| 摘要 |
Paper pulp for the productions of paper, paper board, &c. is sized by adding to an acid furnish, starch, rosin, or rosin-size a water-soluble or water-dispersible urea-formaldehyde condensation product, and an alkali metal metasilicate or sesquisilicate, and precipitating as with aluminium or iron sulphate or chloride. The starch may be added as wheat, corn, rice, or potato fluor. The pH value of the pulp may be between 4.2 and 5.8 during beating, and the size may be added as an aqueous dispersion of gel globules. The constituents of the size dispersion may be mixed in various orders, in water, or dry. An example specifies Kraft pulp coloured with carbon black made into boards on a cylinder machine and dried under pressure at 195-200 DEG F. for 8 to 12 hours, the slow drying insolubilizing the resin to form a tough, rubbery condensation product. A dry mixture of, e.g. 57 parts of urea-formaldehyde, 65 of starch, 32 of resin, and 52 of sodium metasilicate pentahydrate may be prepared as a precipitable sizing composition. Specification 568,352, [Group VIII], is referred to.ALSO:Paper pulp for the production of paper, paper board, &c., is sized by adding to an acid furnish, starch, rosin or rosin size, a water-soluble or water-dispersible urea-formaldehyde condensation product, and an alkali metal metasilicate or sesquisilicate, and precipitating as with aluminium or iron sulphate or chloride. The starch may be added as wheat, corn, rice or potato flour. The pH value of the pulp may be between 4.2 and 5.8 during beating, and the size may be added as an aqueous dispersion of gel globules. The constituents of the size dispersion may be mixed in various orders, in water, or dry. An example specifies Kraft pulp coloured with carbon black made into boards on a cylinder machine and dried under pressure at 195-200 DEG F. for 8 to 12 hours, the slow drying insolubilizing the resin to form a tough, rubbery condensation product. A dry mixture of e.g. 57 parts of urea-formaldehyde, 65 of starch, 32 of resin, and 52 of sodium metasilicate pentahydrate may be prepared as a precipitable sizing composition. Specification 568,352 is referred to. |
