Abstract: Methods and apparatus for blow-molding hollow articles from open-ended tubular bodies of thermoplastics material include dimensionally expanding the open end of the tubular body to accomodate a blow pin plate of preselected dimension and/or geometry. The expanded open end of the tubular member will thus be closed by the blow pin plate. Subsequent introduction of pressurized fluid (e.g., air) into the tubular body through the blow pin plate will cause the tubular body to conform to the female cavity which envelops the same. In such a manner, hollow articles having relatively large sized and/or irregular shaped openings may be fabricated utilizing blow-molding techniques.

Abstract: Methods and apparatus for blow-molding hollow articles from open-ended tubular bodies of thermoplastics material include dimensionally expanding the open end of the tubular body to accomodate a blow pin plate of preselected dimension and/or geometry. The expanded open end of the tubular member will thus be closed by the blow pin plate. Subsequent introduction of pressurized fluid (e.g., air) into the tubular body through the blow pin plate will cause the tubular body to conform to the female cavity which envelops the same. In such a manner, hollow articles having relatively large sized and/or irregular shaped openings may be fabricated utilizing blow-molding techniques.

Abstract: Apparatus and a related process for blow molding an ultra thin plastic film bag in which sufficient heat is generated in the process to form an effective heat seal or weld along an edge of the bag. The blow mold halves are provided with laterally aligned, outwardly extending projections intermediate upper and lower edges of vertical parting wall surfaces of the mold halves. The projections and cavities formed above and below the projections are configured so that the temperature of the plastic during blow molding and pinch off above the melting point of the plastic to heat seal an edge of the bag. The invention also provides an ultra thin film plastic bag formed with a heat sealed bottom seam.