Short staple composite yarns are one of the newly emerging technologies with the greatest potential for Japanese yarn manufacturers. Short staple composite yarns can be produced using two different types of short staple material or by using short staple material and continuous filament material. The uniform blending of short staple and multifilament yarns consists of multifilaments that are opened electronically and then twisted or interlaced with short fibers. A composite yarn made from two kinds of short staple material (in the sheath and core) is called a double structure yarn. This product can be manufactured using a spinning draft or a roving yarn. However, a yarn with a filament core and a staple sheath is called a core spun yarn, and can be made using a drafting process. Multistructural yarns consist of at least three different materials distributed in a concentric pattern. A list of Japanese machinery patents, including a weft insertion device, yarn package control system, and fabric roll detection, is provided.