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
H FACTOR It is the area under the curve when relative reaction rate is plotted against cooking time.
HALF FOLD The half fold is commonly used for brochures and greeting cards. For cover weight paper, a score is usually required to produce a smooth folded edge. For picture of this type and other fold please visit http://www.bradenprint.com/pdf/Folds-IS.pdf
HALF + LETTER FOLD This fold is perfect for newsletters. An 11" x 17" sheet folded this way has only one open side and fits into a #10 envelope. The newsletter looks good and is easy to handle. For picture of this type and other fold please visit http://www.bradenprint.com/pdf/Folds-IS.pdf
HALF TONE Picture with gradations of tone, formed by dots of varying sizes in one colour.
HANDFEEL See softness
HANDMADE PAPER A sheet of paper, made individually by hand, using a mould and deckle.
HARD COOK Undercooked pulp with respect to target conditions.
HARD PULP Chemical pulp with a high lignin content.
HARD SIZED PAPER Paper treated with high degree of internal sizing.
HARDWOOD Wood from trees of angiosperms class, usually with broad leaves. Trees grown in tropical climates are generally hardwood. Hardwood grows faster than softwood but have shorter fibres compared to softwood.
HEAD BOX OR FLOW BOX OR BREAST BOX The part of the paper machine whose primary function is to deliver a uniform dispersion of fibres in water at the proper speed through the slice opening to the paper machine wire.
HEART WOOD The dark collared , center of a tree trunk, consisting of dormant wood.
HEAT SET WEB An offset printing process done on a web of paper supplied in a roll. The term heat set originates from the inks used in the process. They contain high amounts of solvent flashed off in ovens to dry at very high speeds. Web presses perfect or print both sides of the sheet simultaneously.
HEAT TRANSFER PAPER The paper used in Thermal transfer printing (Sublimation printing).
HEMICELLULOSE A constituent of woods that is, like cellulose, a polysaccharide, but less complex and easily hydrolysable.
HERBACEOUS PLANTS Non-woody species of vegetation, usually of low lignin content such as grasses.
HICKEY An irregularity in the ink coverage of a printed page. Hickeys are caused by paper or pressroom dust, dirt, or pick out on the printing blanket, all of which prevent the ink from adhering to the paper surface.
HIGH FINISH Smooth finish applied to paper to improve the printing surface.
HOLD OUT Resistance of paper surfaces to the absorption of ink. High Hold Out offers higher resistance to ink absorption. Regular Hold Out allows greater ink absorption.
HOLOCELLULOSE The total carbohydrate fraction of wood — cellulose plus hemicellulose.
HOLOGRAVURE Printing process by which great continuous 3D depth is achieved using textures and patterns.
HOOD A hood covering the paper machine drying section and designed for moist air removal.
HOT MELT A type of glue or adhesive applied while hot/warm.
HOT GROUNDWOOD PULP Mechanical pulp produced by grinding logs that have been pre-treated with steam.
HYDRATION The prolonged beating or refining of cellulose pulp in water to reduce it to a semi-gelatinous mass.
HYDROGEN PEROXIDE BLEACHING A method in which pulp is bleached in an alkaline environment with hydrogen peroxide (H2O2), sometimes using oxygen reinforcement. The method considerably reduces the need for chlorine-containing chemicals in the final bleaching of chemical pulps.
HYDROPHILIC Having strong affinity for water.
HYDROPHOBIC Lacking affinity for water.
HYDROPULPER An equipment used to slush broke/paper in to pulp.
HYGROSCOPIC Having the property to absorb water vapour from the surrounding atmosphere. Most of the papers (except glassine, greaseproof or wet strength etc.) are hygroscopic in nature.