VIB Tech Dictionary

A term descriptive of darkening of the intended shade of paper by excessive calendering or by calendering wet paper.

Defects caused by creasing or cutting of the web of paper during calendering due to wrinkles in the web.

(1) Defects in paper in the form of indented spots. They are caused by foreign matter adhering to the calender rolls.
(2) Marks on paper caused by material sticking to a calender roll.

(1) A series of highly polished rolls which are used to control paper smoothness and caliper by adjustments to the load on the rolls.
(2) Steel rolls at the dry end of a paper machine which smooth and level the sheet of paper.

Dark lines in paper, parallel to the grain. Caused by uneven pressing and drying before calendering.

(1) The thickness of a sheet of paper, expressed in thousandths of an inch (mills or points). Sometimes referred to as bulk.
(2) The thickness of a sheet measured under specific conditions. It is usually expressed in thousandths of an inch (points or mils).

A means of supporting the machine by beams across and on the rear to hold the front side suspended (without support) for felt and fabric changes.

Any expenditure involving a depreciable piece of equipment.

A series of ropes which travel over pulleys and carry the paper thread trough the dryer sections.

Refers to caustic soda (sodium hydroxide).

An alkaline chemical used as a makeup chemical in our cooking liquor. It is also used for pH control in our bleach system, demineralizer, and softening at the filtered water plant. In the paper mill it is used for boiling out paper machine equipment and system. It is highly dangerous.

Low pressure created by the suction of a pump causing a boiling action as the liquid begins to vaporize creating bubbles of vapor.

The fibrous material remaining after the non-fibrous components of wood have been removed by the pulping and bleaching operation; used in making paper.

Pulp obtained by cooking wood with solutions of various chemicals.
The principal chemical processes are the sulfite, sulfate (kraft), and soda processes.

The main roll of the Sym Press II press section.

An excellent grade of clay used with similar materials as filler for paper.

A term applied to paper machines with rotating knives which cut pulpwood logs to chips about 1" square and 1/8" thick.

Chopped wood prepared for cooking to produce pulp.

Greenish-yellow gas. It is highly toxic and irritating. It is used as a bleaching agent and for bacteria control and for a water treatment.

Yellow gas used in solution as a bleaching agent. Highly toxic and explosive.

The addition of free chlorine to water to control the bacteria population. Also, one of the pulp bleaching stages.

Marks in paper produced by the clamps which hold it in position for guillotine trimming.

A large settling basin used as the first -treatment of the mill effluent. The solids or underflow is pumped to the sludge pond while the overflow goes to the aeration pond.

A filler - see filler.

Vessels which remove dirt and foreign material from the paper stock by centrifugal action.

White water that has been filtered through a save-all and is relatively free of fines and fillers.

A number by which an employee is listed on company records and which is used to keep records of that employee's hours worked, etc.

A fiber structure which gives uniform density in a sheet of paper. The opposite of a cloudy or uneven formation.

A term indicating unevenness or irregular formation in look-through of paper. It is another term for wild formation.

White water which contains appreciable amounts of filler and fines.

(1) A term applied to various types of fabrics used on the paper machine.
(2) A term applied to paper-machine felts and Fourdrinier wires.

A term applied to various grades of paper used for industrial purposes as opposed to grades used for cultural purposes.
They can be bleached or unbleached, usually range from a basis weight of 18 pounds or more (24 x 36-500), and are frequently colored or printed or both. Grades falling into this category include wrapping papers, bag papers, adhesive tapes, building papers, heavy-duty envelopes, towels, etc.

Coated board produced from virgin fiber or recycled board, used for producing high-quality cartons for food packaging.

Coated papers are high-quality magazine papers. They are produced with on-line and off-line coaters for use in printing presses.

The coating mixture in suspension or slurry form which is applied to the surface of the paper or paperboard in the coating process. It includes the pigments, adhesives, dyestuffs, modifiers, and the liquid medium (usually water) required to carry and apply the components to the paper.

Any paper used as a base paper for coating. The type of paper depends on its ultimate use.

The shade of white that a particular grade of paper is.

The amount of specified material in a given volume of solution.

The water formed when steam cools and condenses.

Allowing a paper sample to remain in a controlled humidity atmosphere until its moisture content remains constant.

(1) The percentage of bone dry fiber found in a solution.
(2) The percentage, by weight, of air-dry (or oven dry) fibrous material in a stock or stock suspension. It is also called density or concentration.

A desk-Iike table or structure containing control elements such as start and stop buttons for operating equipment.

