Abstract: An apparatus for forming a smooth, even, substantially encapsulating layer of a heat shrinkable polyolefin plastic on a glass container. The body of the container is substantially greater in diameter compared with the neck. A cylindrical sleeve of polyolefin is telescopically placed along the outer surface of the container and the two are conveyed together into a heating oven for shrinking the sleeve snugly over the container. During heating, the polyolefin initially softens and becomes limp such that the sleeve tends to fold over or upon shrinking creates wavy top margins on the shrunken covering. The apparatus provides controlled rotation of the bottle and sleeve in the oven to apply a centrifugal force to the limp plastic which remains erect and billowed outwardly to give the material time to react with the heat such that the sleeve material shrinks into overall even, snug contact about the contour of the container without folds and wrinkles.

Abstract: There is disclosed a method of covering glass containers with a preformed, cylindrical sleeve of a polyethylene or like polyolefin material, or laminates of polyolefins, that are heat shrinkable circumferentially of the sleeve and made from sheet of a foam or a laminate of said plastic material such as a foam-film laminate. Upon application of heat, the sleeve initially softens or becomes limp, and grows or enlarges, such that in its telescopic assembly on the upright bottle it tends to slip from position. The method includes supporting the sleeve from underneath during heating it for shrinkage by conveying the container and sleeve over a water-cooled sleeve support bar extending into the heating device a substantial distance allowing the sleeve to shrink onto the bottle. The sleeve support bar includes a lubricious surface layer adjacent the sleeve. The lubricious layer combined with water cooling maintains support surface below 200.degree. F, preferably below 150.degree.

Abstract: There is disclosed a water cooled support bar comprised of a pipe within a pipe which assures the axial position of a cylinder-like sleeve of heat shrinkable foam thermoplastic material on a glass container during transport from an assembly station on a turret machine into a tunnel-type oven and until the thermoplastic sleeve shrinks sufficiently snugly onto the container to be held thereby. Polyethylene material, and perhaps other polyolefins, have the tendency to become more pliable and grow or enlarge under heat prior to actually shrinking. It is during this initial heat-up time the invention serves to retain the sleeve form in place on the container. The support pipe includes a Teflon or like lubricious surface layer at least along the side thereof adjacent the plastic sleeve lower edge. The lubricious surface layer combined with water cooling prevents sticking of the plastic on the support bar.