Controlled-porosity, calendered spunbonded/melt blown laminates
US5308691A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 1993 |
| Grant date | May 3, 1994 |
| Priority date | — |
| Expiry date | Oct 4, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/66
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Controlled porosity composite sheets comprising a melt-blown polypropylene fiber web having a spunbonded polypropylene fiber sheet laminated to at least one side thereof are made by calendering an assembly of the component webs in such a manner that, when a two-layer composite sheet is made, the web of melt-blown fibers is in contact with a metal roll heated to 140.degree.-170.degree. C. operating against an unheated resilient roll; and, when a three-layer composite sheet is made, the spunbonded web in contact with the heated metal roll has a dtex per fiber value of less than 6. These composite sheets have a Gurley-Hill porosity of about 5-75 seconds, excellent mechanical and tear strengths, high water vapor penetration rate, and low liquid water permeability. They are particularly suitable for making housewrap sheets and sheets for sterile packaging. In the sterile packaging field, they are significantly better than medical paper used for the same purpose.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.