A remotely located box used to operate equipment.

The CONTROL STATION^ECS governs the control of the pneumatic actuators. Each actuator is controlled with an I/P-converter with a control signal of 40 – 200 kPa (6 – 30 PSI). Setpoints are sent from the Integrated Process Station (IPS) using measurement system data.

A device used to restrict the flow of a fluid to control the flow to a specified rate, normally operated by means of automatic equipment.

A process of converting the original paper into another one with different characteristics.

A mechanical device, such as a belt, screw, chain, or bucket elevator used to transport material.

Uncoated paper in woodfree or wood-containing varieties. It can be white or multicolored and has a DIN A4 and DIN A3 format or legal or letter size.

Defects in sheet generally caused by uneven caliper.

Chemical action on metal, forming rust, scale, pits, etc., wears away the metal and damages equipment.

A paperboard used by corrugating plants to form the corrugated or fluted component for making corrugated combined board, corrugated wrapping, and the like. It is usually made from chemical or semi chemical wood pulps, straw or reclaimed paper stock on cylinder or fourdrinier machines in nominal grade weights of 26 Ib./M sg. ft. and approximately nine points thickness although heavier weights are sometimes used.

(1) A large hollow roll with holes drilled over the entire shell. The wire passes over it and water is removed from the sheet by vacuum applied to the roll.
(2) Roll used to separate wet paper web from the "wire".

Rolls of paper which may be used in dispensers on the counters of retail stores, generally 0 inches in diameter in various widths.

The connection of the drive motor with the drive shaft.

Mechanical device used in moving large and heavy objects such as reels of paper and press rolls.

The process of crowding a sheet of paper on a roll using a doctor, thereby producing an effect simulating crepe. Semi-creped or primary creped or machine-creped paper is produced by a doctor blade on the paper machine (usually located on the last press or first drier, and, sometimes, for special effects, about halfway along the drier section). The percentage of crepe is usually low. Secondary creped or water-creped paper is produced as a converting operation, the paper being moistened and passed over a roll equipped with a doctor. Extremely high percentages of crepe can be achieved by this process. Modifications of it permit cross- directional creping and diagonal creping, sometimes called an all-directional stretch. Dry creping is a process in which a dry sheet is removed from a Yankee drier by a doctor blade.

(1) The direction of the paper at right angles to the machine direction.
(2) The dimension in a piece of paper at right angles to the direction of the grain.

The difference in diameter between the middle and ends of a press roll or calender roll necessary to allow for deflection so that the nip pressure will be uniform over the full width of the press or calender. The increase in diameter of the middle over the ends expressed in thousands of an inch is called the crown of the roll.

Cathode Ray Tube used to display data from a computer.

A term applied to paper, the formation of which has been broken, by running it too wet under the dandy roll, through the presses, or with too much moisture through the calender.

A defect in machine-made papers caused by excessive pressure or moisture at the dandy, couch, or press rolls, characterized by a mottled or cloudy appearance. Crushing by excessive pressure in the calenders is called blackening.

Unsaleable off-grade paper.

(1) The tendency of paper to bend to one side of the sheet under humidity changes due to uneven evaporation of absorption of water from side to side of the sheet.
(2) Tendency of a sheet of paper to coil or roll up at the edges.
Usually caused by changes in weather or faulty drying on the paper machine.

Steamshower to control on-line curl in both cross and machine direction.

A machine which cuts rolls of paper into predetermined sheet sizes. The sheets are then cut to final size on a guillotine trimmer.

CV factor denotes the flow characteristics of control valves in terms of the flow coefficient Cv. The flow coefficient Cv is based on the imperial units system and is defined as: "the flow of water through a valve at 60 °F in US gallon/minute at a pressure drop of 1 lb/in²"
The flow coefficient Cv is commonly used in the US.

One of the principal types of papermaking machines, characterized by the use of wire-covered cylinders or molds on which a web is formed. These cylinders are partially immersed and rotated in vats containing a dilute stock suspension. The pulp fibers are formed into a sheet on the mold as the water drains through and passes out at the ends of the cylinders. The wet sheet is couched off the cylinder onto a felt, which is held against the cylinder by a couch roll. A cylinder machine may consist of one or several cylinders, each supplied with the same or different kinds of stock. In the case of a multi-cylinder machine, the webs are successively couched one upon the other before entering the press section. This permits wide variation in thickness or weight of the finished sheet, as well as a variation in the kind of stock used for the different layers of the sheet. The press section and the dry end of the machine are essentially the same as those of other types of machines.