Digital printing of ceramics

Digital printing of ceramics and decals

Digital printing of decals and ceramic tiles is already well established. Computer generated images can be printed directly onto ceramic tiles via special inkjet systems. Alternatively a photocopier type system can be used to print onto decal paper. Of course both these systems require special machines and ceramic inks or toners to produce optimum results. Nevertheless these systems are causing a revolution in the ceramic tile industry.

The detail of decal printing

Ricoh desktop ceramic printer

In the case of digital decal, you can either create a drawing or photograph and then convert it to a digital image suitable for printing on to decal paper. The image is produced as a decal by a photocopier type machine. After printing the image is sealed to the paper with a covercoat and allowed to dry. The decal can then be applied in the same way as conventional decals by a water slide method. Decorators have the choice of either outsourcing decals (small quantities) or for large quantities buying a machine and toners and printing themselves..

The detail of ink jet printing of tiles

Pigment	System	Temperature	Colour
Yellow	Zr-Si- Pr	1250 °C
Red Magenta	Zr-Cd-Si-Se	1250 °C
Cyan	Zr-V-Si	1250 °C
Black	Fe-Cr-Co-Ni	1250 °C
Primary 4 colours used in ink jet printing

In the case of ink jet printing, the digital image is converted to a ceramic image using a specially adapted ink jet printer and special inks. The ceramic tile passes beneath the printer head and the ink jet colour nozzles deposit the image on the tile.

Gamma Ink Jet Tile Printer

Typically up to 10 ceramic colours are used to produce high quality digital images, 4 similar to the primary colours shown above plus additional spot colours. Browns, coral reds and white are commonly used to fill gaps in the colour space. Special printer heads are used to cope with the highly abrasive ceramic inks. For maximum definition and colour intensity special glazes are sometimes used as the base for printing the coloured image. The printed item can be fired almost immediately after drying.

3d Printing of Ceramics

I am constantly amazed at the ceramic challenges I see each year. Whilst making pottery and ceramics is an ancient tradition, new industrial processes and products (or the re-introduction of many older techniques) continue to stretch the imagination.

3d printed sugar bowl

Both in the UK and USA, 3 dimensional digital printing is one such technique. Developed initially for rapid prototyping of plastic objects it is now being used for small special ceramic parts. The potential to build up a ceramic mug  layer by layer  from a computer image is certainly feasible.
 I have seen the initial prototypes which have been glazed and fired. Many technical challenges remain for this process to be viable commercially but I have no doubt that in the long term this will happen.
For more information about this technique see the link project below:-
 University of Bristol project

3d printing using liquid clay syringe

3d extruder printing

This type of printing is also in the early stages of development for ceramics. Many questions remain particularly control of rheology and removing air pockets and machine development.. However the picture on the right shows how the process works. An air powered syringe forces liquid clay out of the nozzle to build up the object in layers. The head could be computer controlled to map out a digital design.
Potentially the ceramic designer can be creative in designing complex forms as well as simple shapes.
Picture and link to more information kindly provided by Ceramic 3D Extruder (FabLabZuidLimburg) / CC BY-NC 3.0

So what does this mean to the hobby or studio potter?

The opportunity to make low cost efficient designs which can be personalised to meet your customer needs. Digital ceramic decals are already established and widely available. But keep following the progress of 3d printing as the potential is endless. Perhaps now is the time to look at ways these techniques can expand your opportunities?

More information and other technical articles on pottery and ceramics can be found at my website The Potters Friend. Go now to sign up for my free newsletter.

How to choose your kitchen or bathroom DIY ceramic tiles

Introduction
Planning and upgrading your bathroom or kitchen is not always an easy task. You are full of enthusiasm but are faced with lots of choices. The choice of ceramic tiles is bewildering. Usually colour, design and budget are the key factors affecting your choice. However I would add a further factor ‘technical performance’. Remember all tiles labeled as ‘ceramic’ are not the same. Indeed some natural mineral tiles such as slate or marble sometimes use the same terminology.

To most people tiles are tiles – aren’t they? Well no! You need to know there are at least 2 categories of ceramic tile; floor tiles and wall tiles. What makes them different is ‘technical performance’. They are both usually made of ceramic, they can both be glazed with a shiny surface and both can be highly coloured with designs. However they do not have the same technical performance in use!

Wall tiles
Wall tiles are usually porous (on the back) and have a highly glossy glaze finish on the face. This allows them to be hygienic, cleanable, and not absorb moisture on the face when exposed to wet conditions in bathrooms and kitchens. However in manufacture they are normally fired in a fast fire kiln in less than one hour. This means they have limited strength, abrasion and slip resistance.

Floor tiles
In contrast floor tiles are fired to a higher temperature usually with a special glaze coating. This gives a much increased strength, abrasion and slip resistance. Clearly this gives advantages when used under foot where stronger tiles are less likely to crack, scratch or wear out as well as resist slipping. Indeed a number of standards need to be met for tiles to be considered suitable for floor tile use. So choose wisely for your location. Floor tiles for floors, and wall tiles for walls!

Colour and finish
A second consideration is tile finish and colour. Although this is generally down to individual taste, for best slip performance floor tiles have a dull gloss or matt texture. Wall tiles can have a much wider range of textures and gloss but a smoother finish is usually more easily cleaned than a textured finish. Please be aware that although most tiles supplied in a box set are matching in design and colour they are not identical!

Quality
Probably the most important aspect of tiles is the quality of manufacture. This is not easy to assess. It means how strong are they? How long will they last? How flat are they (tiles warp during manufacture)? How easy are they to install?

Although most tiles supplied by reputable suppliers are manufactured to European standard BSEN14411 or American ASTM standard equivalents, it is not readily apparent by how much they exceed these standards. In Europe the CE Mark is a sign of quality adopted by tile manufacturers. Established brands like Marazzi or Porcelanosa are constantly pushing the boundaries to produce consistent products which exceed expectation in terms of quality, design and performance.

Summary
In summary, take a little time to choose the right type of tile for your job. Look for the CE marks or the BS standards on the packaging as a sign of meeting a quality standard. Use quality branded products if possible as often they give better performance in use and have been designed for ease of installation.