Ultrasonic Welding of Amorphous and Semi Crystalline Materials

Abstract

Ultrasonic welding have been studied using Polycarbonate (amorphous) and Polypropylene (semi-crystalline) in presence and absence of polymeric compatibilizer. A solution phase compatibilization has been used using Polycaprolactone, Polymethylmethacrylate and Maleic anhydride grafted Polypropylene. Cylindrical samples were used in the near and far field ultrasonication in order to achieve the better weldability. The welding strength was increased while utilizing the compatibilizer than that of un-compatibilized samples. Mixture of Polycarbonate and Polymethylmethacrylate on the PC phase enhanced the weld strength tremendously. The XRD analysis revealed the increase in crystallinity during the ultrasonication process resulting the enhanced weldability. The phase fusion is quite prominent from the SEM study of the fractured surface and also from the SEM of the welded portion. The FTIR study indicated the phase interaction through the compatibilizer thus enhancing the ultrasonic weldability of the thermoplastics.