Mechanical wood pulp

Braun-saLz, n, any of certain brown dyes. -schliff, m. (Paper) steamed mechanical wood pulp, brown wood pulp, braunschwarz, a, brown-black, very dark brown. 

Dampf-heizrohr, n. steam (heating) pipe, -heizung, /. steam heating, -holzschliff, m. steamed mechanical wood pulp, -hiillet /. steam jacket vaporous envelope. 

In mechanical wood pulping, the glycolignin remains undissolved, whereas some of the hemilignins are dissolved, their solubilities in water being the main limiting factor. It is thus possible that some of the hemilignins are also responsible for the yellowing of mechanical pulp. 

Since unbleached cellulose and mechanical wood pulp have a distinctly negative charge due to the acid lignin groups, products of opposite polarity, i.e., basic or cationic, can interact with the fiber directly by ionic bonding. 

Staining a surface, either chemically or optically, helps differentiate parts of a composite surface and identify the various phases. A variety of stains are available for diverse surfaces. Mineral sections can be etched with hydrofluoric acid then stained with Na3Co(N02)e to differentiate quartz (unetched), feldspars (etched but unstained), and potassium feldspars (etched and stained yellow). Paper surfaces can be stained with Harzberg stain (Calkin, 1934) to differentiate lignified cellulose e.g., straw, manilla, and mechanical wood pulp [yellow or yellow green]) from purified cellulose e.g., chemical wood pulp, bleached straw, or manilla [blue or blue violet]) or pure cellulose e.g., cotton or linen [wine red]). Isings (1961) selectively stains unsaturated elastomers with osmium tetroxide. 

Uses Antifoam for paper and cellulose industries, chemical industries, coatings, printing inks, plastics, ceramic glazes, waste water treatment, fiberboard, mechanical wood pulp, paper coatings, straw pulp, tissue papers, water paper, screenings, wood pulp mfg. emulsion paints, gloss emulsion paints, wallpaper inks... 

The production of paper and paperboard in 1995 was 278 X 10 mt worldwide. Roughly a quarter of the fiber material used derives from mechanical or semi-mechanical wood pulp, another quarter from the use of waste paper, while the rest is bleached or unbleached chemical pulp. 

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