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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JET TO WIRE SPEED RATIO Papermakers adjust the jet-to-wire speed ratio to fine-tune the paper structure. The "jet" is the narrow stream of dilute stock that comes out of the headbox slice opening. The "wire" is the continuous belt of forming fabric. Often it is possible to improve the uniformity of paper by running jet-to-wire speed ratio as one. "Rushing the sheet" means that the jet speed is higher than the wire speed. "Dragging the sheet" means that the wire speed is higher than the jet speed. Especially in the case of dragging, increasing values of jet-to-wire speed ratio tend to align fibres in the machine direction. For square sheet (paper which has same strength properties in CD and MD), jet to wire ratio should be kept as close to one as possible.
JOB LOT Out of specification, defective or discontinued types of paper made in small quantities for special orders and sometimes sold at lower than regular prices.
JOG To shake a stack of papers, either on a machine or by hand, so that the edges line up. Finisher jog the paper to remove any improperly cut sheet. Printers jog the paper to get rid of any dust or particles and to ensure proper feeding into the press.
JUMBO ROLL A roll of paper, direct from the paper machine, wound on a machine winder spool as distinct from rolls that have been slit and rewound on cores.