The use of paper though is being minimized yet its use cannot be closed entirely. So, instead of using paper that is creating problems in the environment. A completely bleached Kraft pulp is utilized to make a high quality paper.
The type and the nature of stuff being used by the common person in their daily life are contributing the increasing effects of global warming.
The use of paper though is being minimized yet its use cannot be closed entirely.
So, instead of using paper that is creating problems in the environment, why not opt for environment friendly paper, which shall only help people in leading hygienic and clean life and also help each one to put their step forward in minimizing the adverse effects of the wrong practice of materials.
1. Cooking
The wood chips from the harvested tress after being collected are fed to the equipment known as digesters. These wood chips are then impregnated with the cookery liquors, which may either be black or white liquor.
This process of digestion takes a long time and that too at a very high temperature of about 130 to 180 degrees Celsius. Such maintained circumstances degrade the lignin and hemi cellulose into pieces that are effortlessly mixable with strong alkaline liquid.
This process gives a hard thick pulp which is brown colored and after the pulp is collected it is cleaned by washing. During this process of cooking, the nucleophilic bonds are broken.
2. Recovery or concentration
During this procedure, the black liquor is concentrated that contains 20 – 30 % of the solids.
However it may be concentrated to 80% to give larger residuals. On further reactions of some salts of sodium by a complete method, it leads to the formation of green liquor.
The apparatus used for such processes are big boilers that generate steam and in advanced Kraft paper production this is a rich resource of steam to produce electricity.
3. Blowing
By using air under reduced pressure of atmosphere, the processed wooden chips are blown.
This process releases lot of energy in the form of steam again which can be used to produce electricity by leading them to run turbines, which also relieves a lot of volatile and evaporable material which may or may not be condensed depending upon region to region.
4. Separating / Screening
Under this process, pulping machines play a vital a role the brown pulp produced initially is screened from the filth and a clean Kraft pulp is obtained.
This is finished with the help of a range of sieves by using the centrifugal force as a form for separation.
5. Cleaning
During this process, various equipment’s wash the Kraft pulp so obtained. This Kraft pulp undergoes a variety of cleaning procedure.
The type of equipment used can be named on the basis of their mode of clearing.
The cleaning equipment may be designed to use atmospheric pressure; vacuum and many more designs are available.
6. Bleaching
The Kraft pulp obtained is then bleached to get brilliance and fairness in the pulp using various chemicals.
A completely bleached Kraft pulp is utilized to make high-quality paper.
The Kraft paper manufactured using such a process is environmental as it has more strength as compared to other kinds of paper.
Its own by products can be utilized as a supply of energy also, it gives a lot of other residuals like turpentine oil and many other products that can be reprocessed.
