F O C U S The paper provides details of the degree of double bond conversion of the surface at varying UV-parameters. Conversion at the surface is almost complete over a wide process window. At intensity values above 500mW/cm2 and above a dosage of 200mJ/cm2, there are no unreacted double bonds and almost total conversion is attained at lower intensities around 200mW/cm2. Double bond conversion on the underside showed complete cure over the whole process window. Scratch resistance is the most important attribute of the cured UV film and the superior performance is due to the hard and elastic network formed during cross-linking. There are several tests that are applied to measuring the scratch resistance of clear coats, and the most common test is referred to as the Amtec-Test, which is a bench top car wash simulation test. Panels are subjected to brushing cycles with an abrasive medium. The gloss level of the coating is measured before and after the test and the percentage of residual gloss indicates the degree of scratch resistance. Tempering of the coating by reheating for one hour at 60°C promotes a self-healing effect and the reflow efficiency can be monitored. Test results are shown graphically in this paper. Excellent gloss levels are achieved across the curing window with gloss levels before reflow of above 90% for all curing conditions. After reflow the residual gloss reaches nearly 100% indicating that no loss of gloss occurs due to the car wash simulation scratch testing. This excellent film performance is due to the elasticity of the crosslinked coating, which allows quick elastic recovery of the coating during the scratch test. Polymer chains deform and dissipate the force of the brush. When the stress is removed, elastic recovery occurs and the scratch disappears. Other scratch testing details are described in the paper.
DECEMBER 2008
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POWDER
Examination of the shadowed areas showed that the UV dose and intensity levels could be lower than the values indicated previously. It has been proved that coated areas cured with low UV intensity are more susceptible to oxygen inhibition than areas with low UV dose. The UV intensity decreases with increasing distance from the source and is, therefore, varying spatially for the irradiation of complex-shaped objects. However, the high conversion of double bonds even at low intensity levels enables the cure of complicated three-dimensional substrates with shadowed areas. The paper concludes that the UV-powder technology delivers both the environmental and coating properties demanded in today’s and tomorrow’s high technology applications. Paper entitled “UV-Powder Clear Coat – An Ecological and Technological Benchmark” by Dr Carmen Flosbach of DuPont Performance Coatings GmbH, Germany, presented at the Fatipec Congress 2008 in Ghent, Belgium on 9-11 Jun 2008. Copies of the Congress papers available in CD format
INDUSTRY NEWS Coatings: Inver acquires Beckers’ European operations Italian company Inver (which specializes in industrial liquid and powder coatings) has acquired the European powder coatings operations of Swedish company AB Wilh Becker (Becker Powder Coatings). The deal includes 4 production sites (in Thouars, France; Aquila, Italy; Liverpool, UK; and Debica, Poland). Becker Powder Coatings’ French and UK businesses rank third and fifth respectively on their markets. The acquisition will enable Inver to create a competitive platform on the European market for this type of coating. Beckers’ Polish operations will significantly strengthen Inver’s position on the
C OAT I N G S emerging market in Poland. The country is currently the leading producer of powder coatings (in terms of volumes) of the former Eastern bloc countries, accounting for 33% of production. Beckers’ Italian operations (coatings for aluminium for construction applications) will consolidate Inver’s position on its home market. Furthermore, the acquisition will double Inver’s powder coatings business making it the fourth largest producer in Europe, and will increase the share of its powder coatings on turnover to around 55-60%. Inver and Becker Powder Coatings will establish an integration plan for the 4 acquired production facilities, which may include a restructuring of the plants in order to introduce new production processes and expand capacities. Inver has no plans to cut jobs at the facilities. Meanwhile, Beckers is to focus on its core businesses: industrial coats, wood coatings and paints for artists. Chimie Pharma Hebdo, 13 Oct 2008, (440), 11 (in French) & Farbe und Lack, Nov 2008, 114 (11), 8 (in German)
AkzoNobel to supply coatings for McDonald’s restaurants AkzoNobel has developed a new coatings menu for McDonald’s and will supply a range of paint products for the redesign of hundreds of Purely Simple restaurants. The agreement was established through AkzoNobel Global Image Solutions (GIS), which specializes in offering a “one stop shop” to customers who are looking for a range of different coating products from AkzoNobel’s coatings portfolio. The company’s powder coatings will be used on the furniture of Purely Simple outlets throughout Europe. The coatings will be resistant to the intensive cleaning that takes place for all surfaces in McDonald’s restaurants. Het Financieele Dagblad, 15 Oct 2008, (Website: http://www.fd.nl/) (in Dutch)
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