TSpan is the creation of Clarence Klassen of KlassENgineering Inc, klassen.on.ca
and has been put into App format by Steven Abbott
and has been put into App format by Steven Abbott
Instructions and Terminology
The TSpan application uses the model of tension in a span between two traction points. Idler roller drag and inertia are not considered as they complicate the model enormously and most often idlers have only small effects.
The model comes from research at Oklahoma State University1.
This model shows the incremental tension response to a step change in speed at the 2nd roller in a web span.
A stready differential change in speed at the 2nd roller is often called draw. The important outputs are:
Final tension value (N or lbf), including T-in, can be read from the graph.
1Tension Control Kee-Hyun Shin, TAPPI PRESS, 2000, ISNB 0-89852-348-6.
The TSpan application uses the model of tension in a span between two traction points. Idler roller drag and inertia are not considered as they complicate the model enormously and most often idlers have only small effects.
The model comes from research at Oklahoma State University1.
This model shows the incremental tension response to a step change in speed at the 2nd roller in a web span.
A stready differential change in speed at the 2nd roller is often called draw. The important outputs are:
- The time constant Tc of the tension model. This is the time to reach 63% of the steady-state tension value.
- The steady-state tension value (N or lbf.) which will be achieved with an incremental speed difference between two rollers. This is commonly described as draw or ratio can be calculated from it.
- The steady-state gain of tension over incremental speed.
Summary of Inputs and Outputs
The aim is to calculate the extra tension in the web caused by an increase in web speed of ΔV. This depends on the following inputs, along with derived output values
| Inputs | |
| T-in | Incoming Tension (N or lbf) |
| Span | Distance between rollers (m or in) |
| Gauge | Thickness of web (mm or mil) |
| Width | Web width (mm or in) |
| Speed | Web speed(m/min or ft/min) |
| ΔV | Change in web speed at the 2nd roller (m/min or ft/min) |
| Modulus | Elastic Modulus of the web(GPa or MPSI) |
| Outputs | |
| Area | Cross-sectional area of the web (m² or in²) |
| Tc | Time Constant of the tension response to a change in speed at the 2nd roller (s) |
| Gain | Steady-state Gain of the tension response (N/m/min or lbf/ft/min) |