycle the fibres.

Description

SPECIFICATION Nonwoven filter fabrics This invention relates to nonwoven filter fabrics comprising cellulosic fibers and methods of man ufacturing such fabrics.
Many fluids, particularly potable liquids such as milk, beer, wines and the like, are subjected during processing to a filtration operation to remove unwanted and undesirable sediments. In the case of milk, for example, it was at one time a regular practice to strain the milk as produced on the farm, through a layerofflannel orthrough multiple layers of gauze. The substantial cost of woven fabrics made it desirable to reclaim the filter after each use, that is to say, to wash and scour the flannel or gauze so that no traces of souring milk would remain to contaminate the next milking. Such reclamation was tedious and cumbersome, and was frequently slighted or even over-looked.Dairy sanitarians responsible for milk quality have for many years, therefore, recommended the use of disposable or one-use filter disks or squares, and their use is now practically universal.
In producing milk on a dairy farm, it is customary to pourthefluid milkthrough a metal strainer in the lower portion of which is mounted a filter pad. For ear in cleaning, such strainers are generally round, with nc crevices or corners, and the filter pads are circular, and are referred to as disks. For convenience, however, filter pads will hereinafter be referred to as filter disks, regardless of the exact shape of the filter pad.
Earliest nonwoven filter disks were die-cut from a carded or garnetted array of bleached cotton fibers, and in some areas such disks are still used. It was early recognized, however, that such disks were sub jest to certain disadvantages. In bulk they were dif ficultto separate, one from another, and moreover in use the fibers tended to distort and separate, leaving thin areas in the disk through which sediment could pass. This tendency of early disks to "wash", as it was commonly termed, was especially noticeable if the dairyman tried to accelerate the filtration process by raising and then dropping the metal strainer againstthe rim of the largermilkcan in which the milk is eventually collected.
Attempts to improve this situation led first to nonwoven filter disks which were bonded on their surface with starch, dextrin, or edible gums. Later, increased wet strength and resistance to rupture in use were provided by bonding the filter material by hot calendering an array of cotton fibers and thermoplastic fibers, as described in U.S. patent 2433531, or by the more recent use of polymeric bonding agents as described in U.S. patent 3307706.
Such expedients have provided enhanced wet strength to filter disks, but they suffer from a substantial economic disadvantage. The nonwoven fabric coming from the range is frequently wound in multiple layers on a creel, from which the material is removed, laid out flat on a cutting table, and cut into piles of disks by means of circular dies. Cutting circular disks from fabrics, as is known, involves a waste factor of 35% to 40% or higher, depending on the cutting method. Since the waste is bonded, by one means or another, salvaging the valuable fiber content from the waste involves an expensive processing with scouring chemicals to remove the binder, followed by rinsing and drying the recovered fibers.
Indeed, some binders used in manufacturing nonwoven filter media are refractory to any chemical removal short of treatments which also embrittlethe fiber.
Attempts have been made to improve the strength of binder-free fibrous arrays by means of compression, particularly between heated calender rolls, plain or embossed. When such a process is applied to arrays of cotton fibers, or mixtures of cotton and viscose fibers, an improvement in strength is noted.
However, as the percentage of viscose fibers in a cotton-viscose blend is increased, the strength of the compressed product decreases drastically, a 75% viscose-25% cotton blend having substantially less strength than a 75% cotton-25% viscose blend. Filter disks composed of a preponderance of viscose fibers, bonded solely by compression, are not acceptable due to their weakness and theirtendencyto distort or rupture in use. Presumably this is due to the inherent nature of cotton fibers versus viscose fibers, the former being by nature curled, twisted, and convoluted, whereas viscose fibers are less able to entangle with each other, even when crimped.For economic reasons it would be desirable to substitute viscose fibers for cotton fibers in a filter disk, since cotton has become relatively expensive and also requires a costly wet scouring, bleaching, and drying before it is suitable for use in filtering potable liquids. Raw cotton fibers are almost impossible to compress with any degree of permanence.
It has now quite unexpectedly been found that the lubricant or finish applied to cotton or to commercial viscose rayon fibers can be altered so as to have a profound effect on the strength of nonwoven filter fabrics comprising such fibers. In order to facilitate the opening lapping and carding of cellulosic fibers, it is standard commercial practice for the fiber manufacturer or processor to apply to the fibers a finish, which is commonly a "soap-fatty acid" (sodium oleate-oleic acid) finish, applied to the fibers at a level of 0.2% to 0.4% based on the weight of the fibers. Such soap-fatty acid finishes facilitate the processing of the fibers, but do not act as a bonding agent. Therefore, as mentioned above, as the percentage of viscose rayon in a cotton-viscose blend is increased, the strength of compressed fibrous arrays decreases.
According to a first aspect of the present invention, there is provided a nonwoven filter fabric consisting of a compressed fibrous array comprising at in least part cellulosic fibers which contain as a finish a liquid aliphatic polyhydroxy alchohol which is free or substantially free from fatty acids.
According to a second aspect of the present invention, there is provided a method of manufacturing a nonwoven filter fabric comprising the steps of forming a fibrous array comprising at least in part cellulosic fibers which contain as a finish a liquid aliphatic polyhydroxy alcohol which is free or substantially free from fatty acids and subjecting the fibrous array to compression.
The cellulosic fibers may contain an aliphatic polyhydroxy alcohol finish, such as glycerine, at a level of 0.05% to 0.50%, with a range of 0.1% to 0.3% being preferred. Such cellulosic fibers can be readily processed through the customary equipment used in the production of nonwoven fabrics, but in addition, when blended with other cellulosic fibers and subjected to compression, they impart to nonwoven fabrics processed therefrom an unexpected and as yet unexplained increase in strength.
