by Centro Ceramico *11
Maggio
2020
Ceramic Tiles or Plastic Based Materials flooring?
In recent years, a new family of flooring materials identified as Plastic Based Materials flooring (PBM flooring) has burst onto the market. The term Plastic Based Materials flooring refers to resilient and/or modular multilayer and/or laminate floor covering materials as specified in EN 14041 (2018) and which containing plastic. The following are some examples: Resilient Floor Coverings, Luxury Vinyl Tile (LVT), Luxury Vinyl Plank (LVP), Wood Polymer Composite (WPC) Flooring, Stone Polymer Composite (SPC) Flooring, Clay Polymer Composite (CPC) Flooring, Rigid Core Board (RCB), Engineered vinyl plank (EVP), Laminate, Multilayer flooring, etc.
PBM flooring materials are multi-layer and/or composite products, i.e. they are made from a combination of different types of organic and inorganic materials (Figure 1). The presence of an organic component gives these materials a series of finished product characteristics that are strictly dependent on their polymer content. To appreciate the consequences of this, it is useful to compare these materials with ceramic tiles(1) on the basis of the most important properties required of flooring materials today.
As shown in Figure 2, the characteristics requested by the market include aspects such as durability, user health and safety, and product end-of-life, in other words recyclability.
As ceramic tiles are inert materials of an inorganic nature, they are not themselves susceptible to the growth of micro-organisms such as fungi, mould or bacteria in normal conditions of use, and they are non-toxic. In the event of food contact, compliance with the CE marking ensures that Pb and Cd levels are below the legal limits. Ceramic tiles can be treated to help reduce indoor pollution, i.e. pollution inside homes or offices caused by emissions of volatile organic compounds likely to cause discomfort, in some cases seriously, to the people using those spaces.
The situation is different for PBM flooring materials because the presence of an organic component in the material’s composition facilitates microbial growth. This growth can be reduced/inhibited by adding chemical additives with anti-bacterial, anti-mould or anti-fungal properties. PBM flooring materials may contain and potentially release hazardous substances (e.g. formaldehyde, phthalates, pentachlorophenol, etc.), some of which are classified as carcinogenic and/or mutagenic. These substances may be present in the raw materials, they may be generated during the production process, or they may be introduced as additives to give the finished product specific characteristics (e.g. fire resistance, anti-mould, anti-bacterial, anti-fungal, anti-aging properties, etc.). If released, the hazardous organic substances potentially present in PBM flooring contribute to indoor pollution, the main cause of Sick Building Syndrome.
As for user safety, it is also important to remember that ceramic tiles are non-combustible, so in the event of fire they do not burn, emit smoke or contribute to the spread of flames. Furthermore, the slip resistance values of ceramic tiles measured using the DIN 51130 method (classified according to levels R9, R10, R11, R12 and R13) cover all slip resistance classes, which means that the most suitable product can be chosen according to the specific use.
By contrast, the plastic content of PBM flooring means that these materials are potentially combustible and may emit potentially acidic, corrosive and toxic fumes. The slip resistance values of PBM flooring measured using the DIN 51130 method generally fall into class R9/R10. Higher levels of slip resistance can be attained by performing specific surface treatments.
The presence of polymers in the composition of PBM flooring also plays an important role in terms of durability as it is responsible for:
(i) - thermal expansion coefficients at least an order of magnitude greater than those of ceramic tiles (≈ 60·10-6 K-1 for PBM flooring compared to ≈ 6·10-6 K-1 for ceramic tiles, which means that PBM flooring expands 10 times more than ceramic tiles for the same temperature increase). PBM flooring requires special care during installation and is not always recommended for use on floors with underfloor heating or in areas near radiators;
(ii) - potential discolouration effects caused by light radiation which are often not covered by the product warranty. PBM flooring is normally recommended for indoor use. The reference service life depends on the EPD of the individual manufacturer and is generally not longer than 30 years;
(iii) - potential sensitivity to organic solvents, chemicals and staining agents. Due to this sensitivity, PBM flooring may display surface effects such as swelling, colour variation, loss of shine, delamination and the presence of indelible stains;
(iv) - high susceptibility to scratching, with Mohs scale hardness values as low as 4 (fluorite);
(v) - potential deformability under loading from wheels (wheelchairs, trolleys, etc.), furniture (wardrobes, tables, chairs, etc.), stiletto heels, roller skates, etc., causing indentation damage on the surface.
In product warranties for PBM flooring, points (i) - (v) are often restricted and/or excluded, indicating a certain vulnerability of these products to the above-mentioned aspects.
Ceramic tiles are thermally stable due to their intrinsic characteristics and have a coefficient of thermal expansion of ≈ 6·10-6 K-1, making them suitable for use on floors with underfloor heating or in areas close to radiators.. Ceramic tiles have a reference service life ≥ 50 years (as indicated in the sector EPD published on 26 September 2016 and available online at the link https://ibu-epd.com/en/published-epds/). Their surface is:
(i) - resistant to organic solvents;
(ii) - resistant to chemicals and stains in accordance with EN ISO 10545 part 13 and part 14;
(iii) - scratch resistant, with Mohs scale values ranging from 4 (fluorite) to 8 (topaz);
(iv) - neither deformable nor susceptible to damage under loading from wheels (wheelchairs, trolleys, etc.), furniture (wardrobes, tables, chairs, etc.), stiletto heels or roller skates.
Last but not least, the product’s end-of-life is an aspect that further differentiates PBM flooring from ceramic tiles. PBM flooring is more difficult to recycle than ceramic tiles. As with all multilayer and/or composite materials on the market, post-consumer recycling is highly complex as it involves separating the layers and/or individual components. Waste-to-energy treatment (i.e. incineration to obtain heat for use in other production processes such as energy production) may give rise to emissions of harmful substances (dioxins, greenhouse gases, etc.) depending on the content and nature of the organic component. The feasibility of recycling solutions for PBM flooring is not currently documented scientifically.
By contrast, the fact that ceramic tiles are homogenous products made from inert natural materials (clays fired at high temperatures) means they are recyclable. Recycling can be performed on a post-consumer basis or during production in the case of production waste or products that are not suitable for sale. The feasibility of the various recycling solutions for ceramic tiles is documented scientifically.
When choosing a floor covering material, it is important to opt for a safe and well-known product such as ceramic tile, which has always been part of our building and living tradition, rather than being tempted by products whose chemical, physical and performance characteristics are highly dependent on their plastics content.
(1) The term ceramic tiles refers to tiles that comply with ISO 13006 or EN 14411 standards and the related test methods (EN ISO 10545 parts 1-16).