Pitch reduction on paper machine forming fabrics and press fabrics
AssigneeW. R. Grace & Co.-Conn.
InventorsEvan V. Rohlf, Fletcher Walley, Richard J. Wagner
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Abstract
A method for controlling or inhibiting the deposition of pitch derived from aqueous pulp suspensions having a neutral or cationic soluble charge onto paper machine equipment surfaces which contact the pulp, comprising a) contacting the pulp with an anionic polymer in an amount sufficient to maintain an anionic charge in the pulp and b) contacting the paper machine equipment surfaces with a cationic polymer in an amount sufficient to inhibit the deposition of pitch deposits thereon.
Claims17
A method for controlling or inhibiting the deposition of pitch, derived from an aqueous pulp suspension having a neutral or cationic soluble charge, onto paper machine equipment surfaces which contact the aqueous pulp suspension and wherein the pulp suspension is treated on the paper machine to form paper, comprising the steps of:
- a) contacting the aqueous pulp suspension with a water soluble anionic polymer or water soluble anionic surfactant in an amount sufficient to change the neutral or cationic soluble charge to an anionic soluble charge of at least -15 .mu.eq/l in the aqueous pulp suspension without negatively affecting the quality of the paper;
- and
- b) contacting the paper machine equipment surfaces which contact the aqueous pulp suspension with a water soluble cationic polymer, a water soluble cationic surfactant, or mixture thereof in an amount sufficient to inhibit the deposition of pitch deposits thereon, wherein the cationic polymer or surfactant has a charge density of at least 0.1 meq/g.
Dependencies are inferred from the claim text.