Filter media for air filters and method for manufacturing the same

Abstract

The purpose of this disclosure is to provide an air filter material that has a high PF value and sufficient rigidity for practical use. [Solution] The filter material for an air filter according to the present disclosure is a filter material for an air filter that includes a wet nonwoven fabric, wherein the wet nonwoven fabric mainly contains glass fibers as a fiber component, the wet nonwoven fabric contains 0.5 to 15.0% by mass of starch relative to the mass of the fibers constituting the wet nonwoven fabric, and the amylose content of the starch is 20% or more.

Claims

1. A filter material for air filters, including a wet nonwoven fabric, The aforementioned wet nonwoven fabric mainly contains glass fibers as its fiber component, The wet-laid nonwoven fabric contains 0.5 to 15.0% by mass of starch relative to the mass of the fibers constituting the wet-laid nonwoven fabric. A filter material for air filters, characterized in that the amylose content of the starch is 20% or more.

2. The aforementioned wet nonwoven fabric is characterized in that it contains 80% by mass or more of glass fibers as a fiber component, as described in claim 1.

3. A dispersion step to obtain a slurry by dispersing glass fiber-containing fibers and starch powder in water, A papermaking process to obtain a wet sheet by forming the slurry into a sheet using a wet papermaking method, The process includes a drying step of heating the wet sheet to melt and bond the starch and obtain a dry sheet, The slurry contains 0.5 to 15.0% by mass of the starch relative to the mass of the fibers. The amylose content of the aforementioned starch is 20% or more. A method for manufacturing an air filter material, characterized in that the dry sheet is a wet nonwoven fabric mainly composed of glass fibers as its fiber component.

4. A dispersion process to obtain a slurry by dispersing glass fiber-containing fibers in water, A papermaking process to obtain a wet sheet by forming the slurry into a sheet using a wet papermaking method, The aforementioned wet sheet is subjected to an external application step in which an aqueous solution of starch is applied by spraying or impregnation, The process includes a drying step of heating the wet sheet to which the starch has been added externally to melt and bond the starch, thereby obtaining a dry sheet. The wet sheet to which the starch has been added externally contains 0.5 to 15.0% by mass of the starch relative to the mass of the fibers. The amylose content of the aforementioned starch is 20% or more. A method for manufacturing an air filter material, characterized in that the dry sheet is a wet nonwoven fabric mainly composed of glass fibers as its fiber component.

5. The method for producing a filter material for an air filter according to claim 3 or 4, characterized in that the starch is ground starch.

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