Dry sheet-like filtering material for liquid depth filtration
US5114537A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1990 |
| Grant date | May 19, 1992 |
| Priority date | — |
| Expiry date | Oct 23, 2010 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H27/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A dry sheet-like filtering material for use in liquid depth filtration and a method for making the filtering material are disclosed. The filtering material is prepared from cellulose ester fibrils having a surface area of at least 5 square meters per gram and cellulose fibers which have been beaten. The degree of beating to which the cellulose fibers are subjected and the amount of cellulose acetate fibrils mixed with the cellulose fibers can be controlled to affect the retention and flow rate characteristics of the filtering material. The filtering material is produced by preparing slurries of the cellulose ester fibrils and the cellulose fibers, beating at least the cellulose fibers, mixing the slurries, depositing the mixed slurry on a porous surface which permits the drainage of water from the deposited fibrous structure, removing the water whereby the fibrous structure is formed into a filter sheet, and drying and cutting the filter sheet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.