The WINertia AV roller was specifically designed to provide 100% traction by displacing air that gets trapped between the roller and the web. Without displacing the air, the roller will lose traction with the web and start to slip. Slipping causes web damage, misregistration, and premature roller surface wear. Spiral grooved rollers do not have the parking capacity to displace the air.
The other issue is that the air does not have enough time to go into the grooves which is why spiral grooved rollers lose traction when running at higher speeds. Winertia AV rollers can also be machined to spread the web. We can add a reverse crown profile to the roller which will negate the effects of deflection and will gently spread the web. We recommend the reverse crown profile for most applications.
Spiral groove rollers have the appearance of web spreading (example barber pole) but do not actually spread the web but spiral grooved rollers typically condense the web. As tension is applied, the web is pulled into the grooves. This causes the web to trough and condense. This will affect the finished product in the rewind. If you have any doubts or concerns, take us up on our performance guarantee. You can purchase one roller from us and test it out for 60 days. If it does not meet or exceed your expectations, you let us know and we will credit the invoice.