Chlorination bleaching is the second stage of the pulp bleaching process. It is the cheapest bleaching agent for eliminating lignin. Elemental chlorine (EC) reacts selectively with the non carbohydrate compounds. It is another significant delignification process. It ruptures the lignin bonds and make important amount of chlorinated organic compounds. All most all the products of … Read more
There are different types of paper such as Printing and Writing Papers, Tissue, Newsprint, Containerboard, Kraft Paper, and Paperboard. Paper towels are under category of tissue paper. After toilet paper, it is the most purchased tissue product by consumers. The basic raw material of paper towels is wood fiber. The fiber may be virgin or … Read more
Oxygen Delignification is one of the most significant and well proven pulp bleaching process for ECF (elemental chlorine free) and TCF (total chlorine free) bleached pulp production. It is the first stage of the bleaching process; in this case oxygen and alkali are used to eliminate a portion of the residual lignin in the pulp … Read more
Kraft pulping process is the most used pulping process in the world. In this process lignin goes into the reactions with the cooking liquor chemicals and split into fragment. These fragments dissolved with the solution and wood disintegrates into fiber. During the kraft pulping process about 80 percent of lignin, 50 percent of hemicelluloses and … Read more
Lignin is an aromatic complex polymer of monolignols (aromatic alcohols) which is found in plant cell walls. Later than cellulose, lignin is the most abundant natural polymer in the planet. It is not composed of carbohydrate monomers whereas the rest of polymers found in plant cell walls are composed of carbohydrate monomers for example cellulose. … Read more
Globally, there are several bleaching sequences are shown in different pulp mills to achieve the bleaching action. Different chemicals are used in each stage usually with washing between two stages to removes products. The preference of bleaching sequences depends on many things such as pulp categories, environment issue, operating cost, product quality of final bleached … Read more
The objective of pulp bleaching is to produce white pulp. Unbleached pulps are not suitable for manufacturing of high grade of white paper. Since all the processing pulp brightness is very low, especially Kraft pulp. The sulfite pulping process produces comparatively bright chemical pulps, while the others pulping process such as kraft, soda and semichemical … Read more
Screening equipment is the important operational system for pulp processing. After separation of the black liquor from the fiber in the washing section the pulp contains coarser fibers, foreign matter and dirt as like pieces of bark, digester brick, cement etc. Hence this unwanted and troublesome matter should be removed to produce first quality pulp. … Read more
There are different methods are available for pulp washing such as rotary vacuum washer, rotary pressure washer, pressure and atmospheric diffusion washers, horizontal belt washer and dilution/extraction equipment. Among them the rotary vacuum washer method is well-known to paper makers for long times. This method of pulp washing is employing a series of rotary vacuum … Read more
Sulfate or Kraft pulp is one of the chemical pulping processes. It is manufactured by alkaline method. Kraft pulping process is the dominating pulp manufacturing process in the world. Today this process is most widely used with a production of 70-80% of the total Pulp. Raw material: Although soft wood are mostly used but any … Read more