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PAPER MANUFACURING PROCESS |
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REPULPING
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The process of dispersing the dry and compacted pulp fibers
(UKP) and secondary fibers (waste paper) in a water slush, slurry or suspension
through the mechanical actions of hydrapulpers running simultaneously
or alternately at range 3 to 5% consistency. An average beating time of
40 minutes.
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COARSE SCREENING
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A stage screening process of removing dirt particles
from 3-5 to 5% stock consistency through perforated and slotted type screen
basket respectively. The lightweight particles move up to the top reject
outlet while heavy debris is rejected at the bottom. The stock goes out
tangentially at the middle part of the screen.
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FINE CLEANING
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" Combination of four stage forward cleaning system
in combination with reverse cleaning at the final stream.
" Subsequently, the concentrated light rejects from the forward cleaners such as Styrofoam and stickies are separated at high efficiency in the core cleaners or reverse cleaners. |
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FINE SCREENING
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This is a three stage slot fine screening system which
removes rejects such as knots, entanglements, shives, strings, foam particles,
stickies and plastics coatings the utilization of vertical screen and
minisorters. The rejects removed from this stage are then fed to oscillating
wire for dewatering.
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HOT DISPERSION
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The hot dispersion system includes dewatering of the
pulp up to 30% consistency, heating, of the stock to melt stock, size
and bitumen and fine dispersion of all impurities so that contaminants
are unseen to the naked eye. (for liner grades only)
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REFINING
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The process of cutting or brushing the pulp fibers
at 4-5% stock consistency through mechanical actions of series of refiners
for purpose of achieving certain "freeness" targets for specific
paper grades.
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SHEET FORAMATION
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A hydrostatic process of forming the sheet of paper
from an endless mat of finely woven fibers consistency and continuously
flowing from pressurized head box into a high speed running fourdrinier
wire. About 20-30% of the water is removed here.
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PRESSING
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Pressing is the process which involves compression
of the sheet to take out water from the paper and to achieve good web
consolidation. Through the utilization of two-shoe type Flexonip pressing
in series, higher sheet dryness, better runnability and reduction in costs
is achieved. About 25-40% of the water is removed here.
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DRYING
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After pressing, moisture is further reduced by evaporation
through the introduction of steam in the dryer cylinders. The heat absorbed
by the dryer cylinders is then transferred to the fiber to evaporate the
moisture in the paper. A final dryness of 93-94% is attained after this
section.
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CALENDERING
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Calendaring is the process where the paper passes through
calendar rolls to achieve the desired smoothness and thickness of the
paper.
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REELING
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A process of winding or wrapping the sheet of paper
around a reel drum up to a certain specified diameter. (called jumbo roll)
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REWINDING
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This is the last activity in the paper making processes
where the jumbo roll of the finished paper is trimmed, rewound and strapped
into specified sizes according to the customer's requirements.
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