Controlling deposits on paper machine felts using cationic polymer and cationic surfactant mixture

A method of treating papermill felts which cycle between a sheet contact stage and a return stage and are used in processing pulp slurry into sheets to inhibit the deposit of sticky hydrophobic material on the felt comprising the step of:

• applying to the felt during the return stage an aqueous solution which is substantially free of anionic macromolecules and which contains (i) at least about 2 ppm of a cationic polymer which has a molecular weight between about 10,000 and about 300,000, and (ii) a water soluble surfactant having a molecular weight between about 200 and 800 and having the general formula ##STR11## wherein each R is independently selected from the group consisting of hydrogen, polyethylene oxide groups, polypropylene oxide groups, alkyl groups having between about 1 and 22 carbon atoms, aryl groups, and aralkyl groups, at least one of said R groups being an alkyl group having at least about 8 carbon atoms, and wherein X.sup.- is an anion, or l/n of an n-valent anion;
• the weight ratio of surfactant to polymer being between about 50:1 to 1.1;
• said surfactant being applied to the felt in an amount effective to inhibit build-up of deposits derived from said cationic polymer;
• and said cationic polymer being applied at an effective rate between about 0.002 and 0.5 grams per minute per square meter of felt such that the cationic polymer and the surfactant interact with the hydrophobic material so that it substantially loses its tendency to adhere to the felt.

A method of controlling the deposit of adhesive material on papermill felts in a papermaking system where recycled fibers account for at least about 10 percent of the fibers in the system, and where the felts cycle between a sheet contact stage and a return stage and are used to process pulp slurry containing both anionic macromolecules and adhesive material into sheets, the method comprising the step of:

• contacting the felt during the return stage with an aqueous solution which is substantially free of anionic macromolecules and contains (i) at least about 2 ppm of a cationic polymer which has a molecular weight between about 10,000 and about 3,000,000 and (ii) a water soluble surfactant having a molecular weight between about 200 and 800 and having a general formula ##STR12## wherein each R is independently selected from the group consisting of hydrogen, polyethylene oxide groups, polypropylene oxide groups, alkyl groups having between about 1 and 22 carbon atoms, aryl groups, and aralkyl groups, at least one of said R groups being an alkyl group having at least about 8 carbon atoms, and wherein X.sup.- is an anion, or l/n of an n-valent anion;
• said surfactant being applied to the felt in an amount effective to inhibit build-up of deposits derived from said cationic polymer;
• and said cationic polymer and surfactant being applied in a weight ratio of surfactant to polymer from about 10:1 to about 1:1, and interacting with the anionic macromolecules and adhesive materials to form products which can be easily removed from the felt.