Dearborn Chemical Company Ltd.

David A Aston

Stewart N Paul

John E Waller

John K Hochu

John A Gray

A method for the control of pitch in paper making machine dryer fabrics or equipment which are not in continuous contact with process water comprising applying to the fabrics or equipment, a water-soluble or water-dispersible cationic polymer and a water-soluble or water dispersible anionic aromatic polymer.

Pitch control

A method is disclosed for treating papermill felts to inhibit the deposit of sticky material thereon. The method comprises applying an aqueous solution which contains at least about 2 ppm of a cationic polymer; which contains a water soluble cationic surfactant; the surfactant being applied in an amount effective to inhibit build-up of deposits derived from the cationic polymer. Cationic surfactants are preferred. Particular use is disclosed of water soluble surfactants which have a molecular weight between about 200 and 800 and having the general formula: ##STR1## 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 1/n of an n-valent anion. Compositions comprising said cationic polymers and said surfactants in a weight ratio of surfactant to cationic polymer of from about 50:1 to about 1:1 are disclosed as particularly useful for treating felts.

Controlling deposits on paper machine felts using cationic polymer and

Iron oxide deposits are removed from substrates by use of aqueous solution at approximately neutral pH containing a phosphonate (e.g., hydroxyethylidene diphosphonic acid), a reducing agent (e.g., sodium sulfite), and a corrosion inhibitor (e.g., benzotriazole). Optionally, a surfactant and dispersant may be included.

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David A Aston