V

PULP AND PAPER DICTIONARY

This page contains definitions of the terms, words and phrase commonly used in pulp and papermaking, printing, converting and paper trading.

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V FOLD                        V-fold has one fold which creates two panels.

VACUUM BOX            See Suction Box

VACUUM PICKUP      Transfer of paper from wire to press felt using a perforated vacuum roll.

VAPOUR PHASE PULPING  Cooking impregnated chips predominately in a vapour phase.

VAPOURPROOF PAPER  Paper or paperboard that has been chemically treated or laminated with vapour barrier so that it will resist the passage of gases or vapour through it. It is typically used for food packaging.

VAT MACHINE            A paper or board making machine comprising one open ended cylinder, or more than one open ended cylinder in series, covered with fine mesh wire, which revolves in a vat of stock. Water draining through the wire leaves a mat of fibres on its surface and the ultimate thickness of the product may be determined by the number of cylinders used. The resultant web is removed from the last cylinder and then passed through conventional pressing and drying sections.

VAT PAPER                 Paper made, usually one sheet at a time by dipping special wire screen moulds in vats of pulp stock and allowing water to drain away by gravity.

VEHICLE                     The liquid part of the ink, giving it the flow properties that enable it to be applied to a surface.

VEGETABLE PARCHMENT  Paper made from pure bleached chemical pulp, which goes through a treatment of sulphuric acid giving it a lasting resistance to grease penetration. This paper is used for wrapping of moist or greasy foodstuffs..

VEGETABLE PARCHMENT

VEINING                        Uneven colouring of pulp.

VELLUM PAPER     (1) Paper finish that exhibits a toothy surface similar to eggshell or antique and is relatively absorbent for fast ink penetration.

                                  (2) A high-grade paper made to resemble parchments originally made from calf’s skin.

                                  (3) Social and personal stationery is often called vellum.

VENTED NIP PRESS A radial groove bottom press roll whose purpose is to reduce the fluid pressure gradient within the nip of the press by providing an area to escape for the water pressed out of paper and felt. Blind drilled roll also used for same purpose.

VERDOL PAPER         A high strength rigid paperboard or pressboard made typically from jute fibres. It is also known as jacquard board.

VIRGIN FIBRE            Fibre that has never been used before in the manufacture of paper or other products.

VIRGIN FOREST        Forest in its natural state, untouched by man.

VIRGIN PULP             Pulp manufactured and used for the first time.

VISCOSE PULP          Dissolving pulp intended for the manufacture of viscose.

VISCOSITY (INK)        A measurement of the fluidity of ink. A higher viscosity is the thicker, and the lower viscosity is thinner.

VULCANIZING             A process to convert paper and paperboard in to a dense, hard, high strength paper by treating it with Zinc Chloride (ZnCl2) and Sulphuric Acid (H2SO4) which gelatinizes the surface cellulose.