VIB Tech Dictionary

Crushed or blackened streaks running in the machine direction. They are the result of crushing caused during pressing or calendering a sheet of paper having high moisture content areas.

A defect in paper caused by the dandy roll picking up fibers from the sheet or otherwise disturbing the sheet formation to leave thin spots or other imperfections.

(1) A roll placed on the fourdrinier to help reduce two sidedness of the sheet.
(2) A skeleton cylinder covered with a woven wire cloth, or with an arrangement of fine longitudinal wires, crossed at close intervals by heavier circumferential wires. The former structure produces wove and the latter laid paper. The dandy roll is one method of applying watermarks to paper while wet. It is positioned on the top of the wire in front of the couch roll.

The accumulation and storage of mill data in the mill's computer system.

A bar located on the underside of the winder. Used for sheet spreading to keep rolls from running together on the winder. Common name is spreader bar.

Motor driven by direct current.

Special papers for laminating chipboard surfaces in the furniture and construction industry. Décor paper is rotogravure color printed with a wide range of imitation wood graining, masonry textures or other patterns. Later the paper is impregnated with resin and pressed onto the chipboard surface.

(1) A term indicating the width of the web formed on the paper machine.
(2) The straps (deckle ruler) on the wet end of a paper machine which prevent the fibers from flowing over the sides and which determine the width of the web of paper which can be run on any given machine.

A surface-active chemical used to inhibit the production of and to kill foam.

A vessel which utilizes an ion exchange resin to chemically remove scale and sludge forming material from boiler feed water.

The weight per unit volume of a material, i.e., water has a weight of 8.33 Ibs./gallon, etc.

The units of division within the mill. Each is the responsibility of the designated department head.

Water introduced into a steam line to lower the superheat temperature and which reduces steam pressure.

Large pressure vessel in which wood chips are cooked to separate fibers from each other and from undesirable particles in the wood. To "blow the digester" means to release the pressure and empty the contents of the digester.

The difference in pressure between the inlet dryer steam pressure and the outlet condensate pressure, or the difference in pressure from the top dryers to the bottom dryers.

The Digital Hardware Station manages the flow through the digital valve blocks. Setpoints are sent from the Integrated Process Station using measurement system data.

The digital valve is used to control the amount of water of each control zone.
Each valve block has 6 solenoids. With the combination of the setpoints for the solenoids the water flow is controlled in 64 steps from minimum to maximum flow.

The addition of water to lower concentration.

That property of a sheet of paper which relates to the constancy of the dimensions in the machine and cross-machine directions under conditions of different relative humidity.

A fine paper especially designed for treatment with a light-sensitive coating. This paper then becomes the copy paper for diazo reproductions, such as Ozalid. The master for producing these copies can be on Nekoosa Master-Lucent.

The amount of foreign material expressed in parts per million found in a sheet of paper or pad of pulp. The dirt usually consists of shives or unbleached wood.

A pile of paper which lies in a concave rather than a flat condition. Also applied to the appearance of the end of a roll which is not flat.

A special grade of chemical pulp made from wood or cotton linters for use in the manufacture of regenerated cellulose (viscose rayon and cellophane) or cellulose derivatives such as acetate, nitrate, etc.

A thin plate or scraper of wood, metal, or other hard substance placed along the entire length of a roll or cylinder to keep it free from paper, pulp, size, etc., and thus maintain a smooth clean surface.

Strips of metal or high density plastic placed on dryer cans or other rolls that scrap the roll as it revolves. This is to prevent build-up of material from forming on a roll as it runs.

Dust that accumulates on doctors. It usually consists of fuzz from the paper. It may be attracted to the paper from the doctor and be pressed into it.

Aero surface cleaning system consisting of a vacuum head with a conical suction pipe and a dust extraction unit. The cleaning effect is even and continuous across the full width of the web.

System for the improvement of printing properties of coated board and papers as well as art board.

Brush rollers used as cleaning rollers for polishing, smoothing, matting and moistening. High-precision brush rollers are also installed in DOX Brush Finishing Systems.

Brush roll spray system to provide an absolutely uniform, very fine spray, across the sheet width.

Electrostatic spray system to re-moisturize the paper.

Dust removal device for circular knives.

Print paper cleaning system.

Spray system to control the average moisture level.

The flow of water through the forming fabric and from the stock as the sheet is formed on the fourdrinier of former.

A term used to describe the speed difference between the stock jet and wire. The wire travels faster than the stock and "drags" it.

(1) The difference in speed between two sections of the machine used to "draw" or pull the sheet from one section to the next.
(2) In trimming paper, the displacement of the cut sheet by the thickness of the knife; this is a common cause of inaccurately cut paper.
(3) The tension applied to the paper between sections of a paper machine, such as the press section or dryer section.

A covering over the whole or part of the drier section of the paper machine or coating unit which serves to collect the hot moisture-laden air from the drying process and exhaust it through suitable fans and duct work. It is designed to control air flow for uniform and rapid drying.

The system of motors and controls used to turn the machine sections.

The rolls on the winder bed also called bed rolls.

(1) The area of the paper machine from the first dryer can to the winder.
(2) The part of the paper machine where the paper is dried.

(1) The steam-heated metal cylinder or "can" which the paper passes over to be dried.
(2) The steam-heated cylinders over which paper in the web is passed to be dried.

(1) Generally speaking, any paper that is designed for the reproduction of multiple copies by processes such as Mimeograph, spirit duplicating, Ozalid, etc.
(2) Specifically applied to paper for copies produced by transfer of small portions of aniline ink from a master copy to many sheets of copy paper. In the gelatine process, the ink is held by a gelatine blanket, which gives up a little of the ink to paper pressed in close contact with the blanket. In the liquid process, or spirit process duplicating, each sheet of copy paper is moistened with a small amount of spirit (alcohol) which comes in contact with the master (paper) and dissolves a little of the dye to make a copy. Paper for spirit duplicating must have a smooth surface and controlled absorbency to pick up just the right amount of spirit.

Chemicals used to import a certain shade of color to the paper.