Self-Cleaning (EzyClean) Glass:
EzyClean is an optically clear protective coating that chemically bonds to the glass surface, creating a non-stick barrier resistant to corrosion, etching, and staining. However, while cleaning is made easier and less frequent, the need to clean is not eliminated. Treated glass becomes both hydrophobic and oleophobic (water and oil repellent) protecting against most forms of dirt and grime. The EzyClean molecule is highly resistant to chemical breakdown by UV light giving it long term stability. This protection thereby reduces staining and etching that often forms on shower recesses, kitchen splash-backs, exterior glass, railings, curtain walls, facades, windows, and other areas where glass is subjected to harsh conditions. EzyClean eliminates the need to use harsh and often toxic cleaners. In all but the hardest water areas, all that is needed to keep the surface clean is a simple wipe with a damp microfiber cloth and a mild detergent.
EzyClean is a low molecular weight coating carried by an Isopropanol (IPA) base. IPA allows better wetting and spreading on the substrate, which leads to a more complete coverage. Unlike a weaker hydrogen bond used by other products, EzyClean forms a strong chemical (covalent) bond with the surface. Cross-linking takes place to modify the surface’s properties. As it cures a network of minute brush-like filaments cover the surface. Thus, as no cohesive film is formed, no flaking or peeling can occur. Once curing is complete, the molecules of the coating are chemically inert. A permanent* bond is created, meaning that EzyClean can only be removed by abrasion, strong acids or alkalis, or the removal of the top layer of glass surface. This distinguishes EzyClean from most other products on the market that quickly wear out over time.
The EzyClean coating bonds to the microscopic hills and valleys of the glass (Fig. 2) as opposed to filling them in like some competitive products (Fig. 1). An advantage is that the glass is less slippery and easier to handle. Furthermore - silicone, seals, clamps, and suction lifting devices are able to adhere to the surface. Competitive coatings that fill in the surface reduce the ability for adhesives to create or maintain a bond, and require taping and/or edge deletion prior to application. As EzyClean does not require edge deletion it does not have this added labour cost to apply and remove these barriers. Figures 1 and 2 below illustrate the differences between EzyClean and competing products.
EzyClean can be applied to all types of smooth glass, including annealed or tempered glass. For tempered glass, the coating is applied after the tempering process.
EzyClean works by lowering the surface energy of the substrate which, in turn, increases the surface tension of a substance on it.
Surface tension is the cohesive ability of a liquid, or the amount of attraction of its molecules. Higher surface tension of a liquid means that it is more likely to coalesce into a sphere, such as water drops on a freshly waxed car. A low surface tension would thus have a flattening effect, such as oil poured into a pan. Surface tension results from an imbalance of molecular polarity. On the surface of the liquid, molecules are attracted to each other and exert a net force that pulls them together. High values of surface tension mean that molecules tend to interact strongly and create a sphere. Lower values mean the molecules do not interact as strongly and have a flattened profile. Surface energy is a solid surface characteristic associated with the molecular forces of its interaction with another material. The higher the surface energy is, the more likely it will be to overcome the surface tension of a liquid. Untreated glass’ surface energy is high enough to cause a water drop to spread into a film, as opposed to a bead. By applying EzyClean, the surface energy is reduced and water and oil tend to de-wet the surface.
Contact angle is a measurement of the behaviour of liquids in contact with the surface, defined as the difference in angle between the two. The ASTM (American Society for Testing) procedure requires a precisely measured droplet of water be placed on the surface. The surface energy of the substrate controls whether the droplet tends to stand up or flatten out. This is quantified by measuring the contact angle of the droplet with the surface using a Goniometer. Clear float glass treated with EzyClean has contact angles of between 100° and 110° whilst treated sand blasted glass is between 115º and 125º (the contact angle becomes greater with increasing surface roughness).
Figure 3: Contact angle measurement of water on sandblasted glass.
For the construction industry, EzyClean has been shown to significantly reduce the etching caused by cement render splashing during construction. The coating also allows easier removal of the cement during the clean-up period of the glass surface. The coating is ideal for sand blasted and acid etched glass, providing the same easy-clean and protective qualities. It also facilitates easy removal of fingerprints and other marks that often detract from the appearance of these types of glass. For these rough surfaces, the coating must be spray applied as hand application can lead to streaking that is difficult to remove.
Why Hydrophobic is important
Hydrophobicity is the ability of a surface to repel water and water-based substances. In terms of real world items, vehicle windshields, exterior glass, shower or spa glass, tiles, fabrics, and paints can be made hydrophobic. By repelling water, many types of debris cannot remain on the surface, as the water carries it away. This significant reduction in contaminants on the glass makes it far less likely to become damaged, etched, or stained.
