Flame Treatment

W3 Winders now come with the option of Flame surface treatment.  This allows successful winding on to Polypropylene (PP) and PVC core tubes which have not been roughened or scratched.

How it works

The main problem with gluing to plastic tubes is that the glue does not evenly coat the tube surface but forms into raised droplets.  The reason for this is that the tube has a much lower surface energy (measured in Dynes) than than the glue.  Our surface treatment raises the Dyne level, allowing the glue to spread as shown below, resulting in far better adhesion.

Untreated surface            Treated surface

The tube is not melted to achieve this improved adhesion, in fact melting the tube results in a very low Dyne level - close to that of the untreated tube (usually less than 35 Dynes).  The W3 Flame Treatment method uses a low temperature, very lean flame which modifies the tube by means of the ionised air in the flame rather than by its temperature.  This also results in very low gas consumption.

Corona vs. Flame Treatment

Our early experiments with surface treatment technology used electrical corona equipment.  However, we found that this resulted in uneven and unreliable results with patches of untreated tube which the glue would not stick to.

The current Flame Treatment improves adhesion by a very similar process, but has the benefit of being much more reliable, treating the tube evenly and effectively.