Flying Knife Cutter


To produce flexible and semirigid tubing and profiles applications, such as PE tubing, weather-stripping, edgebands, gasketing, and PVC hoses, and rubber profiles, you need for a fast and clean cut in your extrusion production line. The HARDEN Fly Knife Cutters deliver the blade velocity and weight in motion to deliver a precise cut regardless the application. HARDEN’s high-torque Rotary Fly Knife Cutter can accurately cut a variety of extruded applications and is ideally suited for processors who make one or several product changeovers within a limited time frame. The Fly Knife Cutter with servo drives allow for greater cutting accuracy and minimize maintenance and downtime of the unit.

tubing cutter gasketing cutter


Why use a fly knife cutter over that of another cutting method?

  • A smaller part will experience grab, movement and a rougher cut due to the size of the cross section of the part relative to the tooth size of a saw blade.
  • A shorter section of profile cannot be cut by a saw since it needs time for the cut cycle. All of the machine actions may take several seconds and depending on line speed of the profile, restricts minimium length of profile.
  • The need for a fast & cleaner cut: An alternative to the fly cutter is a guillotine but the downside of this style of unit is that the stroke, usually much slower in getting through the profile, and it will stop rigid or semi-rigid profile movement enough to cause back-lash thru the takeoff and translating back to the die.

Key considerations in fly knife cutter design

The key considerations in fly knife cutter design is blade velocity and the knivfe weight in motion. The ability of the cutter to complete the cut is a reflection of the speed of the blade and the inertia it has built into the rotation through the profile.  By offering a 12 Inch diameter fly wheel, we are cutting the profile with much greater velocity then 4 Inch fly wheels – since t

The first consideration is the blade speed, as the blade of a harden fly knife cutter travel faster at its long diameter to complete the circle in the same time allowance. The second consideration is the weight in motion, by offering a inch thick fly wheel with a larger servo motor, we have the weight and inertia behind every blade cut to handle even the toughest of applications.



Features of Fly Knife Cutters

  • Compact rotary cutter is aimed at lighter duty cutting applications. Despite the small foot-print, this machine can perform.
  • Available as a table-top unit for off-line use or as an in-line version complete with a floor-standing base.
  • Continuous and on-demand cutting cycles
  • Optional Electronic Length Control


fly knife cutterFly knife cutter,  Model RC32

Servo motor driven cutter:

  • Cutting Through the impact cutter which installed on the servo motor.
  • Blade control by servo positioning controller

Technical Data:

  • Section diameter:  Max. = 32 mm
  • Speed: 50 m/min
  • Min. cutting length:   10 mm

Fly Knife Cutters can be built to your specification or you can choose our standard model, the RC32.


Watch the flying-knife cutter working