Why Oleophobic is important
Oleophobicity is the ability of a surface to repel oils. From our experience, oleophobic properties are extremely important for an easy-clean coating. In hard water areas, soaps react with the minerals in the water to form Calcium Stearate and Calcium Palmitate, both oily in nature. These, along with other water insoluble substances such as body fats adhere to hydrophobic-only surfaces making cleaning significantly more difficult, and can lead to etching of the glass. Reactions of this type will occur to a lesser extent in softer water areas, but still happen nonetheless. In our experience as a global supplier, we have found that non-oleophobic coatings fail in the field in a relatively short period of time without evitalisers.
Why EzyClean is important
Most current easy-clean coatings are either not oleophobic, or only moderately (and temporarily) so. EzyClean differs such that as with being water repellant, it will remain oil repellent for over 10 years with a single application. Because of these properties, EzyClean repels almost all known stains and contaminants that are likely to soil, stain, or etch a glass substrate.
Booster Products & Warranty
Many contemporary products offer a Lifetime warranty. The longevity of these are extremely variable, and are contingent upon booster products in the vast majority of cases. Neglecting to use the booster products may result in the coating failing in as little as 6 months, but more often after 18 months. EzyClean comes standard with a 10 year performance warranty for professional (factory, OEM, and certified applicators) application. The glass only needs to be cleaned periodically and will never require a booster product as long as the maintenance instructions are followed. Some competitor coatings must be regularly maintained using proprietary cleaning products that reapply a thin film of the original product to regain performance and maintain warranty. EzyClean customers are not required to use expensive booster products to maintain the warranty.
EzyClean’s 10 year warranty also commits to a minimum level of performance. This is based on the accepted industry standard for hydrophobicity, which is directly related to easy-clean functionality. Compared to competitive warranties, the surface will remain easy-clean for 10 years.
Immediately after application, EzyClean-treated glass may be taken off the line and stacked or loaded directly into storage magazines. It must be stored with a minimum of a 2mm air gap to facilitate curing. Two common options for spacing are plastic pegs or clip spacers, provided they have a very small footprint. While foam/cork spacers can be used, time must be allowed for the coating to bond with the glass. A minimum standing time of 2 minutes at 25ºC and 60% relative humidity must be observed before affixing the cork/foam to the glass. Colder temperatures or lower humidity will require a longer standing interval.
Treated glass may be packaged or wrapped within 5-10 minutes (at 25ºC and 60% relative humidity), of application, provided there is 2-5mm of air gap. Curing of the coating can still take place in the packaging.
RECOMMENDED CLEANING INSTRUCTIONS
EzyClean makes cleaning easier and less frequent; however it is recommended that the glass is cleaned regularly post application. Failure to follow the recommended cleaning instructions may result in damage to the coating and void the warranty.
Glass Shower Screens
A quick clean once a week or as required using water and a mild detergent* with a sponge or a good quality microfiber cloth, will remove soap scum and grime from the glass. The use of a high quality professional grade squeegee (such as Ettore or Pulex) may be used to dry the glass**, however it is not a necessity.
Glass windows, curtain walls, doors, pool fencing & glass railing, mirrors and splashbacks
Using a mild detergent* and water, wash the glass with a sponge/t-bar mop or damp good quality microfiber cloth, and dry the glass** with a high quality professional grade squeegee (such as Ettore or Pulex). For best results clean the glass in the shade to prevent streaking. In areas prone to salt or dust build-up rinse off excess contaminants with a hose using fresh water before cleaning (failure to remove these abrasive contaminants may damage the coating).
Do not to use any rough, gritty, highly acidic, alkaline or abrasive cleaners such as Comet (powder), Ajax, or cerium oxide as they may damage the protective coating. Cleaners like these damage or polish back the actual substrate of the surface. They are not required or recommended for use on EzyClean treated surfaces. In areas with hard or bore water, mineral deposits such as lime and calcium may build up on the protective coating and not be easily removed with a mild detergent*. A solution of white vinegar and water (1 part vinegar to 4 parts water) will need to be used occasionally to dissolve these deposits. If the lime scale is still proving difficult to remove use a more concentrated vinegar solution. Allow the vinegar solution to sit on the surface for 10-15 minutes to help dissolve lime deposits before cleaning as their abrasive nature may damage the coating.
Tips for extreme hard water conditions
Around the world there are some unique locations which have extremely harsh conditions. In these harshest of water environments, EzyClean is a great choice. Simply put if you didn't have the EzyClean protection, the glass may have to be restored to bring back the clarity or even replaced in as little as one year. New Orleans, Louisiana, some European countries, and Western Australia are examples of areas with very high mineral concentrations. Being so robust, the EzyClean coating is a great option in these conditions. It promotes great looking glass, but it takes a little more work due to these specific environmental conditions. In such environments minerals are so prevalent in the water that they can still create a build-up on the EzyClean coating. However, even over a very long time the minerals are not damaging the glass, although it can become difficult to remove. PCT Global recommends using the vinegar/water solution (listed above) every week or so as a cleaning option to reduce this build up on the surface, rather than allowing the build up to continue over a long period of time.
* A mild detergent such as dish washing liquid at a 0.5% solution 5g to a litre of fresh water is recommended.
** Do not use a squeegee on dry glass as this may damage the coating over time.