Filter media including silicone and/or wax additive(s)
A method of improving filtration efficiency of a fibrous nonwoven filter media comprises providing a filter media and incorporating in the filter media one or more additives selected from the group consisting of silicone additives, wax additives, and mixtures thereof. The filter media comprises glass fibers, polymer fibers, and optionally binder. Inclusion of silicone and/or wax additive(s) in a filter media has surprisingly been found to increase filtration efficiency, for example, by 10-15%.
1. A method of improving filtration efficiency of a fibrous nonwoven filter media, the method comprising:
providing a filter media comprising:
40-60 weight % glass fibers, total fibers basis; and
40-60 weight % polymer fibers, total fibers basis; and
incorporating in the filter media one or more additives selected from the group consisting of silicone additives, wax additives, and mixtures thereof.
2. The method of claim 1 , wherein incorporating in the filter media the one or more additives comprises applying the one or more additives to the filter media.
3. The method of claim 2 , wherein the one or more additives are present in an amount of about 1-15 weight %, final filter basis.
4. The method of claim 1 , wherein the filter media is self supporting.
5. The method of claim 1 , wherein the filter media meets at least MERV 7 specifications.
6. The method of claim 1 , wherein the filter media further comprises binder.
7. The method of claim 6 , wherein:
incorporating in the filter media the one or more additives comprises applying the one or more additives to the filter media; and
the one or more additives are present in an amount of about 5 weight %, final filter basis.
8. The method of claim 6 , wherein incorporating in the filter media the one or more additives comprises including the one or more additives in the binder.
9. The method of claim 8 , wherein the one or more additives are present in an amount of about 5-25 weight %, binder solids basis.
10. The method of claim 8 , wherein the one or more additives are present in an amount of about 15 weight %, binder solids basis.
11. The method of claim 6 , wherein the filter media further comprises:
cellulosic fibers.
12. The method of claim 1 , wherein the polymer fibers comprise crimped polymer fibers.
13. The method of claim 1 , wherein:
the one or more additives are present in an amount of about 2 weight %, final filter basis.
14. The method of claim 1 , wherein the polymer fibers comprise bi-component polyethylene/polypropylene fibers.
15. The filter media of claim 1 , wherein the polymer fibers comprise crimped polyester fibers.
16. The filter media of claim 15 , wherein the polymer fibers comprise crimped polyethylene terephthalate fibers.
17. The filter media of claim 6 , wherein the binder comprises a modified urea-formaldehyde binder or an acrylic latex binder.
18. The filter media of claim 6 , wherein the binder comprises an acrylic latex having a glass transition temperature of greater that about 20° C.
19. The filter media of claim 1 , wherein the filter media comprises:
40-60 weight % H ½″ glass fibers, total fibers basis; and
40-60 weight % ¼″ 1.5 denier polyethylene terephthalate fibers, total fibers basis; and
wherein the filter media further comprises acrylic binder.
20. The filter media of claim 1 , wherein the filter media comprises:
40-60 weight % glass fibers;
40-60 weight % bi-component polyethylene/polypropylene fibers.