DigiGRÉS

DigiGRÉS – Research and Development of a Fine Stoneware Tableware Range with Digital Decoration

The digiGRÉS project, to be carried out in consortium by Grestel and the University of Aveiro, has as its main objective the development of a range of fine stoneware tableware products decorated through digital printing (digiGRÉS line) and treated with laser radiation. This represents a key step in the modernization and innovation of the company’s products and business model within the context of Industry 4.0, making it more competitive both nationally and internationally.

To make this ambition a reality, the project includes research in two fundamental areas:

• Products & Materials – Development of new inks and glazes that allow differentiation of effects and decorations beyond current digital printing practices (photo and decal reproduction), as well as the creation of new inks for digital printing of back stamps that can be treated with laser technology.
• Processes & Technology – Implementation of an experimental production line to pioneer and innovate the following processes:
  • Digital printing technology for inks, glazes, and adhesives to create special decorative effects, taking into account the geometry (height) of the pieces and positional adaptation of the decoration.
  • Laser technology for the treatment of back-stamp inks.
  • Automation and control of granulation application processes to complement decoration, in line with digital glue printing.
  • Machine vision and robotics to address the challenge of positioning, inverting, and centering each individual piece – particularly irregularly shaped items – for both digital printing and laser treatment.

The digiGRÉS project will thus strengthen the combination of advanced technology and Grestel’s expertise, offering the international market an original range of products with high quality, durability, and exclusive design.

Specific Results:

This project allowed us to acquire a digital printing machine originally designed for flat pieces (flooring and wall tiles), which was adapted to accommodate the diversity of tableware pieces in terms of height, shape, and size.

With the purchase of this equipment, it became possible to create the first prototypes of stoneware pieces from the digiGRÉS line, decorated via digital printing, with maximum heights between 60–80 mm. The prototypes meet Grestel’s quality and food safety standards.

In addition to 2D decorations, it was also possible to achieve 3D or relief decorative effects by applying commercial granules over digitally printed designs. Furthermore, the first back-stamp ink was developed (prepared for digital printing) and subsequently sintered using a CO₂ laser system operating at 30 W, with a scanning speed of 5 mm/s and a distance of 16 mm from the sample.