al-quraish paper terminology

Paper Terminologies

De-Inking Cells

Before printed paper, such as office waste and newspapers, can be recycled the ink needs to be removed, otherwise it will be dispersed into the pulp and a dull grey paper would result. There are two main processes for de-inking waste paper - these are known as washing and flotation.


The waste paper is placed into a pulper with large quantities of water and broken down into a slurry. Contraries -such as staples - are removed using centrifugal screens. Most of the water containing the dispersed ink is drained through slots or screens that allow the dispersed ink particles through, without taking the pulp. Adhesive particles, known as 'stickies' are removed by fine screening


Again the waste is made into a slurry and contaminants removed. Special surfactant chemicals are added which makes a sticky froth on the top of the pulp. Air bubbles are blown through the pulp and these carry the inks to the surface. As the bubbles reach the top a foam layer is formed that traps the ink. The foam must be removed before the bubbles break or the ink will go back into the pulp. Because the ink is removed from the flotation machine in a concentrated form, the flotation system does not require a large water treatment plant


This is where the cellulose fibers pass through a refining process which is vital in the art of papermaking. Before refining, the fibers are stiff, inflexible and form few bonds. The stock is pumped through a conicle machine which consists of a series of revolving discs. The violent abrasive and bruising action has the effect of cutting, opening up and declustering the fibers and making the ends divide. This is called fibrillation. In this state, the fibers are pliable and have greater surface area, which significantly improves the fiber bonding. The properties of the paper are directly related to the refining process. Refining used to be called beating.

Mixing Chest

The stock passes to a blend chest where numerous chemicals can be added to obtain the required characteristics to the finished paper. Dyes are also added, as necessary, to color the paper. Dyes fix themselves to the cellulose fibers and are fast to light and water. Each grade of paper and board requires a very accurate blend of pulps and additives and the properties of the paper are continually monitored by computers during manufacture.

High Pressure Screens

Pressure screens are used to prepare paper fiber suspensions and, namely, to process the fibrous suspension in a wet screening. To do this, this type of pressure screen contains at least one wire that is provided with a multiplicity of openings. The fibers contained in the suspension are intended to move through the openings while the undesired solid components are rejected and guided out of the screen again. Pressure screens can also be used for fiber fractionation whereby the long fibers are concentrated in the overflow and the short fibers in the throughput. As a rule, round holes or slots are used as screen openings. In most cases, pressure screens of the type considered here are equipped with wire clearers, which are moved closely past the wire. Clogging of the screen openings is thus avoided in a manner known per se.


This is a drum-type machine which acts as a washer using gravity as the form of momentum. All fine fractions, including contaminants and excess liquid pass through the fabric or drum.| washed and thickened stock is couched from the drum. The main object of Thickner is to remove excess water from the pulp along with unwanted contaminents.