公开(公告)号：DE3000367A1

公开(公告)日：1981-07-09

申请号：DE3000367

申请日：1980-01-07

Applicant: BASF AG

Inventor： JUNG DIETMAR DIPL CHEM DR ,  WISTUBA ECKEHARDT DIPL CHEM DR ,  AUHORN WERNER ING GRAD ,  PFOHL SIGBERG DIPL CHEM DR

IPC: D21H11/14 ,  D21H17/37 ,  D21H3/02 ,  D21H3/58

Abstract: Prodn. of paper with improved dry strength on paper machines with highly confined or entirely enclosed water circulation involves adding 0.05-5 wt.%, w.r.t. the wt. of the dry fibres, of an agent (I) improving the dry strength to pulp contg. min. 25% waste paper fibres, which is adjusted to pH 6.5-8.5. The pulp pref. consists of pulped and bleached or deinked waste paper. (I) is an acrylamide polymer. (I) is effective, in spite of the (almost) closed water circulation. The paper is suitable for writing, printing and packaging purposes, toilet paper, paper towels etc.

公开(公告)号：DE2938510A1

公开(公告)日：1981-04-23

申请号：DE2938510

申请日：1979-09-24

Applicant: BASF AG

Inventor： HORN DIETER DIPL CHEM DR ,  DITTER WALTER ,  AUHORN WERNER ING GRAD

IPC: C02F1/52 ,  C02F1/54 ,  B01D43/00 ,  D21C9/18 ,  D21D3/00

Abstract: Flocculation of negatively charged solid particles in aq. systems is affected by adding a cationic polyelectrolyte (I). The process is carried out by (a) adding 40-100% of the amt. of (I) required for optimum flocculation to 25-75% of the total amt. of the aq. system, (b) homogeneously dispersing the added (I) in the aq. system, (c) combining the mixt. with the remaining 25-75% of the aq. system, and (d) adding the remaining 0-60% of (I). The process is esp. applicable to fibre and filler slurries in papermaking machines, but can also be applied to sewage, waste waters, etc. Compared with adding the whole amt. of (I) to the whole aq. system, the process increases the flocculation rate and/or the degree of flocculation.