Unisol - B & T | Specification detail
Role of Unisol in Technology of Paper Making:
The basic material of paper is cellulose which occur in the form of fibers in
many vegetable tissues. The pulp fibers in aqueous suspension subjected to
mechanical treatment like beating and refining . Refining is splitting and
cutting of the fibers whereas beating is fibrillation and hydration of the
fibers., Beating increases bursting strength, tensile strength , folding
endurance, smoothness and hardness but decreases tearing resistance, opacity
dimensional stability and bulk of paper.
At the beater stage materials are added known as " wet End additives "
Like mineral fillers ( China Clay, Calcium Carbonate, Titanium Dioxide ) sizing
agents ( Rosin or synthetic agents ) Binders ,Resins, Slimicides, Antifoaming
agents and dyestuffs.
Unisol has an important place in the beater additives which increases the
strength of the sheet. After mechanical treatment the stock is diluted and
cleaned, treated with alum and enters the head box where main part of the water
is removed by filtration.
The Wet sheet passes through series of presses and then on to the steam heated
dryers drums. The dryer section contains size press used for improving the
surface properties like writing, erasing and strength quality of the sheet.
Unisol is the most important surface sizing agent. In the size press the dilute
starch solution is applied to the surface of the paper where it cements the
fibers to the body of the paper increasing the surface strength.
After drying the paper role passes on the calendar stack to improve the
smoothness and finish of the paper. The third important application of Unisol in
the paper industry is in coating where it is used as a binding agent in a
pigment layer applied to the paper which improves the printability and finish of
In Nut shell :
Unisol plays vital role in paper making as " wet end additive " for increasing
the strength of the sheet. In surface sizing improving bursting, folding
endurance and tensile strength supplementing the beating operations . As a
Coating Agent " for binding the pigment layer applied on the paper for improving