Controlled porosity composite sheets comprising a melt-blown polypropylene fiber web (20) having a spunbonded polypropylene fibersheet (10) laminated to at least one side thereof are made by calendering an assembly of the component webs in such a manner that, when atwo-layer composite sheet is made, the web of melt-blown fibers is in contact with a metal roll (1) heated to 140-170 °C operating againstan unheated resilient roll (2) and, when a three-layer composite sheet is made, the spunbounded web in contact with the heated metal roll hasa dtex per fiber value of less than 6. These composite sheets have a Gurley-Hill porosity of about 5-75 seconds, excellent mechanical andtear strengths, high water vapor penetration rate, and low liquid water permeability. They are particularly suitable for making housewrapsheets and sheets for sterile packaging. In the sterile packaging field, they are significantly better than medical paper used for the samepurpose.
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