A vertical form-fill-seal the film approaches the back of a long hollow conical tube, which is called the forming tube. When the center of the plastic is near the tube, the outer edges of the film form flaps that wrap around the conical forming tube. The film is pulled downward around the outside of the tube and a vertical heat-sealing bar clamps onto the edges of the film to create the “fin Seal”, bonding the film by melting the seam edges together.