Abstract: A technique for the design of 3-D RF welding electrodes by first modeling the surface of the welded part perimeter as a spline in a 3-D CAD program, and then dividing the spline up into multiple, small straight segments. The straight segments are offset simultaneously in opposite directions from the spline, to form two sets of straight segments, each set being equidistant from the spline, with the gap between the two sets equal to the target thickness of the welded package. New die faces are constructed from each of the sets using smoothing techniques, and 3-D models of the die faces are manufactured to check accuracy of the design, making sure that all the corresponding points of the pair of electrodes are equidistant, thereby creating a strong weld with good cosmetic results all along the parts being joined.

Abstract: A practical method to increase the fusion of radio-frequency welds between two structures made of dissimilar materials by introduction of a bonding layer between the two structures. The bonding layer must be an RF-weldable material that welds or bonds well to both of the materials from which the respective structures are made. The bonding layer may be introduced by coating one of the structures with the bonding material or by forming the bonding material into a sleeve which is placed over one of the structures.

Abstract: Methods of joining two structures made from dissimilar polymeric materials involve applying a coating containing a polymeric resin, such as a polyurethane-based polymer, to at least a portion of the first structure and welding the second structure to the coated portion of the first structure.