Furthermore, the waste from the die-cutting of filter disks, 35% to 40% of the material, may be recovered and reused by subjecting it to the normal operations customarily employed in the process: i.e., fiber opening, lapping, and carding. Although a fiber-to-fiber bond is set up in the process of this invention, the bond is of a frangible nature, unlike the bonds set up by the use of heat-bonded thermoplastic fibers or polymeric binders. It is advisable to regulate the variables in the process so that the dry machine direction strength of a strip of material 5 cm. wide does not substantially exceed 2,000 grams, in order that the waste may remain recoverable and reusable without resorting to special processing.
EXAMPLES All of the filter disks in the examples hereinafter described were made by hot-calendering an array of super-imposed carded fibrous webs.
EXAMPLE 1 A series of four commercially available filter disks, from different manufacturers, were analyzed for performance and physical characteristics. The fiber content of each disk was approximately 50% bleached cotton - 50% viscose rayon with regular commercial finish. The pysical characteristics of the disks were as follows: Average weight ........................................ 46 grams per square meter.
Average tensile strength, dry, machine direction ................................. 230 grams per 5cm. wide strip.
Average flow time ........................................ 36 Seconds.
Average sediment retention ........................................ 46% of 50 micron particles.
Flow time is the time in seconds required for a given volume of liquid to pass through a filter disk: sediment retention is the percentage of sediment, of standard mesh size, retained on the filter disk in use.
Both of these variables are measured in a standardized set of laboratory tests, and are an indication of the performance to be expected from a filter disk.
They are not an absolute measure of performance on the farm, since local variables will influence performance - such as the temperature and viscosity of the milk the presence or absence of garget, etc., and the nature of the sediment whether it is coarse bedding chips and hair, or fine silt. Nevertheless, laboratory tests correlated with field tests, under varying conditions, do provide a set of laboratory standards by which the acceptability or nonacceptability of a filter disk can be predicted.
EXAMPLE2 The mixture of 50% bleached cotton-50% regular viscose rayon was replaced by a blend of 50% bleached cotton - 25% regular viscose rayon - 25% viscose rayon with a 0.15% glycerine finish. The physical constants were as follows: Weight ........................................48 grams per square meter.
Tensile strength, dry, machine direction ................. 610 grams per 5 cm. wide strip.
Flow time 36 seconds.
Sediment retention .......................52% 52% ofmicron particles.
The tensile strength of the experimental product, therefore, is 2.65 times the tensile strength to be expected from comparative available commercial products composed of similar cotton-viscose blends.
As the percentage of viscose with glycerine finish is increased in the fiber blend, the strength of the resultant filter material is also increased.
EXAMPLE 3 A disk composed of 100% viscose rayon with 0.15% glycerine finish had the following characteristics: Weight ........................................ 48 grams per square meter.
Tensile strength: Dry, machine direction ................ 2,000 grams per 5cm. wide strip.
Dry, cross direction ....................... 500 grams per 5cm. wide strip.
Wet, machine direction ................ 225 grams per 5cm. wide strip.
Wet, cross direction ...................... 70 grams per 5cm. wide strip.
Flow ....................................... time 27 seconds.
Sediment retention ....................... 62% of50 micron particles.
A comparable disk of similar weight but composed of 100% viscose fibers with a commercial soap-fatty acid finish, was not commercially acceptable due to low dry and wet tensile strengths and to its tendency to distort and develop thin places in use, causing low sediment retention and milk of unacceptable quality.
In general, in filter disks composed of cotton fibers, viscose fibers, or blends thereof, an increase in the dry and wet tensile strengths of from 250% to 700% may be expected when the customary soapfatty acid finish is replaced by a glycerine finish.
As little as 25% viscose fibers with glycerine finish will more than double the strength of a viscosecotton blend, as noted above. When the filter media contain a substantial proportion of viscose fibers, it is customary to adjust the flow time vs. sediment retention percentage by blending coarse viscose fib ers (10 to 20 denier) with finer viscose fibers (1.5 to 5 denier), depending on the nature of the liquid to be filtered and the sediment to be removed. In general, as might be expected, the use of coarse fibers results in more rapid flow times, but at the expense of sediment retention. It will be obvious to those skilled in the art that a desired balance of flow time versus sediment retention can be achieved by blending fibers of varying deniers.In the practice of this invention, it has been found convenient to use fine viscose fibers, say 2.2 denier, with a desired proportion of coarser denier viscose fibers, such as 10 denier, and to have the glycerine finish applied to the fine fibers for maximum bonding efficiency.
Although the above discussion has concerned cellulosic fibers with a glycerine finish, it will be apparent that other liquid aliphatic polyhydroxy alcohols such as propylene glycol and the like will serve a similar purpose, since the bonding effect may be presumed to be due to an affinity between the aliphatic polyhydroxy compounds and the hydroxyl groups present in cellulosic fibers. Glycerine remains the glycol of choice for the filtration of potable liquids, due to its recognized non-toxic nature and its widespread usage in tinctures, medicinal syrups, foods, and other products meant for ingestion.
Various ancillary benifits are realized from the practice of the present invention, in addition to increased strength in use. Processing is facilitated, inasmuch as the temperatures used in hot calendering to compress the carded fibrous array may be decreased from the customary 1 00 C-1 60 C to 750C or less, with a consequent increase in speed of the production line. Also, with a stronger material, breakage and waste in the creeling and die-cutting operations is decreased.

