We propose a method that eliminates speckle artifact in the reconstruction of triangular mesh based computer generated holograms. The proposed method generates a number of holograms with different sets of interleaved plane carrier waves. The generated holograms are displayed sequentially with time-multiplexing, achieving speckle-free reconstruction without sacrificing the viewing angle or depth of focus. The proposed method is verified experimentally using viewing-window type holographic display setup. The experimental results indicate that the proposed method can achieve speckle-free reconstruction with smaller number of the time-multiplexing than conventional temporal speckle averaging techniques.