LACO Coating Units

The UV- Hybrid coating technology is a special coating application method, which leads to/results in matt-gloss effects with

structured surfaces (comparing to the results if UV- coatings are applied through photopolymer plates on matte

surfaces/substrates).

This matt-gloss coating effect is possible because of the properties of specially formulated conventional oil based overprint

Varnishes and specially formulated UV- coatings. The very different characteristics of these 2 types of varnish and coating

(specially the different surface tensions of both products) enable the graphical effect, which formats if the coating materials are

applied wet-on-wet over already dried printing inks, printed on absorbent substrates like paper, board, labels etc. On plastics

this method is not suitable.

Hybride UV- coatings can only be applied over already dried printed sheets. An inline production is therefore only possible, if

UV- inks are used for the printing process, which have to be fully dried/cured (by interdeck UV- dryers), when they arrive at the

last printing unit with a LACO coater.

Functional principle of the UV- Hybride coating application:

For the production of an UV- Hybrid matt-gloss effect coating job, a specially formulated oil-based overprint varnish gets applied

on the last printing unit of a Heidelberg press in 52 cm size. All parts of the printing job, which should show high gloss, have to be

free of overprint varnish.

Over the just printed varnish, a special UV- coating gets applied wet-on-wet in full sheet size through rubber blankets on the

imprint cylinder of the LACO coating unit. Over each printed varnish areas, the UV- coating will shrink to a matt appearing

structured surface as soon as the coating touches the wet varnish. Over all varnish-free areas, the UV- coating will wet out

properly as usual and gives the well known high gloss and smooth UV- coating surface.

The simultaneous application of spot overprint oil varnish and full size UV- coating results in a spot UV- coating job without the

need of using a Photopolymer-plate for the UV- coating application, which is expensive to manufcature and would need quite

long time to make register.

The advantage of the special Hybride UV- coating method is first of all a cheap and time saving possibility to do spot UV-

coating jobs, enabling to show finest lines, signets, letters or other graphical parts and pictures through the matt- gloss difference

effects.

An anti- offset spray powder application over the printed sheets can be avoided or at least sufficiently reduced, as the surfaces

of the sheets are covered with cured UV- coating.

To produce jobs with the UV- Hybride system, following machine configurations are recommended:

Offline: - Heidelberg 52-1 or 52-2 colour press

- Laco 52 coating unit

- mobile conveyer UV- dryer with at least 180 Watt/cm curing speed

If a 2- colour press is used for an offline production, increased print finishing results can be achieved, because on the first

printing unit the pre- printed sheets can be “powder cracked”. Thus results in a higher surface quality comparing to an application

on a single colour press.

Inline: - Heidelberg 52-5 press with full UV- equipment for UV- inks production

- Laco 52 coating unit

- mobile conveyor UV- dryer + inter deck UV- dryer (between unit 4 + 5)