Tension control on sheet materials
Processing sheet materials means keeping the sheet tensioned. If the tension is too little, then the product "sags" and may become entangled. If it is too much, then the product can become overstretched and end up becoming damaged or ripped as a result. In order to accurately determine this tension between two different points in the process, it is essential to measure the velocity at both points. You can then calculate the tension from the difference).
Laser surface velocimeters (LSVs) from Polytec are ideally suited because they can conduct measurements on almost any surface and they are not susceptible to contaminated surfaces. The non-contact measuring technique makes it possible to eliminate any negative influences on accuracy, such as slippage and wear, simultaneously. The product being subjected to the measurement remains intact too. The increased precision in measurement enables you to monitor the tension more closely, thereby optimizing the process while preventing damage to the product from tension fluctuations. The result: You increase quality while at the same time reducing waste.
Practical examples
Polytec LSVs are used in various applications in the paper, cardboard, & packaging industry as a means of regulating tension:
- in joining sheet materials, i.e while changing rolls of paper
- when processing sensitive material such as thin paper
Non-contact LSV velocity sensors in paper production
A Polytec LSV was installed in a paper factory because of frequent downtime when changing rolls of paper in its coating machine. Integrating the LSV into the process control allowed rolling velocities to be aligned exactly with one another with an accuracy of 0.1 %. This resulted in a significant reduction of tension fluctuations when joining the paper webs and has already led to savings equivalent to the investment costs in under a year
Industrial length and speed control with optical sensors
Related products
ProSpeed LSV-2100 Laser Surface Velocimeter
The ProSpeed® LSV-2100 optical sensor determines the direction of motion and standstill conditions with laser precision. It measures reliably even under harsh production conditions with large working distances up to 3 m. Due to the non-contact measurement principle, these laser sensors eliminate common problems of traditional contact-wheel measurement methods such as damage to delicate surfaces, slippage and thermal expansion and work on almost any surface.
ProSpeed LSV-1100 Laser Surface Velocimeter
The ProSpeed® LSV-1100 optical sensor measures in forward direction with laser precision. It measures reliably even under harsh production conditions with working distances up to 1.5 m. Due to the non-contact measurement principle, these laser sensors eliminate common problems of traditional contact-wheel measurement methods such as damage to delicate surfaces, slippage and thermal expansion and work on almost any surface.
Further applications
- Velocity measurement
![Process optimization by velocity measurement during printing processes]( "Process optimization by velocity measurement during printing processes")
Process optimization by velocity measurement during printing processes - Length measurement
![Optical, non-intrusive length measurement of coiled paper]( "Optical, non-intrusive length measurement of coiled paper")
Optical, non-intrusive length measurement of coiled paper - Velocity difference
![Laser precise speed synchronization in slitting processes]( "Laser precise speed synchronization in slitting processes")
Laser precise speed synchronization in slitting processes - Cutting length control
![Cut-to-length control on corrugated board]()
- Position tracking
![Optical position tracking and control for printing processes]( "Optical position tracking and control for printing processes")
Optical position tracking and control for printing processes
