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.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
EDGE CRUSH RESISTANCE The amount of force needed to crush on-edge of combined board is a primary factor in predicting the compression strength of the completed box. When using certain specifications in the carrier classifications, minimum edge crush values must be certified.
EDGE CUTTER Device comprising two jets of water which are adjustable across the wire and which divide the wet web on the wire lengthwise so that the edges may be removed, generally at the couch. In this way they control the width of the web going forward from the wire part and give it comparatively clean edges.
EFFECTIVE ALKALI Caustic (NaOH) and one half of Sodium sulphide (05*Na2S) expressed as Na2O in alkaline pulping liquor.
EFFLUENT Waste backwater and rejects from which fibre is recovered prior to discharge from the mill.
ELECTRICAL GRADE PAPER Strong, pin-hole free paper, sometimes impregnated with synthetic resins and made from unbleached Kraft pulp. Electrical insulating paper must neither contain fillers nor conductive contaminants (metals, coal, etc.) nor salts or acids. Lava stone bars are used on rotor and stator to avoid any metal contamination. Cable papers, that are wound around line wires in a spiral-like fashion, are electrical insulating papers with a particularly high strength in machine direction. Electrical grade papers include cable papers, electrolytic papers and capacitor paper.
ELECTRIC RESISTIVITY Resistivity characterizes how a sheet of paper accepts and holds a charge. Since the electrostatic processes uses an electrical charge to form the print image, the electrical properties of the sheet are important to the overall imaging process.
ELECTRONIC PRINTING Photocopiers, ink jet, laser printers and other similar printing methods that create images using electrostatic charges rather than a printing plate.
ELECTRO PHOTOGRAPHY A printing process that uses principles of electricity and electrically charged particles to create images - e.g., photocopiers and laser printers.
ELECTROSTATIC PRECIPITATOR (ESP) Used to clean up flue and process gases. Removes 99.5-99.8% of dust particles emitted from recovery boilers, lime kilns and bark-fired boilers.
ELEMENTAL CHLORINE FREE (ECF) ECF papers are made exclusively with pulp that uses chlorine dioxide rather than elemental chlorine gas as a bleaching agent. This virtually eliminates the discharge of detectable dioxins in the effluent of pulp manufacturing facilities.
ELEMENT OF A PATTERN A small feature of an embossing pattern, usually completely surrounded by a region that is at a different elevation. Also called an "embossment". If the element is raised with respect to its surroundings, then it is called male. If the element is recessed with respect to its surroundings, then it is called female. With some embossing patterns, an element may contain smaller elements within it (see spot embossing).
ELONGATION A property of paper that allows it to stretch.
EMBOSSING Pressing a shape into a sheet of paper with a metal or plastic die, creating a raised (embossed) image. To change the shape of a thin material or sheet from flat to shaped, so that there are areas that are raised and/or recessed from the rest of the surface, usually without rupturing the material (perf-embossing is the most notable exception).
EMULSION COATING Coating of paper with an emulsion containing plastic or resin.
ENAMEL A general term referring to coated paper that has a higher basis weight than coated publication (magazine) paper but a lower basis weight and calliper than coated cover paper.
ENGINE SIZING Old term used for beater sizing when sizing chemicals used to be added in Engine or Beater.
ENGLISH FINISH A smooth-finished, machine made and calendared book paper. It is soft, dull and pliable. Normally used for letterpress printed magazines.
ENGRAVER A company or a machine that does engraving. In the absorbent tissue paper industry, the word is most often used to mean a company which supplies engraved embossing rollers.
ENGRAVING A printing process using intaglio, or recessed, plates. Made from steel or copper, engraved plates cost more than plates used in most other printing processes, such as lithography. Ink sits in the recessed wells of the plate while the printing press exerts force on the paper, pushing it into the wells and onto the ink. The pressure creates raised letters and images on the front of the page and indentations on the back. The raised lettering effect of engraving can be simulated using a less costly process called thermography.
ENGRAVING The main process used to create an embossing roller (cylinder) or an embossing plate. Engraving changes the surface from smooth to shaped, either by etching (where material is selectively removed) and/or by mechanical force (like knurling). Etching methods include: chemical (acid or solvent), machining, and laser. Steel embossing rollers are usually engraved with a combination of mechanical pressure and acid etching. Laser engraving is a relatively new process for making embossing rollers and is used to etch a special coating that is applied to a steel roller.
ENTRAINED AIR Entrained air consists of bubbles that are small enough (say less than 1 mm) to move along with the fibres.
ENVELOP PAPER The paper made specifically for die cutting and folding of envelopes on high-speed envelop machine.
ENVIRONMENTALLY PREFERABLE PAPER (EPP) EPP should have at least two of the following three characteristics:
1. 30% or more Post Consumer Recycled Content
2. TCF Bleaching
3. Forest Stewardship Council certified Forest Management for virgin fibre sources.
ENZYME A protein that has the ability to direct or catalyze a chemical reaction.
ENZYME BLEACHING Bleaching technique in which cooked and oxygen-delignified chemical pulp is treated with enzymes prior to final bleaching. Allows pulp to be bleached without chlorine chemicals.
EQUILIBRIUM MOISTURE CONTENT The moisture content of a paper that has reached a balance with the atmosphere surrounding it, i.e. in a condition in which it will neither give up nor absorb moisture
EQUIVALENT BLACK AREA Of a dirt speck is defined as the area of a round black spot on a white background of the TAPPI Dirt Estimation Chart which makes the same visual impression on its background as does the dirt speck on the particular background in which it is embedded.
ESPARTO A grass from North Africa which makes a soft, ink receptive sheet.
ETHERS PULP Generally these are high purity, high viscosity pulps that are swollen in sodium hydroxide initially, followed by reaction with organic epoxides or chlorides like ethylene oxide or methyl chloride to form an organic polymer called cellulose ethers (methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, etc.). Cellulose ethers are used for thickening of fluids such as toothpaste, ketchup, shampoos, diet drinks and hundreds of other applications.
EXTENDED COOKING Method of cooking pulp to low lignin content, thereby reducing the need for bleaching chemicals.
EXTENSIBLE KRAFT Very strong virgin Kraft papers which stretches (approximately 6%) more in MD and tears less easily than regular Kraft paper.
EXTERNAL FIBRILLATION A refining action that results in partial detachment of fibrils from outer layer of a fibre.
EXTRACTIVES Any number of different compounds in biomass that are not an integral part of the cellular structure. The compounds can be extracted from wood by means of polar and non-polar solvents including hot or cold water, ether , benzene, methanol, or other solvents that do not degrade the biomass structure. The types of extractives found in biomass samples are entirely dependent upon the sample itself
EXTRUDED COATING Coating applied to paper or board using an extruder.