Filter
Top Products
Calculating Blade Interruption
Blade interruption is the length of time which the blade
interrupts the extrudate during the cutting process. Knowing
blade interruption allows you to optimize blade speed and
design for specific applications.
You can calculate blade interruption for your application if
you know:
● the cutting blade width
● blade speed (cutter rpm)
● extrudate cross section
The rotary knife cut path circumference is fixed for each cut-
ter model:
SC-5 Sure Cut Bushing Knife Cut Path Knife Cut Path
Model Diameter Diameter Circumference
5 2.25" 28" 87.9"
3.25" 29" 91.1"
4.25" 30" 94.2"
5.25" 31" 97.3"
2"x4" 28" 87.9"
2"x6" 28" 87.9"
2"x8" 28" 87.9"
2"x10" 28" 87.9"
3"x6" 29" 91.1"
4"x7" 30" 94.2"
As an example, calculate the blade interruption (in millisec-
onds) for an SC-5 cutter running 1/4 inch (0.250 inch) OD
tubing. The blade speed is 718 rpm and the cutting blade is
15/16 inch (0.937 inch) width at the point where it passes
through the extrudate, and the cut path circumference is 87.9"
for the SC-5.
Calculate the blade interruption time. The interruption time
starts when the blade makes its first contact with the extrudate
and ends when the blade is totally clear of the product (i.e. no
longer interrupting it). Because we know the blade travel
speed, we can calculate the interruption time if we know how
far the blade travels during period of interruption. This dis-
tance is equal to the sum of the extrudate outer diameter and
the blade width at the point of contact.
Blade interruption = (Product OD + Blade width)
X 60,000
time, msec Knife circumference rpm
CUTTER BLADE SELECTION AND USE UGE059/1003
B-4 APPENDIX
C
UTTER BLADE
SELECTION
AND
USE