GRC 211 Lecture Notes - Lecture 2: Hydrogen Peroxide, Rosin, Starch
28 May 2017
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Document Summary
Paper produced has low strength + yellowish color. Mechanical pulping + high temperature/pressure to break the bond of fibers. Process: wood chips treated with chemicals, goes through mechanical pulping process, yield: 85-90% Chemicals used to dissolve lignin + separate fiber. Does not damage fiber; stronger than mechanical pulping process. Does not work well with some softwoods. Easier to recover chemicals = no pollution. Yield (highest to lowest): mechanical pulp, thermo-mechanical pulp (tmp), Strength (highest to lowest): chemical pulp, chemical-thermal-mechanical pulp (ctmp), chemical-thermal-mechanical pulp (ctmp), chemical pulp thermo-mechanical pulp (tmp), mechanical pulp. Mechanical pulp: high yield, better paper uniformity, bulkier paper (more fiber), more resilient paper. Process that completely separates and modifies fibers. Fibrillation: delamination of cell wall (flattens fibers + makes small hairs stick out of fiber; makes resulting paper stronger because more surface area of fiber to be in contact with each other) Purpose: enhance properties of paper / introduce special properties to paper.
