| 摘要 |
The filter bag includes at least one support- and one fleece layer having a mean fiber diameter of 10-1000 nm, weight 0.5-2 g/m<2> and air permeability 1500-20,000 l/m<2> x s. At least one support layer has air permeability exceeding 70 l/m<2> x s, resistance to longitudinal rupture exceeds 20 N/15 mm (width of strip), and corresponding transverse resistance exceeds 10 N/15 mm. Preferred features: The nano fiber fleece is deposited directly onto the support material, forming a two-layer composite. I addition a reinforcement is deposited on the fleece, when forming the composite. The support material is a spun-bonded fleece fabric. Its weight is 10-100 g/m<2>. Its air permeability is 100-8000 l/m<2> x s. In a variant the reinforcement is a fleece, spun bonded, melt blown or dry laid. Further standardized, quantified specifications are provided for variants. The supp material forms the exterior, the reinforcement the next layer and the fleece the final layer, connected to it. Further possible variants of the structure are listed. All layers are impermeable to water. |
