How to Shrink Wrap a Machinery & Equipment?

Introduction

Industrial products such as machinery & equipment being stored or transported need protection but tarpaulins usually get shredded in the wind.

Industrial grade shrink wrap sheeting is also often used for creating very tight fitting transport covers which protect large products against weather damage during transport by road or during storage outdoors.

This guide is intended to be an overview of the industrial shrink wrap process. However, shrink wrapping requires the use of a hot air gun and often involves working at height. Before any shrink wrap job is attempted, ensure that you have received appropriate training that you adhere to your local health and safety regulations.

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Complete Encapsulation Method

This method is used when the object to be shrink wrapped can be rolled or lifted on top of a shrink wrap ‘base sheet’.

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Place base and cover sheets

1. Measure the item to be shrink wrapped and cut a shrink wrap base sheet approx. 50cm larger than the item on all sides. 2. Measure the height and width of the item to determine the roll width to be used.

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Preparation & covering

Pad sharp edges and protect any delicate items which might be damaged by shrink wrapping. If there are large ‘voids’ then it is best to install a ‘temporary support structure’ for the shrink wrap film using woven strapping every 2m.

For industrial shrink wrapping it is generally easiest to put the roll of shrink wrap on a roll stand at ground level so that it can be unwound easily. Using a stand also keeps the shrink wrap film off the ground and so keeps it clean and free from damage from stones which may cause small holes in the shrink wrap. Small holes are not a huge problem, but they will tend to enlarge as the cover is heat shrunk drum tight and will need repairing with patch tape afterwards.

Remember to position the film on the stand so that as you unroll it, the folds of the film are facing upwards. This will help to stop it snagging when you unfold it.

When shrink wrapping large products outdoors we always tape over the folds on the very end of the shrink wrap. This means that the shrink wrap can be pulled over the object as a narrow strip, and stops the wind catching the folds.

Once pulled over the object, the film can then be cut from the roll and unfolded.

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Welding/battening & Shrinking

Depending on the securing method used (see ‘planning’ above) the shrink wrap film is then battened, welded around the perimeter band or welded to the shrink wrap footprint that has already been placed underneath.

Although the heat shrink process will remove wrinkles and creases, you should always try and pull the film as tight as possible during the fixing and welding stage.

Finally, you can now begin shrinking the cover to get that ‘signature’ drum tight finish you are looking for. Using a propane gas hot air gun, start at the bottom and shrink upwards, using a technique similar to spray painting as you heat the cover and chase any wrinkles and creases away from you. You should try and shrink the cover in a systematic way, completely shrinking one area before moving on. Going back over an area that has already been partly heat shrunk may eventually start to thin the shrink wrap film and eventually create a hole.

Always use the heat gun sparingly around any areas which have already been welded. Shrink wrap film, once welded / heat shrunk, will have a tendency to make a hole when you go back again to finally shrink the cover. Although these small holes can be fixed using shrink wrap repair tape, lots of repairs will affect the finished appearance of the job.

To get the best results you should try and heat shrink 100% of the surface are of the cover. However, depending on the shape of the product you are covering, heat shrinking the sides may pull the shrink wrap over the top of the object ‘drum tight’ without additional use of the heat gun.

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Fit air vents & zipped access doors

Fitting a zipped access door or hatch is not essential but can be useful for some applications. The most common type of door features a ‘U’ shaped heavy duty zipper which is sewn into a rectangle of polythene. When the shrink wrap sheeting has been fully installed and heat shrunk ‘drum tight’ the door is taped into the required position using shrink wrap tape. Finally, the door is unzipped and the shrink wrap cut away to create an opening.