Apparatus controlling shrinkage of a sleeve wrap on a container

An apparatus for shrinking a plastic wrap on the exterior of glass bottles each having a neck finish, neck, and enlarged body and bottom end portions which comprises

• a plurality of said bottles having sleeves of heat shrinkable polyolefin plastic carried thereon, said sleeves being of a height substantially the height of said bottles,
• plural bottle chucks holding said plurality of bottles at their neck finish,
• a conveyor having said chucks spaced therealong and supporting said bottles at one axial end in a vertical depending position, said conveyor being guided through a horizontal path,
• an elongated oven means disposed along said conveyor path such that bottles and sleeves thereon pass through the oven means during movement of the conveyor in said path, said oven means furnishing heat for shrinking the plastic sleeves in surface engaging conforming relationship on said bottles, the improvement therein comprising
• a pulley connected to each of the chucks for rotating the bottles about a central vertical axis,
• an endless, driving belt,
• means on the apparatus supporting the belt for movement in a closed path extending lengthwise and along the oven means, and
• a variable speed drive means connected for operating the belt at a predetermined linear speed,
• said belt engaging each of the pulleys of the chucks and rotating them while at said speed in the range of 100-275 RPM during movement of the chucks by the conveyor and while the sleeves are undergoing said heating and shrinking in the oven means.

Apparatus for heat treatment of an article comprising

• an elongated oven for heating articles moved through it lengthwise,
• a conveyor mounted for movement the length of the oven, the conveyor including
• plural spaced chucks holding the articles in a vertical, upright position,
• the articles having shrinkable polyolefin plastic sleeves thereon extending telescopically over the exterior surface thereof, the oven heating the total surface area of the sleeve for shrinking the latter,
• a belt,
• a pulley on each of the chucks for rotating the latter about a vertical axis upon engagement with said belt.
• means supporting the belt lengthwise along the oven and engaging the pulleys of the chucks responsive to being conveyed along the oven,
• power means in running engagement with the belt for driving it in one direction at a predetermined velocity, thereby rotating the chucks and articles held thereby at RPM for producing a centrifugal force on the sleeves during movement of the latter through the oven sufficient for billowing them outwardly during the heat treatment of said sleeves and for heat shrinking them uniformly and in conforming relationship over the outer surface of the article.