WESPATT, Inc. Tail Threading - Products

Products > One Pass Systems

ONE-PASS® Pneumatic Tail Threading Systems rely on the Coanda effect in automatically controlling the tail threading process to eliminate errors associated with hand threading. They fully function for a wide range of applications and a full range of paper grades.

Once installed, the system is operated through an easy-to-use control panel specifically designed for your applications. Custom-engineered mountings allow ONE-PASS® threading components to swing out of the way for normal tending and equipment operation requirements. Low maintenance with virtually no moving parts assures minimal system attention, wear and adjustment.

The Coanda Effect: An aerodynamic phenomenon called the Coanda effect is used to guide the motion of the tail as it follows the threading path established by the carefully engineered ONE-PASS® systems. In most basic terms, this effect is the tendency of a moving stream or flow of air, when emerging under pressure from a nozzle or narrow slot, to follow an adjacent curved surface.

As the air accelerates along the foil, it reduces atmospheric pressure at the surface, creating a partial vacuum. As the air pressure pushing down from above remains constant, the partial vacuum at the airflow adheres the introduced paper tail to the curved surface. This airflow carries the tail in the exact path determined by the air foil design, accurately moving it to the next machine station.

Air Foils
Tail Clippers
Wet Press
Mountings