Biology 2217B Study Guide - Final Guide: Cai Lun, Papermaking, Softwood
13 Apr 2018
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Papyrus(monocot): not true paper due to way formed, from liquid suspension of fibres into mat. Paper: word derive from papyrus: ts"ai lun chinese (cid:272)ourt offi(cid:272)ial in(cid:448)ent paper. Paper-making in europe linen/cotton rags main source, manual labour: veggie fibre (cellulose) wet easily in water, form bond when dried. Cotton fibers: expensive, only for things require durability. Bast fibers from flax plant (stem: hemp/jute are other forms. Grass fibers: wheat straw, absorb water readily, made from crush stalks of sugar cane. Wood fibers: 95% paper made (deciduous hardwood eg. oak, maple, coniferous soft eg. pine, spruce (produce stronger pulp) True paper: made from pulp-slurry fibers in water. Mechanized process: machine invent by fourdrinier: increase paper production dramatically. Wood chemistry: 45-60% cellulose-desirable for paper, white, fibrous, 15-30% lignin-poor paper properties cause yellowing. Wood structure: softwood: strong but rough paper, hardwood: smooth, soft, less strong. Pulping processes: 1: mechanical pulping: wood ground, washed, screen, rolled, use: low quality paper-newsprint.
