Anti-microbial filter
The present invention relates to open-celled phenolic foam filters. In particular, the present invention relates to open-celled phenolic foam air filters for killing microbes present in air, and the use of said filters in antimicrobial air sanitation systems.
1 . A foam filter for filtering air comprising an open-celled phenolic foam, the open-celled phenolic foam having an accessible pore volume of from 0.5 m 3 to 0.96 m 3 per m 3 of foam, the open-celled phenolic foam comprising cells having an average cell size of from 0.5 mm to 7 mm; and the phenolic open-celled foam further comprising an antimicrobial agent, wherein the open-celled phenolic foam has a density of from 80 kg/m 3 to 800 kg/m 3 .
2 . A foam filter according to claim 1 , wherein the anti-microbial agent comprises a finely divided particulate solid having antimicrobial properties, or wherein the antimicrobial agent comprises a fiber-containing material with antimicrobial properties.
3 . A foam filter according to claim 1 , wherein the open-celled phenolic foam comprises cells having an average cell size of from 3 mm to 6 mm.
4 . A foam filter according to claim 1 , wherein the open-celled phenolic foam is rigid.
5 . A foam filter according to claim 1 , wherein the antimicrobial agent is present in the open-celled phenolic foam in an amount of from 5% by weight to 50% by weight of the foam material.
6 . A foam filter according to claim 1 , wherein the antimicrobial agent comprises a finely divided particulate solid having antimicrobial properties with a particle size of from 0.2 to 800 μm.
7 . A foam filter according to claim 1 , wherein the antimicrobial agent is an antibacterial agent, an antiviral agent, or a combination thereof.
8 . A foam filter according to claim 1 , wherein the antimicrobial agent comprises metal particles or fibers, wherein the metal comprises copper, titanium, silver, aluminium, cobalt, zinc, zirconium, molybdenum, tin or lead.
9 . A foam filter according to claim 1 , wherein at least a portion of the antimicrobial agent is present at a surface of the open-celled phenolic foam.
10 . A laminated filter structure comprising a foam filter according to claim 1 , and at least one layer of additional material in contact with at least one surface of the foam filter, wherein the at least one layer of additional material is bonded to the at least one surface of the foam filter, wherein:
(i) the at least one layer of additional material forms a portion of an outer surface of the structure, wherein the at least one layer of additional material does not cover the entirety of the at least one surface of the foam filter such that a portion of the at least one surface of the foam filter is exposed as a portion of the outer surface of the structure; or
(ii) the at least one layer of additional material comprises at least one aperture extending therethrough between the at least one surface of the foam filter and an outer surface of the at least one layer of additional material, wherein the outer surface of the at least one layer of additional material forms the outer surface of the structure.
11 . A laminated filter structure according to claim 10 , wherein the at least one layer of additional material comprises a plurality of apertures therein, wherein the plurality of apertures extend through the at least one layer of additional material between the at least one surface of the foam filter and an outer surface of the at least one layer of additional material.
12 . A laminated filter structure according to claim 10 , wherein a further layer of additional material is bonded to an opposing surface of the foam filter, such that the foam filter is sandwiched between the layers of additional material.
13 . A laminated filter structure according to claim 12 , wherein the at least one skin of sheet-form material comprises a thermoset material.
14 . A laminated filter structure according to claim 10 , wherein the at least one layer of additional material is mechanically keyed with the at least one surface of the foam filter, and wherein the additional material extends into the cells of the open-celled phenolic foam.
15 . A laminated filter structure according to claim 10 , wherein the laminated filter structure is obtained or obtainable by a curing process comprising the steps of: providing at least one layer of additional material; providing a foam filter; and pressing the at least one layer of additional material to the foam filter; and wherein gas and/or vapour can be displaced from the pressing region through the foam filter.
16 . A laminated filter structure according to claim 10 , wherein the foam filter comprises one or more grooves, channels, hollows or indentations so as to improve the flow of air through the laminated filter structure; and/or
wherein the at least one layer of additional material comprises one or more grooves, channels, hollows or indentations within its outer surface, such that an outer surface of the structure comprises one or more grooves, channels or indentations therein.
17 . A laminated filter panel according to claim 10 , wherein the at least one layer of additional material comprises an anti-microbial coating on its outer surface, such that the antimicrobial coating is disposed upon a portion of the outer surface of the filter structure.
18 . A system for the sanitization of air, wherein the system comprises:
(i) a chamber comprising one or more foam filters according to claim 1 , or laminated filter structures according to claim 10 within a chamber, wherein the one or more foam filters or one or more laminated filter structures are in fluid communication with an interior of the chamber;
(ii) one or more conduits configured for drawing air from an interior of the chamber, through the one or more foam filters or one or more laminated filter structures and into the one or more conduits.
19 . A system according to claim 18 , wherein the one or more foam filters or one or more filter structures are a component of at least one member of a group comprising: one or more walls of the chamber; one or more doors of the chamber, the floor or ceiling of the chamber, furniture within the chamber, and structural features.
20 . A foam filter according to claim 1 , wherein at least 50% of the cells present in the open-celled phenolic foam have a cell size of from 3 mm to 6 mm.