A General Guide to the Industrial Shrink Wrapping Process

Each shrink wrap project begins with a stated purpose such as:

• - Covering for outdoor storage or general protection from the elements
• - Covering for protection during shipment
• - Covering to contain construction environments

The purpose will generally help to determine the general method of industrial shrink wrapping to be used, these are:

• - Cover – top and sides, bottom left exposed
• - Encapsulation – object covered on all sides, 360 degrees

The method of the shrink wrap application can be used to determine the total square footage of coverage required as well as useful dimensions to help determine the best size of shrink film to use. Many wide width and long length films offer the ability to be cover large objects by length or width giving the installation preferences or limitations on the project. Optimizing the shrink wrap dimensions can reduce waste and speed up the shrink wrapping process overall. Drawings and photos of the object to be wrapped are ideal to assist in determining the optimal film size and wrapping procedure. Here are a number of considerations to keep in mind when learning how to use shrink wrap.

 

Choosing the right wrap – Shrink film material should be chosen based on both the size of the object, how long it will be outdoors if at all, and conditions during the period of time that the material is expected to perform. For assistance in deciding on what size shrink wrap please visit this page.

 

Preliminary Concerns – Generally, the preparation stage of the shrink wrap project takes the most time and has the greatest impact on the outcome and performance of the application. This stage includes:

 

Padding or Softening – the process of placing a padding material on surfaces that are likely to puncture, chafe or abrade the outer layer of shrink wrap. In some cases shrink film can be used in single or multiple layers to achieve a padded effect; an entire sheet laid over the object prior to the final shrink film layer is referred to as a bomb-sheet.

 

Structure for Shaping – To provide a shrink cover with the ability to drain water or sustain wind load, structure, or backing created with strap, lumber, steel or other materials can be used. Shrink films tend to conform to the highest points of a given object and structure can be used to create the ideal final shape for the purpose of the project.

 

Pulling the Shrink Wrap – This can seem like a simple step however, once the wrap is off the roll, retrieving the wrap off of the object or turning it a different way can be tricky. Be ever aware of the wind in leading up to this step and certainly consider wind speed and direction when deciding which way to pull the shrink film onto your object, if at all. If time allows, sometimes coming back when the wind is less severe can be the best choice to complete your project in the most effective way. Most, if not all prep work including padding should be completed and strapping should be set up and in place prior to pulling the shrink film. The best way to predict a wind gust on a shrink wrapping project tends to be opening a box of shrink wrap.

 

Securing the shrink wrap to the object – Shrink wrap installers have the following options to secure shrink wrap to an object:

 

Strapping – woven or high tension strap is placed around the perimeter of the object where the shrink film can be folded around the strap and heat fused to itself creating a continuous loop for the strap to hold onto. The strap must be secured to the object under adequate tension to hold the wrap in place, for best results use a strap tensioning tool. In some longer term or specialty applications, strapping can be replaced with coated wire rope rigged with turnbuckles to provide tension and additional strength.

 

Heat Fusing– this method is used to secure two edges of film together by heating and pressing the film layers together using a safety glove or tool to achieve a welded seam. This method is commonly used for encapsulation and oftentimes together with the Strip Lumber method discussed below.

 

Strip Lumber – common lumber can be used to attach shrink film by wrapping strips of lumber into the edge of the film in a way so that the film is more than one and a half times around the lumber strip and then fastened to the object with a screw, nail or other adequate fastener.

 

Heat Application – An even application of heat, continuously applied in both vertical and horizontal directions produces the best result of a smooth finish on the shrunken film. Across large expanses of drooping film, it is sometimes best to heat the film in sections to allow for the best rise of the film to the highest points. Heat should never be applied continuously to one section of film as the material does burn and will catch on fire. Proper fire extinguishers and a vigilant watch must be kept during the heat application phase for best safety practices.

 

Final Details – The final step in the shrink wrapping process is the detail work. Great care should be taken to ensure that the shrink wrap project lasts and performs as expected.

 

Taping – all heat fused seams should be taped so that at least 1.5” of tape are stuck to each side of the fused seam, for longer periods of outdoor exposure, Preservation Tape is the best choice to stand up to the UV rays of the sun. Preservation Tape contains UV inhibitors in both the film as well as the adhesive which allows it to be removed from many surfaces with little to no adhesive residue left behind.

 

Ventilation – adequate ventilation will lessen the effects of condensation from the moisture in the air. We typically vent boats and other objects with one vent approximately every six to eight feet on all sides of an object both vertically and horizontally.

 

Reinforcements – certain areas of the final project can be reinforced to provide additional protection from the physical and environmental conditions that the cover will need to endure. Large flat areas can be reinforced with a tensioned strap that is taped to the cover giving rigidity to the area to help it better stand up to wind load. Corners or other areas of contact with the object, the frame or the load straps/chains should be reinforced with pressure sensitive tape, commonly referred to as shrink wrap tape or preservation tape.

 

Moisture Control – when the interior of the cover or container needs to be kept dry, a desiccant can be used to absorb the moisture. These products are very effective when properly applied and are sensitive to the amount of cubic feet as well as the duration or time period of the application.

 

Corrosion Control – when storing or shipping items which are sensitive to corrosion, a VCI or volatile corrosion inhibitor product can help to prevent corrosion on a variety of metals. These products emit particles into the container or covered space which prevent the corrosion process from beginning or to slow down any existing corrosion. Choosing a VCI product to use in an application depends on the type of metal, environmental conditions and the duration of protection required.

 

Mildew Control – Similar to corrosion control products, these control mildew in enclosed areas over extended periods of time. Popular in both marine applications and shipping of less sensitive items.

 

Zipper Access Doors– can be placed onto a finished shrink wrap project to allow for people or air to move freely into or out of the cover. Zipper doors also provide convenient access to lifting points, control boxes or other areas for inspection or usage.

 

Feel free to contact us by email or phone with any questions about how to shrink wrap or to discuss your project.