CTMP-process
US6458245B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1996 |
| Grant date | Oct 1, 2002 |
| Priority date | — |
| Expiry date | Dec 31, 2019 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/163
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An absorbent, chemithermomechanical pulp produced from lignocellulosic material with a wood yield above 88%, a low resin content <0.15%, a long fibre content above 70%, a short fibre content below 10% and a shive content below 3. The method for producing the pulp comprises the steps of impregnating, preheating, defibering, and washing the material. The impregnation and preheating of the chips are effected in one and the same vessel over a combined time period of a most 2 minutes, particularly at most 1 minute, preferably at most 0.5 minutes; using a warm impregnating liquid having a temperature of at least 100° C., suitably at least 130° C. and preferably having essentially the same temperature as in the preheating process; and preheating the chips at a temperature of 150-175°C., preferably 160-170° C. Defibering is carried out with an energy input which is at most half of the energy input required for defibering when the preheating and defibering are carried out at 135° C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.