Hot Stamping Onto Glass - High Gloss Gold and Silver Effects

In the glass decoration market, gold and silver effects are important design elements. With the increasing popularity of organic inks, especially UV-curable inks, there is interest to achieve gold and silver effects coming close to precious metals. 

Although organic gold and silver inks have improved over the years, until today, none of these are coming close enough to the effect of precious metals. The highest gold and silver quality with a similar effect is achievable using hot-stamping foils. However, direct hot-stamping onto glass is not possible. Using a pre-print with a suitable organic primer, hot-stamping onto glass becomes reality. Applying this combination process fulfils two needs: a very attractive high-gloss gold and silver effect at a greatly reduced cost compared to precious metals.

Due to direct stamping onto glass show only inadequate adhesion, a pre-print with a thermoplastic primer is necessary. Applied by heat and pressure, hot foils adhere very well to such primer layers. Marabu offers suitable products in the solvent based Maraglass MGL inks series as well as the UV-curable series Ultraglass UVGL. The desired image is screen printed onto the glass bottle and the subsequent hot-stamp foil adheres only on top of the primer layer. Applying this combination process, a multitude of designs from fine details up to large areas can be realized.

A Further Step Forward

Up till to now hot stamping with Ultraglass UVGL primer was limited to soda lime packaging glass as single image. When using the hot stamping process onto painted glass bottles, a complete readjustment of the process parameters was necessary.  In order that the foil adhered only onto the primer and not simultaneously to the organic painting, the temperature during the hot stamping process needed to be reduced. The window for the temperature would consequently be very tight. An even greater challenge would be hot stamping onto multi colour UV decorations. The foil should only adhere onto the UV primer but not onto the other UV colour shades. As a result, an inline decoration for these desired designs was not possible.  

Organic alternative to bright gold and bright silver

A significant breakthrough in the development of UVGL primers, now, enables Marabu to offer solutions for these two critical applications. In collaboration with hot stamping machine supplier Madag Printing Systems AG and foil supplier Peyer Graphic AG, both Swiss based companies, confirmed that the new primer formulations fulfill the requirements in respect to print detail as well as ideal reception of the hot stamping foil.

Characteristics for the final hot stamping result are: 

•    Very good adhesion only on the desired primed surface
•    Edge sharpness especially with fine lines and details
•    High gloss and an ultra-smooth surface of the foil

Summary

For hot stamping onto soda lime packaging glass, painted packaging glass, and multi colour decoration using a UV-curable screen printing primer Marabu has a solution. Ultraglass UVGL offers best-in-class adhesion, resistance, and the most comprehensive product portfolio – now even wider with the new precious metal simulation solution.

Marabu are exhibiting at InPrint 2015 on booth #D21

Website http://www.marabu-inks.com/