Filter material.

摘要

The invention relates to filter material, in particular for producing tea bags, coffee bags or coffee filters, comprising an at least two-layer nonwoven web fabric or the like, at least one layer produced on a papermaking machine comprising natural fibres and one layer comprising synthetic fibres and which are shaped flat and arranged one above the other. According to the invention, the second layer comprising synthetic fibres contains a multiplicity of individual synthetic fibres which are applied in the heated state to the first layer comprising natural fibres and are fused both together and to the fibres of the first layer. The filter material has, in particular, the advantage that by applying the individual synthetic fibres to a layer of natural fibres a great number of pores or channels of the layer made of natural fibres is covered or sealed. It thus shows an extremely low particle loss since only a small number of continuous pores are present, an interlaced and enclosed filter material being created essentially by the arrangement of individual synthetic fibres on the layer of natural fibres which are furthermore fused with this layer.