The T-shirt bag making machine is suitable for producing HDPE/LDPE T-shirt bag with and without printing. The machine is equipped with a photocell on each line, which helps to make sure of the printing area on the film. The machine can cut the bags at same length.The hot sealing/cutting knife makes the bottom welding of the bag stronger than other kind of bottom sealing machines. Since the raw material cost keeps increasing, many film producers are producing films from recycled material or CaCO3 blended material, which is more difficult to be heated/sealed. Polystar specially designs the hot sealing/cutting knife for the user who has films made from recycled material and CaCO3 blended material. The bottom of the bags can be well welded by this hot cutting system.