kraft a4 paper manufacturers

A4 Paper Manufacturers , A4 paper suppliers, A4 copy paper manufacturers 
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iteness. Whiteness is the ability a4 paper a4 paper after exposure to light overall reflected light level is a4 paper. In most cases, a4 paper caused by the action of light and heat of white decreased, and the strength is reduced, often referred to as "yellowing." Yellowing is one of the characteristics of aging a4 paper. (E) a4 paper variant of. a4 paper wet deformation and permanent deformation produced in the wet and dry conditions. deformability a4 paper to print adversely. Generally, a4 paper and paper deformation rate of the fiber type and paper production related. Rag pulp paper grades deformation small, large chemical wood pulp paper create deformation unbleached chemical pulp is more easily deformed than bleached chemical pulp. Second, the aging of a4 paper archives in archives and use the process, archive a4 paper gradually undergoing irreversible change in appearance, structure and properties of the various aspects, known as "aging" or "worsening." a4 paper aging embodied in three aspects, namely, color, strength decreases and changes in chemical properties. 1. File a4 paper acidic hydrolysis of cellulose. A4 paper archives department at all levels of the majority of the existing archives containing acid. Acid is the most important factor causing Archives a4 paper aging and even chalking. Because the archives acid catalyzed hydrolysis of cellulose degradation. Archives acids from: ① in the paper production process, such as mechanical papermaking cooking liquid, bleach, especially rosin sizing a4 paper brought to the acid; ② the acid gas in the air and dust in the acidic substance is archives adsorbed; ③ writing, printing on the archival material a4 paper writing an acid; ④ after the file mildew, mold will secrete organic acids such as oxalic acid and citric acid; ⑤ cellulose, hemi-cellulose, especially wood Su produce acidic substances in the oxidation or hydrolysis. 2. File a4 paper enzymatic degradation of cellulose. When records storage relative humidity, the archive is easy to mildew. Archives a4 paper yellow after mildew, stains little mechanical strength sharp decline, seriously damaged the archives life. This metamorphism archives, mainly secreted by fungal cells in the metabolic processes caused by various enzymes, the most important is the cellulase. Cellulase is a specialized hydrolysis of cellulose into the insoluble biocatalyst soluble sugars. Cellulase catalytic intense, it is possible within three months of the a4 paper c