Polyurethane foam surgical dressing
US3978855A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1975 |
| Grant date | Sep 7, 1976 |
| Priority date | — |
| Expiry date | Jan 17, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/268
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The invention is directed to an open celled polyurethane foam article, which initially is generally non-absorbent, the surface of which is subsequently rendered absorbent by decreasing the average pore cell size to a critical range while preferably also simultaneously or subsequently achieving a critical range of a wetting agent in such surface. This can be accomplished in either of two ways. The first method is to permanently collapse the cells in the surface region of the original foam so that the concentration of any residual wetting agents initially present in the structure increases in the compressed surface region, thus rendering said surface more readily absorbent. For a surgical dressing, the surface cells should be permanently but only partially collapsed to substantially less than the original size to form a microporous skin. According to the second method substantially all residual wetting agents which may be present in the original foam material are extracted from the polyurethane either before or after forming the microporous skin surface. Preferably, the extraction comes after formation of the skin so that a controlled amount of a desired wetting agent(s) can then be …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.