Abstract: In the fabrication of a plastic sleeve by heat sealing overlapped ends of a plastic film blank wrapped around a mandrel, a part of the underlying overlapped end is often melted inadvertently and adheres to the mandrel, obstructing easy stripping of the sleeve off the mandrel. Accordingly, a tensioning groove is formed in the mandrel surface, and a pressing-in bar is pressed thereinto over the sleeve while a part of the sleeve is held stationary against the mandrel by a holding plate to pull the sleeve part thus adhering sidewise in the peripheral direction of the mandrel and thereby to peel away and free the same.

Abstract: A plastic sleeve is fabricated by: winding a blank of plastic film around a hollow cylindrical mandrel having a groove of arcuate cross section extending in the mandrel axial direction along the mandrel outer surface and having numerous through holes through its wall including the concave surface of the groove, the blank ends being overlapped; applying a vacuum through the holes to the inner surface of the blank thereby to draw it by suction tightly against the mandrel outer surface; heat sealing the overlapped ends of the blank thereby to form a sleeve; and vitiating the vacuum and applying pressure above atmospheric to the inner surface of the sleeve thereby to facilitate the succeeding step of stripping the sleeve from the mandrel and fitting it on a glass bottle.