| 摘要 |
<p>A laminate of thermoplastic film materials exhibiting throughgoing porosity and comprising plies A and B, A having an inner surface A1 partly in contact with B and an outer surface A2, and B having an inner surface BI partly in contact with A and an outer surface B2, A and B consisting of continuous material except for a multitude of perforations in each ply, whereby essentially no perforation in A corresponds directly to a perforation in B, the lamination between A and B on surfaces A1 and B1 being a) through a coextruded lower melting lamination layer on A and/or B and b) established in such discontinuous manner that there is formed a channel system between A1 and B1 connecting the majority of the perforations in A each with at least one of the perforations in B, and connecting the majority of the perforations in B each with at least one of the perforations in A is provided in addition to a process and apparatus for producing such a laminate.</p> |
