Compressible foam bases for corrugated printing

Cardboard boxes with folding bottoms, folding boxes, displays or sales packaging for transport and for the presentation of goods are printed in high quality post print.

With corrugated printing, adapted printing plates and compressible foam bases are needed due to the different kinds of cardboard with different corrugate wave profiles.

Different types of cardboard from rough, medium, fine or ultra-fine and micro-corrugated demand compressible  bases in different degrees of hardness.

With F-flute quality, an extremely fine cardboard, hard and thin printing plates are mostly used with a soft foam base. Also, EB-flutes demand soft foam bases. With E-flutes, the ultra-fine or micro-corrugated material, medium-hard printing plates and hard foam substrates are selected.

Individual printing requirements in post print and/or direct printing!

The high demands placed e.g. on the reproducibility of printing orders requires the perfect setting up of all parameters with sheet rotation flexographic printing, also called cardboard printing or corrugated printing.

Corrugated printing is used with smaller print runs in particular. In sheet flexographic printing, the cardboard sheets are printed by sheet rotation flexographic printing machines with straight sheet transport.

The gauge-pin accuracy is determined by the printing machine. The large printing plate cylinders of the sheet fed printing presses in corrugated printing do not permit mounting of the printing plates within the machine.

For this reason, specialists at the reproduction service providers and engravers do the preliminary work. Here, printing plates are laminated with a PET film, possibly provided with a hung border and prefabricated with a suitable compressible foam base. Plate mounting is already taken into consideration, so that the printer only has to mount the assembly into the printing cylinder.

Assembly of the printing plate with PET film and DuploFLEX^® CB foam base

Digital mounting of the printing plates on an assembly machine

Mounting the printing base onto the print cylinder

High quality polymer foam: the best basis for consistently high-quality print results

The foam:

High quality polymer foam is used with the DuploFLEX^® CB range. Lohmann has also accompanied and promoted further advancement in the area of foam substrates with its many years of experience.

High quality polymer foams (DuploFLEX^® HP) are already used successfully in the printing of decorative and special colours in flexible packaging printing.

With corrugated printing, the closed cell high quality polymer foam DuploFLEX^® CB convinces with its perfect resilience characteristics and a particularly high stability in compressibility. Furthermore, these foams have extraordinary chemical resistance and avoid producing ‘wash board’ effects as far as possible.

Different foam hardnesses are used according to the corrugated profile and printing plate thickness.

DuploFLEX^®CB

The compressible base is laminated at the engravers with a polyester film or used already finished with laminated film. Depending on which mounting option the printing machine allows, PET films of different thickness are needed. Besides simple self-adhesive polymer foam, Lohmann has a 250 µm thick PET film at its disposal which is already laminated with the foam.

Liner
Adhesive
High quality polymer foam

Laminated PET film
High quality polymer foam

CB – adhesive on one side:

The underlying foam for post print, which is adhesive on one side, is usually applied retrospectively to the mounting film. In this case, a polyester film provided with a tension rail and the printing plate is fixed with double-sided tape. Finally, the CB foam which is adhesive on one side is laminated to the back of the structure.

hard foam
in different thicknesses







soft foam
in different thicknesses
 

CB with PET film carrier:

If the PET film is already laminated onto the foam, then the retrospective lamination by the engraver is no longer necessary. This is an advantage with large-area printing plates. In the case of DuploFLEX^®CB with PET film, the mounting film overlaps enough that the tension rail can be simply attached. Partial removal of the foam from the film is thus very simple.

hard foam
in different thicknesses







soft foam
in different thicknesses