Claims (6)

1. A nonwoven filter fabric consisting of a compressed fibrous array comprising at least in part cellulosic fibers which contain as a finish a liquid aliphatic polyhydroxy alcohol which is free or substantially free from fatty acids.
2. A fabric according to claim 1 in which the finish on the cellulosic fibers is present to the extent of 0.1% to 0.3 /O based on the weight of the cellulosic fibers.
3. A fabric according to claim 1 or 2 in which the cellulosic fibers containing the polyhydroxy alcohol finish constitute from 25% to 100% of the weight of the fabric.
4. A fabric according to any of the preceding claims in which the cellulosic fibers comprise a blend of coarse viscose rayon fibers of from 10 to 20 denier and finer viscose rayon fibers of from 1.5 to 5 denier.
5. A fabric according to claim 4, wherein only the said finer viscose rayon fibers contain the polyhyd roxy alcohol finish.
6. A filter disk according to claim 1, madefrom a nonwoven fabric substantially as hereinbefore described in Example2 or3.
6. A fabric according to any of the preceding claims in which the cellulosic fibers comprise a blend of bleached cotton fibers and viscose rayon fibers.
7. A fabric according to any of the preceding claims in which the aliphatic polyhydroxy alcohol is glycerine.
8. A fabric according to any of the preceding claims in which the dry tensile strength thereof does not exceed 2,000 grams per 5cm. wide strip.
9. A nonwoven filter fabric substantially as hereinbefore described in Example 2 or 3.
10. A method of manufacturing a nonwoven fil ter fabric comprising the steps of forming a fibrous array comprising at least in part cellulosic fibers which contain as a finish a liquid aliphatic polyhyd roxy alcohol which is free or substantially free from fatty acids and subjecting the fibrous array to com pression.
11. A method according to claim 10, in which the fibrous array is compressed by hot calendering.
12. A method according to claim 10 or 11 wherein the cellulosic fibers containing the polyhyd roxy alcohol finish are viscose rayon fibers.
13. A method according to claim 12, wherein the fibrous array comprises a blend of viscose rayon fib ers containing the polyhydroxy alcohol finish and other viscose rayon fibers containing no polyhyd roxy alcohol finish.
14. A method according to claim 13, in which the viscose rayon fibers containing no polyhydroxy alcohol finish are of from 10 to 20 denier and wherein the viscose rayon fibers containing the polyhydroxy alcohol finish are of from 1.5 to 5 denier.
15. A method according to any of claims 10 to 14, wherein the fibrous array comprises a blend of bleached cotton fibers and viscose rayon fibers.
16. A method according to any of claims 10 to 15, b in which the fibers of the fibrous array are of such characteristics and are blended in such proportions as to provide a fabric having a dry tensile strength not exceeding 2,000 grams per 5cm. width strip.
17. A method of manufacturing a nonwoven filter fabric according to claim 10 and substantially as hereinbefore described.
18. A filter made from a fabric according to any of claims 1 to 9.
19. Afilter made from a fabric manufactured by a method according to any of claims 10 to 17.
New claims or amendments to claims filed on 5 March 1979 Superseded claims 1 to 19 CLAIMS
1. A filter disk made of hot calendered nonwoven fabric composed of viscose rayon fibres or of a blend of viscose rayon and cotton fibres, at least 25% by weight of the fibres being constituted by viscose rayon fibres containing glycerine as a finish in an amount of 0.1 - 0.3 /O by weight based on the weight of the fibres and applied to the fibres prior to calendering, said fabric containing no bonding agent otherthan said finish.
2. A filter disk according to claim 1, in which the fibres containing the glycerine finish constitute from 25% to 100% of the weight of the fabric.
3. A fabric according to either of the preceding claims, in which the fibres comprise a blend of coarse viscose rayon fibres of 10 to 20 denier and finer viscose rayon fibres of 1.5 to 5 denier.
4. A fabric according to claim 3, wherein only the said finer viscose rayon fibres contain the glycerine finish.
5. A filter disk according to any one of the preceding claims in which the dry tensile strength of the nonwoven fabric does not exceed 2,000 grams per 5cm. wide strip.
GB7831487A 1978-07-28 1978-07-28 Nonwoven filter fabrics Expired GB2026567B (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB7831487A GB2026567B (en) 1978-07-28 1978-07-28 Nonwoven filter fabrics
NL7808294A NL7808294A (en) 1978-07-28 1978-08-08 NON WOVEN TEXTILE MATERIAL FOR FILTERS.
BE189799A BE869638A (en) 1978-07-28 1978-08-09 NON-WOVEN FILTER CLOTH

