*Part of an occasional series highlighting the importance of surfaces and particularly the outermost few nanometres in determining the key properties of commercial products.This series arose from an original article highlighting the Surface Coatings Community in the UK. See also The Importance of Surface Coatings in the Marine Industry and The Importance of Surface Engineering and Coatings to UK Industry and Wealth
The market for flat glass has recently been forecast at $134 billion by 2023 with increasing demand in the construction, architectural and automobile industry driving demand coupled with specialist applications in photovoltaic cells and thermal collectors. An ongoing CAGR of over 6% is expected as more cars are produced and architects specify greater use of glass in residential and commercial buildings. Major players such as NSG, St Gobain, Asahi, Corning and Schott are experimenting with new technology in solar control and solar energy, noise control, thermal insulation and safety glass. There are thought to be only a few hundred float glass plants in the world operating continuously around the clock each producing up to 6000Kms of glass per year. Increasingly the product properties are being refined on line or in some cases off line with post treatments to meet sophisticated demands of customers and allow a wider range of coatings.
It is interesting that such a high volume continuous production product often seen as a commodity has developed into a sophisticated surface modified, multi-layer, high specification material where some of the latest nanotechnology tools are being employed. In some applications, multiple layers nanometres thick are being deposited at glass surfaces by techniques such as chemical vapour deposition to impart a variety of properties to a high-volume product. Indeed, the speed of production and tolerances required in such processes place the industry at the forefront as one of the most proficient developers and users of nano-deposition and on-line monitoring techniques.
An interesting application of surface modified technologies is in the area of self-cleaning glass. This is based on original work carried out in the 1970`s and 90`s leading to the discovery of the photocatalytic properties of Titanium Dioxide. About 20-30nm of titanium dioxide in the anastase crystalline form are deposited at the surface of the glass by chemical vapour deposition or, in some cases, magnetron sputtering. When exposed to ultra-violet from sunlight a photocatalytic reaction occurs breaking down organic matter/dirt and creating a hydrophilic effect at the surface. Rain water falling on glass will normally form droplets as glass is typically hydrophobic in nature however the effect of the coating is to disperse the water across the glass having a cleaning effect.
The ability to deposit nano-layers of surface coatings on glass greatly expands the range of properties exhibited and has allowed multiple new applications in construction, automotive and display technologies. Self-cleaning glass has the effect of reducing the level of maintenance required in residential and commercial high-rise buildings. Not surprisingly there is a similar low maintenance requirement for the aluminium window frames which hold the glass and again are specified by architects. The painted frames must survive extremes of temperature from the cold of Northern Canada to the elevated temperatures of the Gulf States.
Powder Coated Aluminium Window Frames are very durable and often specified by architects as a low maintenance and weather resistant option in construction. Similar external building features which enhance the appearance of the building are also powder coated. Major powder coating manufacturers have decades of weathering data providing certainty and assurance for installation in high-rise and other buildings where regular maintenance may not be feasible. Although many of us are familiar with traditional solvent or water based coatings, the advantages of powder coating; the powder coating process and powder coating properties are less well appreciated. Powder coatings have an inherent environmental advantage as they are applied without a carrier or solvent, are thicker films and, in some cases, offer a greater range of film properties depending on whether the product is thermosetting or thermoplastic.
For thermosetting powders product is blended with both binder, pigment and a range of additives, including flow agents and U.V. stabilisers before being melt mixed and micronized into a fine powder. The powder is then electrostatically sprayed onto an earthed substrate and cured in an oven. Reaction with the crosslinker occurs and the powder flows to form a paint film. The flow of the material is important to minimise the orange peel effect common in powder coating finishes.
Thermoplastic powder coatings rely on heating the powder above the glass transition of the material to facilitate formation of the paint film. Manufacture of such coatings sometimes requires cryogenic milling to create the micronized powder. Such products often have more flexibility and impact absorbing properties and may be used in other construction products such as fencing. Architectural products are expected to be robust, UV resistant, long lasting and be low maintenance over extended periods in huge temperature ranges.
High value residential and commercial property ventures are critically dependent on the surface coatings community to ensure a crisp finish and longevity of appearance.
X-Ray Photoelectron Spectroscopy (XPS) is a powerful surface analysis technique which is capable of detecting and mapping the distribution of additives such as biocides at the surface, subsurface or through a cross section of a paint film.
Contact Sciencia Analytica for your surface analysis needs.
0151 296 1433
According to a new study by Global Market Insights*, the global powder coatings market is forecast to exceed 3,800 kilo tons by 2023, growing at a CAGR of 6.8 percent. The analysis predicts revenue of $15.58 billion by 2023. As well as architectural applications powder coatings are used in multiple sectors.
A strong automotive production outlook in China, Brazil, Malaysia and Germany is expected to drive powder coatings market size across applications including door handles, rims and under-the- hood components. Since 2012, when automotive production was close to 84 million units, the industry has witnessed over 10 percent growth every year with applications that include wheels, radiators, bumpers, shock absorbers, engine blocks, coil springs and mirror frames. Automotive powder coatings market size was estimated at over 460 kilo tons in 2015, and growth of 7.4 percent is expected by 2023.
A growth in sales from domestic appliances including washing machines, freezer cabinets and microwave ovens should also spur growth in the industry. Metal cabinets, parts of office chairs, shelving systems, and outdoor metal furniture are other attractive avenues for industry participants, with a revenue forecast of $2.93 billion by 2023, at 7.8 percent CAGR. The introduction of medium-density fiberboard (MDF) over the years has intensified the market for powder coatings on wood furniture. Consumer goods have been a high volume application, accounting for over 22 percent of the powder coatings industry share in 2015. Refrigerators, dryer drums, washer tops and lids, AC cabinets, water heaters, vacuum cleaners, range housings, dishwashers, microwave cavities, and freezer cabinets are frequent products using powder coatings.