Process and apparatus for expediting the mercerization of alkali cellulose
US4275195A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1979 |
| Grant date | Jun 23, 1981 |
| Priority date | — |
| Expiry date | May 24, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08B1/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process and apparatus for making alkali cellulose having a desired predetermined degree of polymerization in which cellulose is steeped in an alkali hydroxide bath, generally 17-25% sodium hydroxide, and then passed through an RF treatment chamber where it is subjected to an RF energy field, to produce a controlled depolymerization thereof. Upon emergence from the steeping bath, the cellulose passes to an excess solution removing means, such as one or a series of pairs of nip rolls where the excess solution is expressed from the cellulose and the amount of absorbed alkali is controlled. Preferably, the excess solution is recovered and returned to the steeping baths. A second, lower concentration, steep bath may follow the RF treatment chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.