Laminating digital print following corona treatment

[UK Printer]

Morning all,

Wea re experimenting with some things when laminating digital print from our nexpress. We are using the new formulation toner and nothing other than D&K Superstick film will stick to it.

We have carried out some early trials using a corona treatment to the surface of the print prior to the film being applied, using cheap film we have achieved a better bond, but with a bit of effort damaging th edges of the card the laminate will start to peel, there is some grab on the surface of the card, compared to turning off teh corona treatment bar the results are much better.

Just wondered if anyone has been down this avenue, any success?

 

[effeegee]

Some time ago preliminary tests suggested that corona discharge of digital printed sheets (Xerox) improved 'wetting' properties and reduced the effect of fuser oil. However it was not enough to overcome problems associated with wetting for hot melt adhesive for binding purposes. This was conducted in an effort to avoid using PUR.

Tests were abandoned with anticipation that improved toners not requiring fuser oil 'flood' coating would eliminate problems in the spine. This proved true with print engines using 'encapsulated toners but the problem remained in image areas.

Lamination of anything involving fuser oil or solids with 'encapsulated' toners. Practical feeding of sheets and control of discharge parameters to achieve the desired 'wettability' but not impact print quality remain an issue even if tests prove successful.

The main difficulty revolves around the chemistry used in fusing - i.e. designed to stop things sticking!

It is possible that more scientific tests across various parameters would have produced more positive results

By comparison electrostatic charging of sheets achieved short term adhesion but laminate tended to be released after a while.