EP0614620A2
Expired / Lapsed
EP
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Extruded filtration materials
Assignee: British American Tobacco Investments Ltd
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Filing: 1994-03-08
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Granted: —
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Expires: 2014-03-08
Abstract
Abstract An extruded filtration material which is degradable and comprises either a plastics material or an inorganic material having a melting point above the operating temperature, a polysaccharide expansion medium, a binder and water. These ingredients are fed to an extruder and subjected to an extrusion process which involves a pressure reduction, upon extrusion from the exit die, of up to about 70 bars so that swelling of the extrudate occurs to give a cellular structure. When exposed to the natural weather conditions, tobacco smoke filter elements comprising such material degrade without leaving a fused amalgamation of plastics or inorganic material. <IMAGE>
Inventors
- 👤 John Lawson Beven
- 👤 Paul David Case
- 👤 Martin Coleman
- 👤 Colin Campbell Greig
- 👤 Peter Rex White
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 07:45
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/06; A24D3/16; A24D3/08
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
44 words
An extruded filtration material comprising plastics material, a water-soluble polysaccharide expansion medium, a binder and water, the melting point of the plastics material being greater than the operating temperature at the operating conditions of the extrusion process, wherein the extruded filtration material is degradable.
Claim 2
Dependent Claim
17 words
An extruded filtration material according to Claim 1, wherein said filtration material is tobacco smoke filtration material.
Claim 3
Dependent Claim
29 words
An extruded filtration material according to Claim 1 or 2, wherein said plastics material is one or more of the group comprised of cellulose acetate, polypropylene, polyethylene or polystyrene.
Claim 4
Dependent Claim
16 words
An extruded filtration material according to Claim 3, wherein said cellulose acetate is cellulose acetate flake.
Claim 5
Dependent Claim
22 words
An extruded filter action according to any one of Claims 1, 2, 3 or 4, wherein said polysaccharide expansion medium is starch.
Claim 6
Dependent Claim
33 words
An extruded filtration material according to Claim 5, wherein said starch is one or more of maize starch, a starch having a higher proportion of amylose than amylopectin or a chemically modified starch.
Claim 7
Dependent Claim
31 words
An extruded filtration material according to any one of the preceding claims, wherein the binder is one or more of the group comprising a cellulosic binder, a pectin or an alginate.
Claim 8
Dependent Claim
26 words
An extruded filtration material according to any one of the preceding claims, wherein said filtration material comprises 0-90% plastics material, 0-100% polysaccharide material and 0-50% binder.
Claim 9
Dependent Claim
18 words
An extruded filtration material according to Claim 8, wherein said filtration material further comprises 0-25% of a plasticiser.
Claim 10
Dependent Claim
25 words
An extruded filtration material according to Claim 9, wherein the plasticiser is one or more of the group comprising glycerol, a sugar or a humectant.
Claim 11
Dependent Claim
65 words
A process of making an extruded filtration material, wherein plastics material, water-soluble polysaccharide expansion medium, binder and water are mixed together, and extruded through the exit orifice of an extruder die, the plastics material being selected so that the melting point thereof is above the operating temperature of the extrusion process at any particular operating pressure, wherein the extruded product is cellular and is degradable.
Claim 12
Dependent Claim
118 words
A process according to Claim 11, wherein said plastics material comprises 0-90% of one or more of the group comprising cellulose acetate, polyethylene, polypropylene and polystyrene, said polysaccharide material comprises 0-100% of one or more of the group comprising maize starch, starch having a higher proportion of amylose rather than amylopectin, rice starch, tapioca starch and chemically modified starch, said binder comprises 0-50% of one or more of the group comprising cellulosic binders, pectins and alginates, all of the materials being on a dry weight basis of the materials fed to the extruder, and wherein 1-35% by weight of water is fed to the extruder, as a weight basis of the materials plus water fed to the extruder.
Claim 13
Dependent Claim
61 words
A process according to Claim 12, wherein said plastics material comprises about 80% by weight, said polysaccharide material comprises about 15% by weight and the binder material comprises about 5% by weight of the dry materials fed to the extruder, and said water is in the range of 8-20% by weight of the total material, including water, fed to the extruder.
