By early 2018, Tianyuan Garments Co., based in the Suzhou Industrial Park in eastern China, will unveil a $20 million factory staffed by about 330 robots from Atlanta-based Softwear Automation Inc. The botmaker and garment company estimate the factory will stitch about 23 million T-shirts a year. The cost per shirt, according to Pete Santora, Softwear’s chief commercial officer: 33¢.