Almost 1/3rd of the paper production in the country comes from mills using agricultural residues. These mills are smaller in size compared to mills using forest-based raw materials. This is a drawback to these mills in becoming more cost effective. Also, many of these mills do not have chemical recovery plant and have to treat large quantities of effluent before discharge.

One of the major disadvantages of the alkaline process is that considerable portion of polysaccharides, predominantly hemi-celluloses are degraded to a host of acids, thereby consuming about two thirds of alkali charged for pulping. "Surecook" has been developed not only to reduce the pulping chemical cost but also to have a more environmental friendly approach and manufacture paper with better strength.

"Surecook" is capable of substituting 20-40% of the caustic by only 2-4% of it, in pulping of agricultural residues. It is formulated to overcome drawback of caustic soda i.e. hydrolysis of cellulose fibers, which results in breaking of the chain and loss of strength. Broad specifications of this chemical is as below:

GENERAL RECOMMENDED RECIPE

Following recipe is generally recommended for manufacture of brown grade pulp from agricultural residues. It may vary from mill to mill depending upon individual mill requirement and pulping conditions.

Cellulose chains existing at the fiber surface contain hydroxyl group that participate in fiber to fiber bonding during manufacture of paper. The hydroxyl groups on the fiber surface as well as within the fiber wall, interact strongly with water giving swelling to fiber. The process of swelling due to water is very slow when compared to chemical processes. A strong mechanical process i.e. refining is any way required to have a fibrillation, better swelling and hence better bonding.

Pulping processes produce both chemical and structural changes in fiber. Structurally, dissolution of lignin and hemi-celluloses due to chemicals, results in more of internal fiber wall surface becoming accessible to water during papermaking. Pulping also results in a number of chemical modifications to the cell wall constituents. Cellulose may get degraded by hydrolysis/ oxidation reactions, which result in chains having reduced molecular weight and containing carbonyl/carboxyl groups in their chemical structure.

Caustic soda is the main chemical used in pulping. Though it appears to be an inexpensive inorganic alkali available for such treatments, it has drawbacks that are well known but unavoidable.

"Surecook" facilitates the penetration of alkali into the cell wall of the wood-water interface. Once the alkali enters the lignin deposits, it clears the same and accelerates the process of lignin solubilization. This also reduces the contact time of alkali with lignin thereby preventing de-polymerization of cellulose. "Surecook" increases the anionicity of the system, which prevents de-polymerization of lignin molecules that is one of the side reactions in the delignification process.