Abstract: Paper, board and cardboard are produced from paper stocks which contain tacky impurities by the addition of surfactants and cationic polymers having a charge density of at least 1.5 meq/g (measured at pH 7) and a molar mass Mw of the cationic polymers of at least 15,000 and drainage of the paper stocks with fixation of the tacky impurities in the paper produced.

Abstract: In antifoams based on oil-in-water emulsions, the oil phase of the emulsions contains(a) a C.sub.12 -C.sub.26 -alcohol, a distillation residue which is obtainable in the preparation of alcohols having a relatively large number of carbon atoms by the oxo process or by the Ziegler process and which may furthermore be oxyalkylated and/or(b) a fatty acid ester of a C.sub.12 -C.sub.22 -carboxylic acid with a monohydric to trihydric C.sub.1 -C.sub.18 -alcohol and, if required,(c) a hydrocarbon having a boiling point above 200.degree. C. or a fatty acid of 12 to 22 carbon atoms,accounts for from 5 to 50% by weight of the emulsion and has a mean particle size of less than 25 .mu.m, and from 5 to 50% by weight of components (a) and (b) of the oil phase are replaced by(d) one or more compounds which melt at above 70.degree. C. and are selected from the group consisting of the fatty alcohols of not less than 28 carbon atoms, the esters of a C.sub.1 -C.sub.

Abstract: The measuring arrangement consists of successive workstations which comprise a stock of paper samples, a balance, a mechanized moistening means for the sample and a blotting means, likewise mechanized, for the moistened sample. An industrial robot controllable by a program and equipped with a gripping apparatus is provided for carrying out the measurement. This arrangement determines the liquid absorbed by paper using the Cobb method and permits the measuring method to be carried out in a fully mechanized manner.

Abstract: Individual air permeably sheetlike structures are efficiently lifted from a pile by a vacuum lifter and deposited again at a processing station, the pile including as an alternate interlayer a sheet of air impermeable material.

Abstract: The maximum amounts of the retention-influencing variable stock components which can be added are determined as a function of a predetermined degree of flocculation and typical values of the stock suspension with the aid of a mathematical relationship, and control signals for metering retention aids are derived from the amounts so that the greatest possible retention can be achieved without exceeding a set-point for the degree of flocculation.

Abstract: Stabilized water-containing sodium dithionite formulations which have been rendered alkaline have the consistency of a pumpable paste. They additionally contain readily soluble sodium salts and/or potassium salts which are inert to sodium dithionite and whose water-solubility at 20.degree. C. exceeds 500 g/l. These salts are present in the aqueous phase in an amount of not less than 200 g/l. The pastes are useful reducing agents.

Abstract: In antifoams based on oil-in-water emulsions, the oil phase of the emulsion contains(a) C.sub.12 -C.sub.26 -alcohols, distillation residues obtained in the preparation of alcohols by an oxosynthesis or by the Ziegler process and/or(b) fatty acid esters of C.sub.12 -C.sub.22 -carboxylic acids with monohydric, dihydric or trihydric C.sub.1 -C.sub.18 -alcohols, with or without(c) a hydrocarbon having a boiling point above 200.degree. C. or fatty acids of 12 to 22 carbon atoms,constitutes from 15 to 60% by weight of the emulsion and has a mean droplet size of from 0.5 to 15 .mu.m. The emulsions are stabilized by the addition of from 0.05 to 0.5% by weight, based on the total emulsion, of a high molecular weight water-soluble homopolymer or copolymer of acrylic acid, methacrylic acid, acrylamide or methacrylamide.

Abstract: Process for the production of water-soluble auxiliaries for the papermaking industry by reacting(a) 1 part by weight of a polyamidoamine obtained by condensing 1 mole of a dicarboxylic acid having from 4 to 10 carbon atoms with from 0.8 to 1.4 moles of a polyalkylene polyamine having from 3 to 10 alkyleneamine units and containing up to 8 ethyleneimine units per basic nitrogen atom with (b) 0.1 to 4 parts by weight of an .alpha.,.omega.-dichloro polyalkylene oxide obtained by reacting a polyalkylene oxide having from 8 to 100 alkylene oxide units with a compound selected from the group consisting of a thionyl chloride and phosgene and then cleaving the reaction products by heating them to a temperature of from 70.degree. to 150.degree. C. in the presence of a tertiary amine as catalyst,as crosslinking agent, at a temperature above 20.degree. C.

Abstract: A process for the preparation of water-soluble polymeric crosslinking agents by a two-stage reaction of di-secondary diamines with epichlorohydrin and/or dichlorohydrin, wherein, in the first stage, di-secondary diamines are condensed with epichlorohydrin and/or dichlorohydrin in a molar ratio of from 1:0.5 to 1:1 at a pH of from 9 to 12, and in the second stage the condensates obtained in the first stage are reacted with additional epichlorohydrin and/or dichlorohydrin at a pH of from 4 to 8.5. The water-soluble condensates thus obtained are crosslinking agents for polyamines, polyamidoamines, ethyleneimine-modified polyamidoamines and polyether-amines. The crosslinking reaction gives water-soluble condensates, which possess a high cation activity and may be used as retention aids, drainage aids and flocculants in the manufacture of paper.

Abstract: Mixtures of high molecular weight polyacrylamides in the form of a water-in-oil polymer dispersion and containing in the inner phase from 99.99 to 95% w/w of a cationic polyacrylamide and from 0.01 to 5% w/w of an anionic polyacrylamide or from 99.99 to 95% w/w of an anionic polyacrylamide and from 0.01 to 5% w/w of a cationic polyacrylamide, all percentages being based on the total amount of polymer. The said polymer mixtures are particularly effective retention aids and flocculants and are preferably used in the manufacture of paper as pulp additives.