Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – With chemical or physical modification of liberated fiber
Patent
1993-07-02
1995-03-21
Chin, Peter
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
With chemical or physical modification of liberated fiber
81161, 81164, 8184, 8195, 162158, 1621576, 162182, D21H 1120
Patent
active
053992407
ABSTRACT:
The invention is a method of making a wet formed, sheeted, readily reslurriable sheeted crosslinked cellulose and the products made by the method. Crosslinked wood pulp fibers tend to be quite brittle. If crosslinked while in sheeted form, the sheets cannot be readily defibered, either in a wet or dry state, without serious fiber degradation. The sheet products of the present invention can be easily redispersed or repulped in water without significant fiber breakage. The present products are made by including within the sheet, while still in wet form, a debonding or softening agent which is preferably added before the latent crosslinking reactant. Most preferably the debonder is added prior to the headbox of a paper machine and the crosslinking reactant is applied near the end of the forming wire or at the press section. The treated sheet is dried conventionally. Crosslinking may occur entirely during drying or during a period of additional heating, usually at a temperature in excess of 100.degree. C. for a short period of time. Conventional debonding agents and crosslinking reactants are suitable. The softening agent apparently reduces or prevents adhesive bonding between adjacent fibers caused by polymer formation external to the fibers under reaction conditions.
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Graef Peter A.
Hunter Frank R.
Chin Peter
Weyerhaeuser Company
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