Application Of Ultrasonic Welding In Backlight Plastics

This Article mainly analyze the existing lamp block process and its shortcomings based on the introduction of the principle of liquid crystal display, the role of backlight and structure of lamp block, and further put forward the subject of ultrasonic plastic welding.For ultrasonic plastic welding, this article introduces the development of ultrasonic welding, application areas and welding forms .It analyzes the ultrasonic solderability of different types of plastics as well . Further more, the theory of energy conversion for ultrasonic plastic welding is studied and the energy conversion formula is inferred on the basis of viscoelastic mechanics theory and simplified model of ultrasonic plastic welding.The lamp block needs to make some design change after the analysis of the design principles of ultrasonic welding interface and welding quality influencing factors. Three ribs which can guide energy are laid on the white reflector sheet; accordingly, three grooves are designed on the black part. We further decide the figure and dimension of the ribs and grooves on the basis of ultrasonic welding principle, and its feasibility and suitability are verified by the welding experiment.In this article ,The welding machine structure,operation instruction and process preparation items which are utilized for the Topic are introduced .The analysis result shows that all of welding time,welding pressure and keep time have influence on the welding quality, and the three parameters are defined the range by the ultrasonic welding theory and energy conversion formula figured out in previous chapter.The backlight plastic parts have had a try run on the welding machine, and the problems found during the try run have been analyzed and solved. Till now, the ultrasonic plastic welding process have succeed in mass production too, it has brought a great benefits, such as better yield,higher capacity and lower cost of equipments.