Claim 14
Dependent Claim
71 words
A process according to Claim 12, wherein said plastics material is present within the range of 55-75%, said polysaccharide material is present within the range of 20-35% and said binder material is present within the range of 5-15% on a dry weight basis of the materials fed to the extruder, and said water is within the range of 8-20% by weight of the total material, including water, fed to the extruder.
Claim 15
Dependent Claim
68 words
A process according to Claim 12, wherein said plastics material is within the range of 65-95%, said polysaccharide material is within the range of 1-35% and said binder material is within the range of 1-15% on a dry weight basis of the materials fed to the extruder, and said water is within the range of 8-15% by weight of the total material, including water, fed to the extruder.
Claim 16
Dependent Claim
72 words
A process according to Claim 12, wherein said plastics material is present within the range of 0-50%, said polysaccharide material is present within the range of 50-100% and the binder material is present within the range of 0-50%, by weight of the dry materials fed to the extruder, and said water is present within the range of 5 to 50% by weight of the total materials, including water, fed to the extruder.
Claim 17
Dependent Claim
28 words
A process according to any one of Claims 11-16, wherein said plastics material is any one or more of the group comprising cellulose acetate, polyethylene, polypropylene and polystyrene.
Claim 18
Dependent Claim
41 words
A process according to any one of Claims 11-17, wherein said polysaccharide material is any one or more of the group comprising maize starch, starch having a higher proportion of amylose than amylopectin, rice starch, tapioca starch and chemically modified starches.
Claim 19
Dependent Claim
26 words
A process according to any one of Claims 11-18, wherein said binder material is one or more of the group comprising cellulosic binders, pectins and alginates.
Claim 20
Dependent Claim
42 words
A process according to any one of Claims 11-19, wherein said filtration material further comprises 0-25% of a plasticiser selected from the group comprising glycerol, a sugar or a humectant, on a dry weight basis of the materials fed to the extruder.
Claim 21
Dependent Claim
68 words
A degradable smoking article comprising a degradable smoking material enwrapped in degradable wrapping material and a degradable filter comprising extruded filtration material enwrapped in degradable wrapping material, said filtration material comprising 0-90% plastics material, 0-100% water-soluble polysaccharide material and 0-50% binder material, all on a dry weight basis of the extruded filtration material and being produced by a process in accordance with any one of the Claims 11-20.
Claim 22
Dependent Claim
33 words
A tobacco smoke filter element comprising a rod of extruded filtration material, the rod of filtration material being degradable and being produced by a process in accordance with any one of Claims 11-21.
Claim 23
Dependent Claim
33 words
A tobacco smoke filter element according to Claim 22, wherein the filtration efficiency of the extruded filtration material is substantially constant over a pressure drop of 30-120mm W.G. per 20mm length of rod.
Claim 24
Dependent Claim
22 words
An extruded filtration material comprising inorganic material, a water-soluble polysaccharide expansion medium, a binder and water, wherein the filtration material is degradable.
Claim 25
Dependent Claim
69 words
A process of making an extruded filtration material according to Claim 24, wherein inorganic material, water-soluble polysaccharide expansion medium, binder and water are mixed together, and extruded through the exit orifice of an extruder die, the inorganic material being selected so that the melting point thereof is above the operating temperature of the extrusion process at any particular operating pressure, wherein the extruded product is cellular and is degradable.
Claim 26
Dependent Claim
43 words
An extruded filtration material according to Claim 24, wherein said inorganic material is comprised of one or more of the group consisting of vermiculite, alumina, aluminium hydroxide, carbon, chalk, Metaspheres 50 (Trade Name), aluminosilicates, such as Garolite (Trade Name), and Trihyde (Trade Name).
Claim 27
Dependent Claim
40 words
An extruded filtration material according to Claim 25 or 26, wherein said inorganic filler material comprises 60-85% by weight, said polysaccharide expansion medium comprises 5-20% by weight, said binder comprises 5-25% by weight, of dry materials fed to the extruder.
Claim 28
Dependent Claim
21 words
An extruded filtration material according to Claim 27, wherein plasticiser in an amount of 3-10% is further supplied to said extruder.
References Cited (Backward Citations)
No citation records indexed.
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