| 摘要 |
<p>The present invention relates to method and apparatus for recovering and recycling paperboard for reuse as pulp, more particularly re-pulping and re-using waste paperboard resulting from various packaging and other paperboard coverting processes, which paperboard has been, in such processes, impregnated with wax or resin for the purpose of imparting wet strength and imperviousness to liquid. Essentially, the invention comprises process and apparatus for re-pulping the wax or resin impregnated paperboard in weak kraft black liquor produced in the conventional kraft cooking process and then washing the repulped material in a brown stock washer along with the virgin kraft pulp produced in the conventional cook, in order to clean the re-pulped material and recover and reuse the weak kraft black liquor used in the re-pulping process. When recovered by the process and apparatus of the present invention, such pulp can be uses in manufacture of corrugating medium and linerboard, for instance, for use in the manufacture of corrugated paperboard boxes. The process and apparatus have economic value in the recovery of paperboard pulp from the waste product not only as the inherent benefit of using a material otherwise wasted, but also because the process liquid, weak kraft black liquor, is itself a relatively inexpensive by-product of the original virgin kraft pulping process and thus provides a low cost treatment liquid for the process of the invention when temporarily diverted from the kraft recovery process for that purpose.</p> |
