Electrostatically-effective air filter material
AssigneeFirma Carl Freudenberg
InventorsKarl-Heinz Morweiser, Klaus Veeser, Harald Stini
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Abstract
An air filter material for intercepting dust is disclosed. The material is free of lubricants and antistatic agents, and consists of a blend of (I) polyolefin fibers and (II) polyacrylonitrile fibers that are geometrically stable. The fibers (I) are two-component polypropylene/polyethylene fibers of the core/jacket or side-by-side type, and fibers (II) are halogen-free. The fiber blend is washed during the manufacturing process after they are first combined.
Claims16
An electrostatically effective air filter material, consisting of a blend of:
- type (I) polyolefin fibers that are two-component polypropylene/polyethylene fibers of the core/jacket or side-by-side type;
- and
- type (II) halogen-free polyacrylonitrile fibers,
- wherein the filter material is geometrically stable and wherein the fibers are free of lubricants and antistatic agents.
A method for filtering out solid or liquid aerosols, comprising the steps of:
- mixing together
- (I) a quantity of polyolefin fibers that are two-component polypropylene/polyethylene fibers of the core/jacket or side-by-side type with
- (II) a quantity of halogen-free polyacrylonitrile fibers;
- washing the resulting mixture of fibers so that it is free of lubricants and antistatic agents;
- forming the mixture of fibers into a non-woven fabric by carding;
- needling the fabric and electrostatically charging the fabric;
- and
- forming the fabric into a shape appropriate for use as a filter.
A process for manufacturing an electrostatically effective air filter material which is free of lubricants and antistatic agents comprising the steps of:
- mixing together
- (I) a quantity of heterofilament polyolefin fibers that are two-component polypropylene/polyethylene fibers of the core/jacket or side-by-side type with
- (II) a quantity of halogen-free polyacrylonitrile fibers;
- at a weight ratio between 30:70 to 80:20 for the type I fibers with respect to the type II fibers;
- washing the resulting mixture of fibers so that it is free of lubricants and antistatic agents;
- drying the fibers;
- forming the mixture of fibers into a non-woven fabric by carding;
- needling and stiffening the fabric;
- and
- thermally activating the heterofilament fibers.
Dependencies are inferred from the claim text.