Digital printing and embossing

Abstract

A method and equipment to form a digital print by applying dry colourants on a surface, bonding a part of the colourants with a binder and removing the non-bonded colourants from the surface. Also, a method to form embossed structures. Hard press particles may be applied in patterns on a carrier that is pressed against a surface.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]The present application claims the benefit of U.S. Provisional Application No. 61 / 751,418, filed on Jan. 11, 2013. The entire contents of U.S. Provisional Application No. 61 / 751,418 are hereby incorporated herein by reference in their entirety.TECHNICAL FIELD[0002]The disclosure generally relates to the field of digitally created decorative surfaces for building panels such as floor and wall panels. The disclosure relates to powder based colourants and hard particles that may be used to create decors and structures on such surfaces.FIELD OF APPLICATION[0003]Embodiments of the present invention are particularly suitable for use in floors, which are formed of floor panels comprising a core or a body, a decorative layer and preferably a transparent wear resistant structured layer above the decorative layer. Preferred embodiments are conventional laminate floors, powder based floor, wood floors, plastic based LVT floors and ceramic tiles. The...

AI Technical Summary

Benefits of technology

[0075]Thermal printing with heating print heads are also used to create digital prints directly on a heat sensitive paper or indirectly with a thermal transfer printing method where the heat is applied on a heat sensitive transfer film. These printing methods are mainly used to apply one colour on a paper and to print for example labels. The heating print heads have several advantages. They are reliable since there are no risks for clogging of inks and the price is cost competitive. The major disadvantages are related to high cost for the paper or transfer film and the colour limitations to mainly one colour. Heating print heads are available in widths of up to 200 mm and may provide a resolution of up to 600 DPI.

[0076]Digital printing is a very flexible method that may provide a high quality print but

Problems solved by technology

The disadvantage is that they are less transparent and the decorative pattern is covered by a grey layer that disturbs the printed pattern.

The production process is rather complicated and is only cost efficient in very large production volumes.

It is more difficult to create designs such as for example wood decors.

The penetration is however rather limited since the ink drops will be bonded to the first particle that they hit, mainly the wood fibres.

Additional circumstances that that have contribute to the introduction of the digital printing technology in the tile industry is the fact that ceramic tiles are rather small compared to for example laminate and powder based floors that are produced as large pressed boards of about 2.1*2.7 m. Rather small printers with limited number of print heads may be used in the tile industry and the initial investment is rather limited.

However the volumes are still very small, especially in wood and laminate flooring applications, mainly due to high cost of the ink and high investment cost for the industrial printers.

The flexibility that the digital printing technology provides is limited by the embossing that is fixed and not possible to adapt to the variations of the digitally printed décor.

Such printers are slow but one small print head can generate a bigger image.

However a part print is not as flexible as a full print since the base colours are more difficult to change than when a full print is used.

Thermal technology imposes the limitation that the ink must be heat-resistant, generally up to 300° C. because the firing process is heat-based.

This makes it very difficult to produce pigment based multi colour thermal heads.

A main problem for all types of inks and print heads is that when ink dries by evaporation it may dry up and clog the nozzles.

This is difficult particularly at the rather low viscosities, which are required for a good functioning of the print heads.

Pigments have a natural tendency to settle out and fall down in the liquid carrier.

The inclusion of resins that serve as binder in the ink composition limits the possible amount of pigments, as both components increases the ink viscosity.

Colour pigments as raw

Images