11-10-2016, 11:58 AM
1458584411-tctech.pdf (Size: 1.09 MB / Downloads: 6)
What is tension?
Tension is the force applied
to a continuous web of
material in the machine
direction
Tautness on the web as if you
hang a weight off the webs
edge
How is tension measured?
• Typically tension is measured in PLI
(Pounds per Linear Inch) in the USA
• PLI = total pounds of tension divided by
web width in inches
• Total web tension = PLI times web width in
inches
Why is tension important?
• Needed to control your web
– Unwind
– Process
– Rewind
• Web handling principal requires web
traction with all idler and driven rolls
Why is tension important?
• Web guide systems will not work without
web tension and traction
• Many wrinkle removal systems like bowed
rolls rely on tension and traction to work
• All webs stretch in the machine direction
Why is tension important?
• Problems at unwind and rewind stations
– Telescoping
– Dished
– Wrinkles
– Web breaks