L-Bar Sealers: An Inexpensive Way to Wrap Packages
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Sometimes you want a good looking six-sided wrap but don't want to spend a lot of money. An L-Bar sealer may be the solution for you.
L-Bar sealers can be completely manual to fully automatic, with varying degrees of automation in between, depending on budget and production requirements.
Other shrink wrappers use a single layer flat film. L-Bar sealers use a film folded lengthwise on the centerline to form two layers. As the film is unwound from the roll, guides open the two layers. One layer goes under the product loading table or conveyor. The top layer is held up by a guide to allow the product to be placed in the pocket formed by the fold and the cross seal.
Film and product are moved forward into the sealing area until the product clears the cross seal bar. The two heat sealing and cutoff bars, arranged in an L, are pulled down. The cross seal seals the trailing edge of the film, the leading edge for the next package, and cuts the seal in apart. The side bar seals longitudinally and cuts off any excess film.
The package passes to a heat tunnel where the film shrinks to make a tight, six-sided, wrap. It is important to allow a means for trapped air to escape. Otherwise, the package will look like a pillow. One method passes the film over a roller with pins to make a series of pinholes. Pre-perforated films are also available.
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An advantage of the L-Bar sealer is that a single width of film can be used across a range of package sizes. When a wide film is used for a small product, it will generate excessive waste from the side trim. Eliminating the need for multiple roll sizes and changeover often overrides the cost of this waste.