This work was conducted to determine if there were any benefits with orbital vibration welding compared to linear vibration welding. The experiments were conducted using standard full-factorial designs with each process and each material. Four materials, polypropylene/polyethylene copolymer (PP/PE), polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) and Nylon [PA), were studied with each process. The equipment used was a modified Branson VW-4 with an orbital head that had isolated magnets. The same machine was used to weld with both linear and orbital motions. This was achieved by modifying the controlling parameters of the drive. It was found that compared to linear vibration welding, orbital welding had a reduction of cycle time by 36% and 50% in Phase I and Phase 111, respectively. It was also found that orbital welding dissipated 56% and 100% more power than linear vibration welding in Phase I and Phase III, respectively. In addition, it was seen that orbital welding was able to universally join unsupported walls with higher strengths and better consistency compared to linear welding. Other benefits included: a difference in the appearance of weld flash and small increase in weld strength. Some of the limitations of orbital welding that were identified included the effects of disengagement and residual stresses. POLYM. ENG. SCI., 49:1410-1420, 2009. (C) 2009 Society of Plastics Engineers