This paper proposes a 3D printable polylactic acid (PLA) lens to reduce the beam divergence of dual-mode OAM beams generated by a uniform circular array (UCA) at 5.9 GHz. The lens is placed in front of the UCA to modify the phase of the OAM beam, which results in a reduction of beam divergence. The UCA generates OAM modes l=+1 and l=+2 by providing input excitation to the individual feed network. The effectiveness of the PLA lens is compared to the UCA antenna with and without the lens in terms of the radiation pattern, S11, electric field amplitude, and phase pattern. The radiation pattern of the OAM beam with the PLA lens exhibits a more focused and narrower beam than the OAM beam generated without the lens. The proposed PLA lens could be used in future OAM-based communication systems to reduce beam divergence and improve communication range.