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB7831487A GB2026567B (en) 1978-07-28 1978-07-28 Nonwoven filter fabrics
NL7808294A NL7808294A (en) 1978-07-28 1978-08-08 NON WOVEN TEXTILE MATERIAL FOR FILTERS.
BE189799A BE869638A (en) 1978-07-28 1978-08-09 NON-WOVEN FILTER CLOTH

Publications (2)

Publication Number Publication Date
GB2026567A true GB2026567A (en) 1980-02-06
GB2026567B GB2026567B (en) 1982-10-13

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB7831487A Expired GB2026567B (en) 1978-07-28 1978-07-28 Nonwoven filter fabrics

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BE (1) BE869638A (en)
GB (1) GB2026567B (en)
NL (1) NL7808294A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0352888A2 (en) * 1988-07-26 1990-01-31 International Paper Company Filtration fabric produced by wet laid process
GB2246373A (en) * 1990-07-12 1992-01-29 Arco Chem Tech Nonwoven fabric
ITMI20111155A1 (en) * 2011-06-24 2012-12-25 Nextmaterials S R L CORRUGATED CARDBOARD FILTERS TREATED AND HAVING IMPROVED ANTIBACTERIAL EFFECTIVENESS AS WELL AS METHOD FOR THEIR IMPLEMENTATION, WITHOUT POTENTIALLY HARMFUL SUBSTANCES

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0352888A2 (en) * 1988-07-26 1990-01-31 International Paper Company Filtration fabric produced by wet laid process
EP0352888A3 (en) * 1988-07-26 1990-10-24 Veratec, Inc. Filtration fabric produced by wet laid process
GB2246373A (en) * 1990-07-12 1992-01-29 Arco Chem Tech Nonwoven fabric
ITMI20111155A1 (en) * 2011-06-24 2012-12-25 Nextmaterials S R L CORRUGATED CARDBOARD FILTERS TREATED AND HAVING IMPROVED ANTIBACTERIAL EFFECTIVENESS AS WELL AS METHOD FOR THEIR IMPLEMENTATION, WITHOUT POTENTIALLY HARMFUL SUBSTANCES

Also Published As

Publication number Publication date
BE869638A (en) 1978-12-01
NL7808294A (en) 1980-02-12
GB2026567B (en) 1982-10-13

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732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee