Vacuum Tension Rolls (VTR) — also known as Vacuum Pull Rolls (VPR) — are hollow rollers with perforated outer shells through which a vacuum is pulled. The VTR stationary centertube is outfitted with internal seals or deckles to create a confined vacuum zone. The pressure differential between the internal vacuum zone and external atmosphere creates a holding force, working with the effect of friction between the roll surface and the web running over it. A drive pulley or journal connected to the outer VTR shell holds back or pulls the web to alter or isolate web tension.
Vacuum tension rolls from PRS feature durable designs that web coaters and converters can use to dial in precise tension levels for optimal performance.
- Diameters ranging from 175 mm (6.890 inch) to 450 mm (17.717 inch) in a variety of standard finish options.
- Custom-engineered sizes and finish options are also available.
Vacuum Tension Rolls (VTR) offer single sided contact with sensitive substrates that can eliminate scratching or other potential damages. Removal of the air boundary layer improves constant tension control in all zones and enhances the ability to process lightweight materials at minimal wrap angles.