Wichita Clutch 'Mistral' Tension Brake - Manual (Page 3)

Tension Brakes/Air Cooled
104 Wichita Clutch 800-964-3262 P-1100-WC 1/12
Selecting a Mistral Brake for a
Corrugator Tension – unwind
application
To properly select a tension brake for an
unwind application the following in for ma tion is
needed.
Application Data
Max. Roll Dia. . . . . . . . . . . . . . . . . . . . . . . 48 in.
Max. Web Width . . . . . . . . . . . . . . . . . . . . 36 in.
Max. Web Speed . . . . . . . . . . . . . . . 1200 FPM
Max. Tension. . . . . . . . . . . . . . . . . . . . . . . 2 PLI
Shaft Size . . . . . . . . . . . . . . . . . . . . . . . . . . 2 in.
Min. Roll Dia. . . . . . . . . . . . . . . . . . . . . . . . 6 in.
Min. Web Width . . . . . . . . . . . . . . . . . . . . 36 in.
Min. Web Speed . . . . . . . . . . . . . . . . 1000 FPM
Min. Tension . . . . . . . . . . . . . . . . . . . . . . . 1 PLI
Air Pressure Available. . . . . . . . . . . . . . . 80 PSI
Calculations
Using the calculations below, consult
Specifications Chart, page 103.
The brake selected for this application is a
Mistral 200/2 with 2-1/4 inch bore.
Max. Tension = Max. PLI x Max. Web Width
= 2 x 36 = 72 lbs.
Max. Torque =
Max. Tension x Max. Roll Dia.
2
= 72 x 48/2 = 1,728 lb.in.
Max. RPM = Max. Web Speed x 3.82
Min. Roll Dia.
= 1,200 x 3.82/6 = 764 RPM
Heat HP =
Max. Tension x Max. Web
Speed/33,000
= 72 x 1,200 = 2.6 Heat HP
33,000
Min. Tension = Min. PLI x Min. Web Width
= 1 x 36 = 36 lbs.
Min. Torque =
Min. Tension x Min. Roll Dia.
2
= 36 x 6/2 = 108 lb.in.
Min. RPM =
Min. Web Speed x 3.82
Max. Roll Dia.
= 1,000 x 3.82/48 - 80 RPM
How to Select
1. Check the required torque versus the
available actuators’ torque capacities. The
Mistral 200/2/LC has a torque capacity of
1,180 lb.in. at 80 PSI. The torque
requirement is 1,728 lb.in. and therefore the
Mistral 200/2/LC has insufficient torque
capacity. However, the 200/2 has sufficient
torque capacity.
2. Check thermal requirement. The
re quire ment is 2.6 heat HP. All the Mistral
200’s are capable of 3.2 heat HP.
3. Check Maximum Bore. The re quire ment is
2.00 inches. The Mistral 200’s maximum
bore is 2.25 inches.
4. Check Maximum RPM. The re quire ment is
764 RPM. The maximum RPM for the Mistral
200’s is 2,860 RPM.
Max. Air Pressure
Required =
Max. Torque x 80 PSI
Catalog Torque Rating
= 1,728 x 80/1,770 = 78 PSI
Min. Air Pressure
Required =
Min. Torque x 80 PSI
Catalog Torque Rating
=
108 x 80
1770
= 5 PSI
Mistral Brakes