Decorating Machine Basics for Ceramics and Glass
Many different techniques using a range of machines are available for ceramic and glass decoration.
The range of available decoration machines is wide and covers different types of techniques. A general understanding of these techniques can help manufacturers choose the right method for their application.
Total Transfer Pad Printing
Total transfer pad printing enables the decoration of all types of pieces in ceramics, glass or enamel steel thanks to the application of ceramic color, glass enamel, or precious metal. This method has been designed to decorate the central area, edges, or the whole surface of plates and flatware articles with up to eight colors. An offset screen is used to print a pattern on a silicone plate, where it is picked up and transferred to the article by a deformed and heated silicone pad.
Engraved Plate Printing
This technique allows the application of high-quality, complex decorations of up to eight colors onto ceramic articles. The decoration is reproduced with very good definition through the use of an engraved plate made of steel or polymer, and then transferred onto the piece using a silicone pad. Both cold and thermoplastic inks can be used since a heating system is integrated. Engraved plate printing is ideal for mass production.
Total transfer and engraved plate technologies can be used to apply high-quality, single-color back stamps onto flatware and hollowware pieces of ceramic or glass. The backstamp can be applied on or beneath the glaze.
Heat-Release Decal Application
Heat-release decals are automatically transferred onto glass or ceramic articles. This flexible technique is ideal for high-quality and high-definition decoration, as well as very small quantities. The process includes an integrated decal storage system, a heating plate equipped with a vacuum system, and a preheated silicone pad. Once the decals have been applied, no additional operation is necessary; the articles can go directly to the firing process.
It is possible to decorate flat, irregular or complex surfaces due to the use of a soft and deformable pad. A variant of this technique enables the decoration of cylindrical and conical ware at 360° through the use of a silicone roller.
Lining and Banding
This technique enables the decoration of flatware or hollowware, round or oval shaped, with either ceramic color or precious metal. Thanks to a special guiding system that follows the edge of the piece being decorated, it is possible to achieve a precise lining or banding. In addition, it is possible to apply two lines or bands, on or under glaze. Ceramic, glass or metal articles can be decorated with this technique.
Laser sintering technology* allows the marking of ceramic, glass or metal articles of all shapes and sizes, in small or large production runs, while providing benefits such as cost savings, ideal marking contrast, and increased productivity. The different stages of laser sintering include: powder deposition on the substrate (via spraying, screen printing, rotating disk), drying of this powder deposit to avoid any interaction between the medium and the laser, laser sintering, and removal of excess powder.
The powder is usually a mixture of a fusible material, which enables better anchorage on the substrate; a functional element to achieve the required properties (e.g., color, conductivity, refractoriness, hardness); and an absorber, which helps maximize the powder energy absorption at the laser wavelength. The mineral material is fixed on a temperature-resistant substrate (ceramic, glass or metal) at a high temperature by using the energy transmitted by the laser.
The laser used for this process has a power of less than 50 watts and a wavelength close to one micrometer. The laser beam is transported by an optical fiber to the galvanometric head, which enables the creation and marking of the pattern due to two rotating mirrors. At the scanning head outlet, a lens focuses the energy in order to achieve an energy density of a few thousand watts/mm². No subsequent firing is necessary.
The goal of this process is to sinter a mineral powder at a higher temperature than the substrate could withstand. This sintering is possible due to the rapidity of the heat treatment, which takes only a few nanoseconds with a laser beam of a hundred micrometers.
This technology combines all the advantages of a digital process, including customization, traceability and prototyping. Laser sintering enables the decorating of surfaces of about 200 x 200 mm, and even curved surfaces. Many applications and variations are possible, including logo marking for tableware and sanitaryware, quick customization of articles, traceability (i.e., creation of 2- or 3D code in real time), and authentication together with Naomarq via the addition of a unique optical tracer in the powder in order to certify the product when reading the light spectrum.
Next-generation laser machining systems are used for ceramics and glass machining and cutting. These lasers, characterized by short pulse times and high peak powers, enable micro-impacts to be achieved in the material, which limits thermal stresses. Fragile ceramic parts can thus be machined with complex shapes and depths that are set according to the laser power. In addition, embedded optical systems allow different applications, from simple 2D marking to 3D machining.