Premiering our new C&D Shrink Bundling Video!
Two roll bundling machines require two rolls of poly (most commonly one roll stationed above a conveyor and the other below). The two rolls are welded together to create a seal. This seal is located between two conveyors, once the product passes from one conveyor to the next it pushes through the sealed films, wraps the product, seals and cuts. The wrapped product is now ready to enter the shrink tunnel. These convection style ovens with temperatures ranging between 3-400 degrees heat the film quickly to begin the shrink process. Polyethylene films are designed to shrink outside the oven / tunnel so, as it cools, the film will conform around the product creating a tight, wrinkle free package, with small bulls-eyes (holes on either side of the package that are not sealed ie. “handles” on cases of water). Once fully cooled the package is ready for further packaging / palletizing.
Gauges of shrink bundling film vary between 1-4 mil. Determined by the overall weight of the product that is being packaged and whether it is supported or not (tray or no tray). The 100% virgin resins used in the bundling film formulation assure the end user no slip performance for the end product. No slip is very important when stacking / palletizing items like cases of water. 100% virgin resin is also critical in seal strength and consistency. Maintaining the same resin formulation throughout a specific production, and from order to order reduces the chance that seal bars on the bundling machines will be “gummed up” foreign resins and creating gaps in the seal.
One roll bundling film also known as “cut and wrap” is designed for high speed bundle applications. This film is formulated specifically to work with a “flying knife” the cuts a specific length of film that loops over the product prior to going through the heat tunnel. Due to the high rate in which the film is being applied special additives are included in the film to avoid the potential of static electricity build up.
Centerfold shrink bundling films are designed for fully enclosed applications. These films are used on machines such as an L-Bar sealer. Products on a conveyor push through L-bar sealer unit it creates a fully encapsulated sealed bag prior to moving through a shrink tunnel. As mentioned above, polyethylene shrinks as it cools, so all CF shrink bundling film must either be manufactured with venting or the equipment must have a venting mechanism the vents in-line. The heated trapped air must escape for the film to shrink properly.
Crayex’s long history and proven success in the shrink world, including bundling film, is from our understanding applications, equipment, customer, and market demands. Some may think of bundling film as a “commodity” but, at Crayex every application and customer is unique and we formulate products to meet and exceed their specific needs.
Please Visit our C&D Bundling & Wrapping Film Product Page for more information, or request a quote with our handy quote form!