Injection moulded cover parts and window lenses must resist scratches and wear, and they need to fulfil demanding optical requirements as well. LITEONMOBILE introduces an improved hardcoating solution that is sprayed on the outer surface of the cover part or plastic lens after moulding.
The result is a plastic part that has superior scratch and wear resistant characteristics. The big touch-sensitive displays of touch screen phones are a good example of parts that require superior resistance during daily use.
Hardcoat can be sprayed (or dip-coated) on the surface of window or cover parts, the process being similar to UV paint or lacquer processes. Hardcoat is needed to maintain the colour, gloss, transparency and physical properties of plastic parts. At the same time it enhances the properties of wear and scratch resistance.
Project Manager Esa Muukkonen says that during the development period the hardness and scratch resistance values of different hardcoat materials were determined with pencil (ISO 15184) and scratch tests (ISO 1518) in addition to vibratory wear and optical tests. The test results indicated that hardcoat materials can really improve the surface hardness and scratch resistance of plastic parts. An optimized hardcoat process together with carefully selected hardcoat materials is the "recipe" for a successful hardcoat system. A hardcoat layer thickness is typically 5 – 25 microns, which is enough to offer superior scratch and wear resistance, while also ensuring that the layer is thin enough to give a certain degree of flexibility without cracking during normal use.
Hardcoating can be high gloss or matt, depending on the requirements, and is suitable for different plastics (PMMA, PC and ABS+PC), and also for products with a 3D geometry. A hardcoat solution for lenses and flat windows has been in mass production since 2005 with LITEONMOBILE, so we already have a lot of experience of this technique.
- Demand for hardcoatings on plastic mobile phone parts is growing rapidly. LITEONMOBILE will have an improved sprayed hardcoat solution for plastic 3D cover parts will be in mass production during 2010-2011, Esa Muukkonen states.