Hydrotect® technology is used on licence by more than 100 manufacturers worldwide, and is applied in a range of sectors, from the automotive to the construction industry. The patent holder is the Japanese group TOTO, world leader in the photocatalytic technologies sector, with which Casalgrande Padana signed a Master Agreement in 2012. Bioactive ceramics derive from a series of scientific acquisitions developed from the beginning of the 1970s, but it was not until the mid-1990s that TOTO patented Hydrotect®, a coating able to combine the advantages that can be obtained from the disintegrating action of TiO2 (titanium dioxide), with those of a superhydrophilic surface, which, with the action of UV rays, is able to reduce the contact angle with water, which assists the constant washing away of dirt.

The exclusive formula of Bios Self-Cleaning® is based on titanium dioxide (TiO2), a completely natural substance able to break up the organic deposits that settle over time on the façades of buildings. Because they are superhydrophilic, ceramic surfaces are cleaned by the washing action of rainwater. The self-cleaning process can be summed up in three simple steps:

1. When sunlight (UVA rays) irradiates the surface treated with Bios Self-Cleaning®, active oxygen (O2 -, -OH) is generated.

2. The active oxygen (O2 -, -OH) breaks the dirt down into less adherent surfaces.

3. The rainwater expands on the surface, generating an extremely fine layer that cleans and removes the dirt broken down by the active oxygen.

One of the main sources of atmospheric pollution, which really threatens human and environmental health, are NOx (nitrogen oxides as combustion by-products) from vehicles, heating and some industrial processes. The active oxygen (–OH, O2–) produced by the Bios Self-Cleaning® facings oxidises the NOx into non-harmful substances (NO3– water-soluble nitrate), which are washed off by rainwater. The NO3– oxidised by the photo-catalytic reaction is too little to have any influence on soil acidification. The guaranteed NOx-reducing properties of Bios Self-Cleaning® make an appreciable contribution to the improvement of the environmental standards of urban settlements. Just think that a 1000 sqmt Bios Self-Cleaning® facing can purify the air like a wood the size of a football pitch or remove the nitrogen oxides (NOx) emitted by 70 cars during one day.

A number of strict lab tests proved that the efficiency of Bios Self-Cleaning® does not diminish over time. The durability of the ceramic slabs has been confirmed by an accelerated aging test, the conditions of which were comparable to 50 years’ outdoor exposure. 

The Bios Self-Cleaning® process is completely natural, as well as ecosustainable, because it uses solar energy to activate the photocatalytic reaction, while exploiting the washing action of rainwater to remove dirt. The main cause of deterioration of building façades in urban and metropolitan environments is attributable to the concentration of organic deposits (oily stains, dust, soot) generated by oils and exhaust gases emitted by motor vehicles, boilers for heating and industrial systems. Thanks to the Bios Self-Cleaning® treatment, these deposits are first broken down naturally and then easily removed by rain, thus drastically reducing the cleaning and maintenance operations required for the surfaces and therefore saving both money and resources.

A series of stringent laboratory tests have shown that the performance of Bios Self-Cleaning® remains constant over time. The durability of the treatment has been confirmed by subjecting the ceramic tiles to an accelerated ageing test in conditions equivalent to 50 years of exposure outdoors. The Sunshine Weather Meter is a testing instrument commonly used in Japan to predict the duration of products. The field test conditions (temperature, humidity, intensity of UV rays and washing effect of the rain) are recreated artificially and varied so as to faithfully reproduce the surrounding environment. As regards tread resistance, it is important to point out that the Hydrotect® technology incorporated into the ceramic surface at the firing stage of the industrial production cycle is able to maintain its characteristics over time, complying with the measures relating to stress from light foot traffic and the pertinent maintenance indications.

The use of Bios Self-Cleaning® on ventilated façades and cladding poses no risk to human health or to the environment, either during the manufacturing and application processes or for the end users: Titanium dioxide is a natural, completely harmless substance. In turn, the photocatalytic process purifies the air, freeing it from polluting agents (NOx). Because the amount is small, the NO3 - oxidised by the photocatalytic reaction have no influence on soil acidification, so the substances are not harmful for either human health or the environment.

The performance of the Hydrotect® technology Bios Self-Cleaning® is based on is certified according to the most important international standards. To ensure the certified performance is maintained, all manufacturers who have obtained the licence for the use of Hydrotect® technology are continually monitored by TOTO to verify that the quality of the treatments remains constant, and that the cycles are developed and updated based on the research conducted and best practices acquired from applications worldwide. In addition, through the Master Agreement with TOTO, Casalgrande Padana is the first Italian company to be admitted to the exclusive international network of Hydrotect® partners, created to aid the exchange of experiences and innovation among global players from a wide variety of industrial sectors that use this technology.

The large formats and the wide range of Casalgrande Padana porcelain stoneware tiles allow for the creation of extremely versatile solutions for designers, architects and interior designers to freely express their idea of architecture using different formats, finishes and colours every time, in a wide variety of settings and application conditions. Ventilated façade systems are mainly used for public and service buildings, shopping malls, office buildings and industrial complexes, but they are also found on residential buildings, in areas of intervention where the purpose of maintaining aesthetic and technical architectural characteristics over time is to enhance their overall beauty. An effective, practical and ecological response comes from the world of ceramics, with the Bios Self-Cleaning® treatment, available on request for all the series in the catalogue, including “on demand” products.