There has some kinds heat shrink machine will realize L bar sealer shrink wrapping machine,such as L-semi automatic heat shrink film packing machine, side sealing shrink wrapping machine, full-auto L bar sealer with tunnel will realize over wrapping. Overwrapping Achieves a total enclosure of the product by a perimeter sealing process performed on L-bar type machines that utilize Centre folded film. Total enclosure can also be achieved using flat sheet film on a Flow wrapping machines.

Overwrapping is best suited for low height, rectangular shaped products such as stationery, magazines, video tape, CD's etc. Although the writer has in the past designed L-Bar type machines 2.4m long x 1.2m wide with a suitable 1.35m wide Shrink Tunnel.

When performed on an L-bar sealing machine the operation is as follows The end of the film is sealed across the width and forms one of the sealed sides of the pack. Product is inserted between the layers of film, then transferred together to the sealing station. Here the remaining two sides are sealed and product is now completely enclosed by the film.

From there the package is moved onto the shrink tunnel conveyor to complete the operation. Simple L-Bar machines are manually operated although automatic models are also available.

There are also "All in one" L=Bar type of heat shrink machine units where the Sealing and shrinking are performed in one operation. The Sealing station consist of a hood, where the product is enclosed in film. Once the seal is complete, Hot air is blown around the pack to shrink the package. These machines are best suited successful in low speed, office or dispatch applications.