The mandatory use of face covering masks had an immediate and negative environmental impact, as the generalized adoption of disposable masks generated an enormous amount of additional plastic waste. The presence of polypropylene in these masks makes their degradation time very long, hence potentially affecting ecosystems in the case of improper disposal. Moreover, the effectiveness of face masks to fight against the spread of Covid-19 viruses has been questioned because of their non-tight fitting to the face and degradation of filtration efficiency overt time in the case of washable cloth masks.
Objective of Crystar® aFT
Using our knowledge in filtration technologies and porous ceramic materials, Saint-Gobain Performance Ceramics & Refractories joined a collaborative work with Pracartis and Bouverat-Pernat to create the Precimask®: an efficient, breathable and durable face mask to contribute to the barrier measures to fight against the COVID-19 spread. Precimask® is equipped with Crystar® air filters, which can be sanitized without losing their filtration efficiency and offer a shelf life of more than 40 years, hence strongly reducing the ecological impact related to the use of face masks.
Main benefits of Crystar® aFT
Saint-Gobain Crystar® developed a special, high porosity ceramic filter solution to provide a filtration efficiency equivalent to surgical masks (>95% retention of bacteria-inoculated aerosols with an average size of 3 µm, ref. EN 14683 AC. Combined with the enhanced air tightness of Precimask® masks, a high and reliable protection level is ensured.
|EN 14683 AC
(bacterial filtration efficiency)
|>95% of 3 µm aerosols||UNS1
Surgical Mask Grade 1
The breathability of the filtration solution was evaluated by pressure drop measurements. The table below exhibits the obtained results, expressed in terms of permeability and average pressure drop at specific air respiratory flow rates. Despite the excellent air tightness level of Precimask®, the low resistance of Crystar® aFT to air flow allows for a very good breathing comfort.
|Norm||Breathing Flow||Max. Pressure Drop For Class P3 filter||Filter Average Pressure Drop Precimask®|
Particle filters for half masks and respiratory protection masks
|30 l/min||1.2 mbar (120 Pa)||0.6 mbar (60 Pa)|
|95 l/min||4.2 mbar (420 Pa)||2.8 mbar (280 Pa)|
|Specification||Configuration||Permeability||Breathability Precimask® Filter Cartridges|
|30 l/min||Mask without window||>96 l/s/m2 at 100 Pa||380 l/s/m2 at 100 Pa|
|95 l/min||Windowed mask||>300 l/s/m2 at 100 Pa|
Thanks to its specific construction material, our innovative and patented filtration medium, can be easily cleaned and reused over and over, without losing any of its functional properties. With an adequate use and maintenance of the filters, its expected lifetime can reach several years, even several decades, hence generating a minimum of waste.
This major technological breakthrough is a great example of how Saint-Gobain Performance Ceramics & Refractories can offer its extensive knowledge in ceramic materials science to partner with its customers in the development of more sustainable solutions that can make the world a better home.