Filter sheet material and method of making same
First Claim
1. A process for making a filter sheet material which comprises mixing a paste of a powdered absorbent having a particle size of about 0.1 to 50 μ
- m with a solution or dispersion of a polymeric binding agent comprising at least one member selected from the group consisting of polyurethanes, polyacrylates, halogenated or halogen-free elastomers, fusible polyamides, fusible polyesters and fusible ethylenevinyl acetate copolymers thereby to form a composition, printing the composition on at least one surface of a porous textile sheet material in discrete areas to a height of about 0.05 to 1 mm and a width of about 0.1 to 5 mm, the discrete areas covering up to about 90% of the surface with unprinted areas separating the discrete printed areas, the powdered absorbent being applied in about 20 to 250 g/m2 and the polymeric agent being present in about 20 to 200% of the weight of the adsorbent, and drying the textile sheet material, the resulting filter sheet material having an air permeability under a 10 mm water column of about 50 to 5000 liters per square meter per second.
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Abstract
The invention relates to a filter sheet material composed of an air-permeable, flexible, especially textile supporting layer, on which there is imprinted in a certain pattern a mixture containing an adsorbent in powder form and a polymeric binding agent, the adsorbent covering up to 90% of the surface of the supporting layer. The invention furthermore relates to the use of such filter sheet materials with active carbon as adsorbent for protective clothing, and to the preparation of the material by rotary screen printing from a paste made of the powdered adsorbent and a dispersion of the polymeric binding agent.
111 Citations
13 Claims
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1. A process for making a filter sheet material which comprises mixing a paste of a powdered absorbent having a particle size of about 0.1 to 50 μ
- m with a solution or dispersion of a polymeric binding agent comprising at least one member selected from the group consisting of polyurethanes, polyacrylates, halogenated or halogen-free elastomers, fusible polyamides, fusible polyesters and fusible ethylenevinyl acetate copolymers thereby to form a composition, printing the composition on at least one surface of a porous textile sheet material in discrete areas to a height of about 0.05 to 1 mm and a width of about 0.1 to 5 mm, the discrete areas covering up to about 90% of the surface with unprinted areas separating the discrete printed areas, the powdered absorbent being applied in about 20 to 250 g/m2 and the polymeric agent being present in about 20 to 200% of the weight of the adsorbent, and drying the textile sheet material, the resulting filter sheet material having an air permeability under a 10 mm water column of about 50 to 5000 liters per square meter per second.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
Specification