Method of pulping waste pressure-sensitive adhesive paper
US5316621A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1992 |
| Grant date | May 31, 1994 |
| Priority date | — |
| Expiry date | Jun 18, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/64
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method of obtaining an excellent recycled pulp from waste pressure-sensitive adhesive paper which has previously been discarded. This method being characterized in that the waste paper is defiberized, then a defiberized suspension thereof is diluted, the diluted suspension is coarse screened by a screen having a slit width of below 0.5 mm, the pulp suspension after coarse screening is dewatered so as to have a solid matter consistency of 15 to 40% by weight, the dewatered stuff is mechanically agitated, the difference between the temperature of the stuff before the agitation and the temperature thereof after the agitation being below 12.degree. C., the obtained stuff is being diluted again, the diluted suspension is fine screened by a screen having a slit width of below 0.2 mm, the obtained accept is mixed with a surface active agent and subjected to flotation separation, the accept is cleaned by a cleaner for heavy foreign matters and/or a cleaner for light foreign matters, and then the accept being washed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.