Reprinted with permission from MLS Machinery, Inc.
Packaging equipment covers a fair amount of different kinds of machinery, the most common that we will deal with is probably the Shrink Wrapper. Shrink wrapping is when a package is wrapped in plastic and put through a heat tunnel, where it is forced to shrink by means of heat. The plastic used is called polyethylene which is the most commonly used plastic for shrinking because it shrinks the quickest and easiest, and is very strong. Shrink tunnels basically come in many sizes, some are used for knock down (unassembled) furniture, which the customer puts together themselves, in which case the package is relatively small and the tunnel can be 18-24" wide by 6' long by 6-18" high.
In the kitchen or upholstery industry when a complete couch or cabinet is shrunk, the tunnel has to be much larger, being anywhere say from 48" wide to 12' long. Most shrink tunnels have a conveyor system that feeds through the tunnel, as well as a heating system that can be adjusted for the various sizes of package. There are also blowing fans to cool the packages when they come out of the tunnel, therefore speeding up the shrinking process. There are different ways of wrapping the polyethylene on the package before it goes into the shrink tunnel. It can be done by an automatic system where it pre-cuts the polyethylene, wraps it around the package and then cuts the plastic on the end which then prepares the polyethylene for the next package coming into the machine, or, an L-sealer or L-bar can be used which makes an L-shape on the polyethylene once it is wrapped around the package. This L-shape is created by heat which in fact seals the polyethylene together.
Other packaging equipment consists of pallet wrappers or packaging strappers which strap the flaps of a carton together so closing a box or the larger units will strap a number of boxes that have been pre-closed and have been put onto a pallet or skid together so they do not move during shipping. In both cases the package will pass under a bridge of the strapping machine that contains the nylon strapping, which is in roll form and as it passes, the strapping is automatically released, tightened and heat sealed together.
One other type of packaging equipment that is used in our industry is a polyethylene wrapper that is used to strap a number of long moulded parts together, as seen in a hardware type store. Here, a number of pieces of moulding come together and again pass through a tunnel. The mechanism that contains thin plastic wrapping almost like saran wrap rotates around the moulding in the tunnel as the moulding automatically feeds through the machine which is called an Orbital wrapper. This can also be used for cabinets and the raw material is cheaper than polyethylene.
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