| 摘要 |
Waste paper is deinked by pulping it in an aqueous liquor consisting of an alkali-metal hydroxide or carbonate, an anionic and a non-ionic surface-active agent and a protective colloid. The liquor may also contain an organic solvent. Examples of surface-active agents are: ethyleneoxide condensation products of alkyl-phenol, sodium dodecyl-benzene-sulphonate and polyoxyethylene ether of glyceryl triricinoleate. Protective colloids referred to include sodium carboxymethyl-cellulose, hydroxy-ethyl-cellulose, methyl-cellulose, methylethyl-cellulose, sodium cellulose sulphate, celluronic acid, starch ethers, casein, gliadin and soya proteins, sodium alginate, sodium polyacrylate, water dispensible lecithin and polyvinyl alcohol. The organic solvent may be trichloroethylene, perchloro-ethylene, methylene chloride, benzene, heptane petroleum ether, butyl alcohol, dipropyl ether, methylethyl ketone and ethyl acetate. The pulped material may be passed to a vibratory screen and concentrated thereby, the black liquor being used again either directly or with the addition of a proportion of fresh pulping liquor. The pulp may then be further washed by liquor or by fresh water and again concentrated by a vibratory screen. |
