admin 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
What is the tensile strength of paper? The tensile strength is the maximum stress to break a strip of paper sheet. It is one of the most important basic physical properties of paper and paperboard. The tensile strength is different basis on fiber direction. Since the fiber orientation is dissimilar between machine direction (MD) and … Read more
What is the tear strength of paper? The tear strength of paper means the resistance of a paper sheet to tearing force that it is subjected to. It is another important basic physical property of paper and paperboard. It is measured in both machine direction (MD) & cross direction (CD) and expressed as mN (mili … Read more
The caliper or thickness is one of the important basic physical properties of paper and paperboard. It is depends on refined stock, category of fiber, dryer temperature, load on press section and calendars, moister content, filler etc for a given basis weight. Thickness is related to bulk or dense of paper. Uniform caliper or thickness … Read more
The basis weight or grammage is basic physical property of paper and paperboard. The Basis weight of paper is calculating by the weight per unit area. It is mainly expressed as GSM (grams per square meter) and pounds per ream (500 sheets) of a specific size. It is also expressed in kg/m2, pounds per 1000 … Read more
The Canadian Standard Freeness is worldwide used for determination of the drainability of a dilute pulp suspensions of wet section in the paper machine. The rate of drainage is stated in terms of freeness. The freeness of pulp, as well as drainage rate is the measurable index of the effectiveness of refining process because it … Read more
The pulp freeness tester or slowness tester are extremely sensitive apparatus while applied effectively. Freeness of pulp is a measure of precisely how rapidly water can drain from a diluted fiber furnishes suspension. Drainage rate is related to the surface conditions and swelling of the fibers. On many occasions there is a correlation between freeness … Read more