Abstract: An improved method of brown stock washing is disclosed. A nonionic surfactant in combination with a polyelectrolyte dispersant, and preferably a solvent, are utilized in the washing step in the pulping of virgin cellulosic fiber. The methods of the invention provide for the enhanced removal and recovery of cooking chemicals and organics from the pulp.

Abstract: The method of substantially removing and dispersing resinous or waxy contaminants from contaminant-containing secondary fiber during repulping, is disclosed. The method includes combining the contaminant-containing secondary fiber in an aqueous repulping medium with a substituted oxyethylene glycol nonionic surfactant, and a water soluble, low molecular weight polyelectrolyte dispersant, at an elevated temperature.

Abstract: Washing methods of deinking secondary cellulose fiber (i.e., removing unwanted non-cellulose materials therefrom) are disclosed. These washing methods (as opposed to flotation methods) generally involve deinking the fiber with surface active agent (surfactant).The present invention utilizes a single foam-suppressing surface active agent consisting essentially ofR--(Ar)--(OC.sub.2 H.sub.4)m--(OC.sub.3 H.sub.6)n--Y;wherein R represents a monovalent higher aliphatic group containing from 6 to 24 carbon atoms,Ar represents an aromatic residue,--(OC.sub.2 H.sub.4)m--being a poly(ethylene oxide) chain,--(OC.sub.3 H.sub.6)n--being a poly(propylene oxide) chain;m is about 6 to about 15,n is about 12 to about 48,m:n is less than 1, andY is selected from the group consisting of hydroxyl and benzyl ether.The present washing method of deinking reduces or eliminates objectionable foam, potentially provides energy savings yet maintains or improves the quality of the deinked fiber.

Abstract: Diaryl urethanes made by capping poly (oxyalkylene) diols with monoisocyanates are characterized by a desirable hydrophobe/hydrophile balance typically evidenced by low cloud points, the ability to form micelles in aqueous media, the ability to reduce stable foam, and the ability to be taken up and retained by paper fibers, the low foaming or de-foaming capability of these compounds is useful in machine dishwashing detergents and additives, which hydrophobe/hydrophile balance is typically obtained through a combination of oxyethylene and oxypropylene units or blocks in the oxyalkylene chain.