APPARAT FOR APPLICERING AV RORFORMIGA, VERMEKRYMPBARA, TERMOPLASTHYLSOR TELESKOPISKT PA ARTIKLAR

摘要

The present invention relates to improved apparatus for forming a tubular plastic sleeve immediately prior to its application to a rigid base article, such as a glass or plastic bottle. A rectangular blank of plastic material is wrapped around a cylindrical mandrel and seamed lengthwise thereon to form the tubular sleeve. The mandrel has a plurality of spline-shaped grooves in its curved peripheral surface and a stripper ring mounted to closely surround such peripheral surface to be slidable thereon. The ring has a plurality of internal lugs which slidably fit within the spline-shaped grooves. The mandrel has a lineal array of vacuum ports for retaining the leading and trailing edges of the plastic blank on the mandrel for its wrapping thereon, and an axial resilient strip mounted in the curved peripheral surface of the mandrel for operation of a movable, axially-extending sealing bar thereagainst. A wedge-shaped expansion member is also mounted in a wedge-shaped channel or groove in the mandrel peripheral surface between a pair of spline-shaped grooves. The expansion member is adapted to be moved vertically with respect to the mandrel for contraction of the mandrel diameter to release the newly-formed sleeve for its removal therefrom. The sleeve is then applied to a glass or plastic bottle for heat shrinking thereon in a thermoconstrictive operation. The apparatus is especially adapted to forming a wide range of thicknesses of a variety of heat-shrinkable thermoplastic materials into suitable tubular sleeves for telescopic mounting on such containers in a rapid, efficient manner.