Gap Forming

Gap formers act as an alternative to the Fourdrinier paper machine. They receive furnish which is injected into the head box through a gap of air onto a twin wire unit. As the furnish passes between the wires, moisture is removed from the fibers through the wires forming a paper web from the pulp between the wires. Rolls, blades, or vacuums facilitate the removal of excess water from the web, known as dewatering. The forming sections are very short and the formation takes place in a fraction of the time it takes for a Fourdrinier machine. The gap former produces a paper of equal and uniform quality at a higher rate of speed. If the former is coupled with the press section rebuild or an improvement in the drying capacity may increase the production capacity by up to 30%. However, retrofitting the gap former increases the retention losses. Energy savings from gap formers come from reduced electricity consumption (Kramer et al., 2009. p.104).


Development Status Products

Gap FormingCosts & Benefits

Parent Process: Papermaking
Energy Savings Potential

Estimates for the electricity savings are about 40 kWh/ton of paper (Kramer et al., 2009. p.104).

CO2 Emission Reduction Potential

A study estimates the cost of installing a gap former with head box to be $75,750/inch of width (1996 dollars) (Kramer et al., 2009. p.104).

Gap Forming Publications

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Gap Forming Websites