Mini-Encyclopedia of Papermaking Wet-End
Part Two: Definitions and Concepts
Jet-to-Wire Speed Difference
Papermakers adjust the jet-to-wire speed difference to fine-tune the paper structure. The "jet" is the narrow stream of papermaking furnish that comes out of the slice opening from the headbox. The "wire" is the continuous belt of forming fabric. Often it is possible to improve the uniformity of paper by running at a non-zero jet-to-wire speed difference. "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 difference tend to align fibers in the machine direction.
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