Companies spend more time and resources than desired from the time a product or service is conceived until it is launched (time to market or TTM). This leads to cost overruns, reduced sales and loss of market position. In the current ceramic economic framework, reducing TTM and costs is more important than ever.
Thanks to advances in technology, many of these processes are now being speeded up. Additive manufacturing (AM) is one of the technologies used for rapid prototyping or even final parts. However, when it comes to sanitaryware, these technologies can only be used to produce non-functional models due to a limited development in ceramic materials and processes. The ability to create functional prototypes that can be used to evaluate properties would increase flexibility in the development of new and innovative products and minimise TTM.
Binder Jetting (BJ) technology was chosen because it requires no supports and allows the part dimensions to be easily scaled without changing the print characteristics and there are already large machines on the market. However, it has been necessary to invest in the development of a suitable material for the intended purpose. Compositions for BJ technology have been developed for the purpose of printing sanitary parts that can be glazed and heat treated in industrial cycles.
To accomplish the main objective of the project, some of the most influential factors for the development of the materials are:
- That it has sufficient green strength. Printed parts do not require to have high mechanical strength at this stage but need to be able to withstand the postprocessing.
- Adequate pyroplastic deformation after sintering. The material must guarantee a dimensional stability after firing.
- Adequate final roughness (after glazing). In order to be able to test some of the properties of the sanitary ware, the roughness of the final pieces must be equal to that obtained with pieces manufactured by the usual industrial process.
Several compositions have been tested with different organic binders, clay minerals, fluxes and conglomerates, being cementitious conglomerates the ones with the best results.
A composition made from a cementitious base and natural rubber as a binder was developed, which made it possible to obtain large format pieces with a green mechanical strength of 3MPa, a pyroplastic deformation of less than 12cm^-1·10⁵ after undergoing an industrial cycle and a surface roughness of less than 0.1µm after glazing.
This work has been made possible thanks to funding granted by the CDTI to the company ROCA S.A. in the framework of the project “3D ROCABATH” (IDI-20190892)