Belmark Industries

Other Details

Bow Roll is known as spreader Roll, bowed Roll, Curve bar Expander, Banana Roll, Wrinkle removing Rolls, Bow rolls are available in hard chrome surface, rubber surface and also PTFE covering for non-sticking applications.   Hard chrome surface bow Rolls are used where speed is more than 300 meters minutes. If the speed is more the bigger diameter is used to reduce the rpm of the roll. Bow roll works only when there is proper lead-in and lead-out distance and kept the roll in proper warp angle with web material.  To do such warp angle adjusting all rolls are supplied with bow angle adjusting worm-worm wheel gearbox with hand wheel and counter pedestal bearing block, by use of this it is possible to adjust the bow angle at 360 degree warp angle.  When the Roll get maximum wrinkle removing stop the bow angle adjusting and put the roll on bow locked position,  so not do any change in the bow setting. On Roll shaft bow position indication with arrow showing the bowed position of the Roll.

    Rubber sleeve covered.
    Metal expander with hard chrome plated surface for high speed application.
    PTFE sleeve for non-sticking application.

Bow Rolls are known as Banana Rolls, Spreader Rolls, Curve rubber expander, useful for removing of wrinkles, slack edges, spreading and slit separation. Most of the Expander Rolls are driven by web tension itself without any extra drive. Used in Textile processing machines, Plastic converting machines, Paper Industries, in manufacturing, processing, printing, laminating, coating, Batching, Winding and Re-Winding.

Metal is used for before high-speed Paper slitter re-winders for wrinkle removing and after slitting to separate slits.  This type of Roll having heavy weights and paper tension itself not sufficient to drive the Roll so extra pulley is provided to drive the metal Expander Roll.

PTFE Expander is particularly used before size press where wet working and extra drive is required for to get roll rotate. PTFE rubber bow roll having application where sticking of substance on roll is problem.

All type of Expanders is available in Bow angle adjustable type so one can adjust the bow angle when the machine is in working condition.  Fix the Roll at best bow warp angle it gets maximum spreading, wrinkle removing or slit separating effects.  The diameter of the Roll depends on speed of web materials and maximum web width and also the mounting center.

For 650 mm web width and web speed of less than 50 meters/min a bow roll of 90mm is sufficient with a shaft diameter of 30mm. For 4500mm web width, 1000mtrs/min speed requires minimum diameter of 160mm roll and shaft diameter of 75mm or above. Bowed Roll is available in foot or flange mounting as per specific requirements.