Glossary / B

Back–pressure power
Generation of both heat and electricity from fuel; gives greater efficiency than condensing power.

Solid, compressed stack of pulp or paper sheets.

Banknote paper
Highly resistant, age–resistant, suitable for 4–colour printing, with watermark and other falsification safeguards such as embedded metal strip. Often containing cotton fibres (See "Rag paper").

Basis weight
See Grammage.

Fibres located in the inner bark layer of trees and in outer portions of other fibrous, woody plants.

The ease with which pulp can be beaten to achieve the desired properties.

Mechanical treatment of fibres to improve fibre bonding.

Bible paper
Thin, high quality printing paper, with an average grammage of 30 gsm, but wich be as high ad 40/50 gsm, and which has a fairly high density. It is a woodfree, bleached fibre paper, and the better grades contain rag. It needs to be strong, to be a particularly resistant to tears and creasing, and it must have a closed structure. Usually very opaque, the presence of gar and a high percentage of fillers with strong covering power, primarily titanium dioxide, help to improve its printing properties.

Biological waste water treatment
A method of cleaning up waste water using living micro–organisms such as bacteria. See: Activated sludge treatment, Aerated lagoon, Anaerobic process.

Sludge formed (in the aeration basin) during biological waste water treatment or other biological treatment process.

Black liquor
Mixture of cooking chemicals and dissolved wood material remaining after sulphate cooking; recovered during pulp washing, concentrated by evaporation and burned in the recovery boiler to regenerate the cooking chemicals and generate energy.

Bleach plant
Department of a pulp mill where pulp is bleached.

Bleached lined folding boxboard
Bleached lined folding boxboard is a multi–layer paperboard that has a bleached woodfree liner on one or both sides. Between two liners there are intermediate layers and middle layers of mechanical or waste paper pulp.

Bleached pulp
Pulp whose natural brightness has been improved using chemicals.

A chemical treatment used to whiten, brighten and improve the performance of pulp (the lignin in the wood is oxidised).

Blotting paper
Bulky, highly absorbent, filler–free paper which is mostly produced from pure cotton in the form of bleached linters and from chemical pulp.

Book paper
Woodfree or mechanical paper used for printing book.

Paper product with grammage in excess of 400 gsm, made in several layers and laminated when wet or sometimes stuck together with adhesives (casein, starch paste, animal glue, etc.). In some types the different layers have the same fibre composition, whilst in other the outer layer (the cover) is made from better quality materials to improve its surface qualities.

Addition of optical brighteners to the stock to make the pulp/paper appear whiter.

A measure of the whiteness of pulp and paper.

This term is applied to the waste generated during the various production processes, from books, magazines, used packaging, as well as the waste and trim generated by the papermaking process itself. It may be blank or printed. In the latter case, it has to be de–inked if it is to be used for the production of "fine" paper.

Brush glazing
Glazing of coated paper with the aid of brushes.

Bulk product
A mass–produced product sold in large volumes without individual specifications, usually in compliance with a standard. For example, newsprint.