How To Buy Used Shrink Wrapping Machinery
Inspecting the Shrink Tunnel and Conveyors.

Next take a look at the heat shrink tunnel. Turn it on and make sure that all the systems are functioning properly.

• Listen to see if the rollers are squeaking.
• Look inside to see the general condition of the hot air chamber.
• Feel to see if there is a lot of motor vibration coming from the fan motor.
• Chains rubbing
• Check to see if the conveyor are tracking properly and are not rubbing.
• Look for moving parts wearing or scraping each other.
• Check for good air circulation and that the air paths are not restricted.
• Check to see that the tunnel temperature is rising at a steady pace.
• Check to see that the temperature in the heat shrinking tunnel is not fluctuating.
• Check to see that the temperature is maintaining at the temperature set point.
• Inspect the tunnel curtains for wear.
• Inspect the control box to see the condition of the controls and wiring.
• Inspect the conveyor drive system, chains, sprocket, belts, pulleys, motor, ect..
• Inspect the conveyor belt for wear and tear.

So if after testing your product and shrink film on the shrink packaging machine that you are considering purchasing and the product and the film work on the shrink packaging machine the next thing is too see what type of shrink are you getting on your product. Having a good heat shrink tunnel is as important as the sealer. The heat shrink tunnel is what shrinks all the excess film off to create the best looking packaged product. Make sure that the tunnel has good air velocity. It is important to have good air circulation in the heat shrink tunnel. It is also important that the temperature in the heat shrink tunnel does not vary more than 5 degrees + or – the set point. The conveying system is also very important. Having the right type of conveyor belt for the type of product that will be carried through the heat shrink tunnel is imperative. Some types of conveyor belts will leave belt marks on the finished product depending on the size and weight of the product.

There are many types of conveyor types like:

• Solid flat silicon conveyor belt
• Solid flat Teflon conveyor belt
• Teflon mesh conveyor belts
• Stainless steel mesh conveyor belts
• Stainless steel wire conveyor belts
• Plastic link conveyor belts
• Roller bar conveyor belts

There are pro’s and con’s about what the different conveyor will do for you. Let say you have a Teflon mesh belt you will get great air circulation but sometimes will leave belt marks on the product if the heat shrink tunnel is run to hot. Maybe the heat shrink tunnel that you are looking at has a solid Teflon conveyor belt. Then you will not get good circulation to the bottom of the product that is lying on the conveyor belt. Some belts like this are heated to compensate for this problem. The best way to tell is to try running your product in a shrink film containment through the heat shrink tunnel and see what the results are. Sometimes the air velocity, temperature and the conveyor speed can be adjusted to help get a good looking shrink package.

The way that the shrink film is placed around the product is very important. The shrink film should be some what even all around the product. Keeping the shrink bag as small as possible is usually the best way to keep the shrink containment looking good. A good heat evacuation system can also be important in making sure that the shrink film balloon is shrinking properly.

Make sure that the tunnel is fast enough to keep up with production speed of the sealing machine. Not that the conveyor is fast enough but that the tunnel can run at the speed of the production that will be coming off the sealer and still come out with a good shrink packaging appearance.

A good thing to also look at is the product transfer. It is very important that the product transfer properly between the used shrink packaging machine and the heat shrink tunnel. The sealer should only be slightly above the height of the heat shrink tunnel conveyor.

After going through all this then you should ready to buy your used shrink packaging machines. If you have any further question on any of this please feel free to CONTACT US

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