Abstract: The several embodiments illustrated in the FIGS. show welding apparatus for joining a plurality of plies of laminar thermoplastic materials held in and by gripping apparatus such as clamp jaws or belts. The weld is made by locally melting said plies by heating their protruding edges to a determined degree and for a determined period of time. Heat is brought into close proximity to the melt area and the gripping means provides a cooling means for the gripped plies of film. The completed welds are then cooled. The welding apparatus may be applied to material plies to seal their edges, or to seal the plies intermediate their edges. The welding is also shown as produced by continuous means and a heated ribbon may provide the severing means.

Abstract: This invention discloses a packaging apparatus and method for large size products such as subprimals of meat. The products to be packaged are characterized as often having irregular surfaces and voids which make sealing of the film without wrinkles very difficult, particularly after bringing to a condition of reduced pressure. There is shown apparatus for forming a drape of film from two rolls of film and into this drape of film is advanced the product to be packaged. This drape is formed into a tubular film around the product and with this tube open at both ends. Into these open ends of the tube are moved spreader probes or bars which operate as pairs and are moved away from one another by a pneumatic cylinder which is actuated by appropriate apparatus so that the spreader probes as they move apart cause the film in these ends to be brought to a narrow opening and under a slight stretch. This elongated opening is substantially equally spaced from a theoretical center line of the tubular film.

Abstract: This invention discloses a packaging apparatus, method and the resulting package for large size products such as subprimals of meat. The products to be packaged are characterized as often having irregular surfaces and voids which make sealing of the film without wrinkles very difficult, particularly after bringing to a condition of reduced pressure. There is shown apparatus for forming a drape of film from two rolls of film and into this drape of film is advanced the product to be packaged. This drape is formed into a tubular film around the product and with this tube open at both ends. Into these open ends of the tube are moved spreader probes or bars which operate as pairs and are moved away from one another by a pneumatic cylinder which is actuated by appropriate apparatus so that the spreader probes as they move apart cause the film in these ends to be brought to a narrow opening and under a slight stretch.

Abstract: The present invention pertains to the method for forming vacuum packaged products wherein a tear-inducing tab is provided for easily rupturing the film. This invention is particularly directed toward the wrapping of vacuum packages for packing meat and the like and in which the films used therewith are tough and not amenable to tearing. In this invention is provided a method for forming a flat, substantially inflexible tear tab member having a sharp point. This tear tab is laid on the product to be packaged with the sharp point portion thereof extending therefrom so that after the package has been formed the bending of the seal line of the package at or very near the extending portion of the tear tab causes the point of the tab to puncture the film to permit easy further tearing and eventual uncovering of the product.