| 摘要 |
<p>Cardboard for the outer layer of corrugated cardboard is prepared from a chemical pulp, or a semi-chemical pulp based on hard and soft woods, and a sulphated resinous pulp, with unsorted recovered paper, in the total mixt. ratio of between 2:1:2 and 2:2:1. In an example, the paper pulp is prepd. from a semi-chemical pulp comprising amixt. of 60% hardwood and 40% soft wood refined to 36 deg. SR by a neutral sulphate process and a process of fibrillation, an unbleached resinous sulphate pulp refined to 25 deg. SR, and an unsorted recovered paper refrined to 32 deg. SR in a ratio of 2:1:2. Among the hard woods, oak in particular represents a source of raw material which has not previously been used in papermaking. The invention provides an outlet for this wood in chemical and semi-chemical pulps in corrugated cardboard outer layers.</p> |
