Common Shrink Wrap Questions

What is shrink wrap?

Shrink wrap is a generic term that can refer to many materials. Stretch film used to wrap pallets of goods is often referred to as shrink wrap. Heat shrink wrap is a different material that shrinks when heated and is commonly used to protect commercial, retail and personal products. Both are essential to prevent damage or loss of products.

Can you make your own shrink wrap?

Yes, heat shrink wrap can be made yourself from everyday household items, but the finished product does not look professional. pvc shrink wrap bags and a hair dryer will shrink the product. The tape before heating helps to fix the shrink wrap together. The finished look will not be as clean as a sealer, but the packaging should stay on the product. We recommend purchasing a sealer, heat gun and shrink bags to wrap small amounts of product.

What is the difference between plastic packaging and shrink wrapping?

Plastic wrap and shrink wrap are ambiguous terms that refer to many different materials. Cling wrap can be materials such as kitchen wrap, stretch film, cellophane, etc. Shrink wrap can also be several of these materials. Heat shrink packaging differs from all materials due to the additives used in the extrusion process. These additives allow the compounds of the material to shrink when heated without melting the plastic.

Is shrink wrap the same as cling wrap?

Although both can be made from similar compounds, shrink wrap contains additives specifically designed to shrink when heated. PVC was once the material of choice for cling film and shrink wrap. In recent years, polyolefin has become the material of choice for shrink wrap. Do not heat on cling film; it will melt.

How do I measure shrink film?

Measuring shrink film is relatively simple, but depends on the type of shrink product you intend to use. See below for the measurement formulae for each type of film. Remember, if the exact size required is not available, choose a size larger. All our shrink films have a minimum shrinkage of 30%.

Folded shrink film measurement formula

Width + Depth x 2 x 1.1 ÷ 2 = required centrefold film width.

Shrink bag measurement formula

Same formula as above to determine bag width, for length, add 1-2 inches to allow room for sealing.

Shrink tube measurement formula

For square objects, use the same formula as above, but most people use tubing for cylindrical purposes. If measuring round objects, use the following equation.

Circumference x 2 x 1.1 ÷ 2 = required tube width.

When to use shrink film and when to use stretch wrap?

Shrink film is often used to protect and package individual products such as toys or CDs. it is also used to help bind multiple products together. It is used to bundle sodas, water bottles and various other packaged products together. Often, stretch wrapping is used to secure boxes and products to pallets for transport. It can also be used to secure other objects together for transport or storage. A variety of special films can be used for stretch wrapping. Examples include UV stretch film, ventilated pallet film, anti-static stretch film, coloured stretch film, pre-stretched stretch film, etc. Are shrink and stretch films recyclable? Both shrink wrap and stretch film are recyclable. Please check with your local recycling centre to ensure they accept flexible plastics.

If you are interested in types of shrink film or want to learn more about its specifications, material, and prices, please email us directly at info@hyfpack.com. We are more than happy to answer your questions.

However, shrink wrap packaging can present certain challenges that can undermine its effectiveness, especially if not applied correctly. These issues include unsightly wrinkles, burn holes, poor seals, and product damage.

1. Wrinkles and Creases in Shrink Wrap

What is it? Wrinkles and creases appear when the shrink film is not applied uniformly or when the film is excessively large for the item being wrapped. This results in folds and bunching of the film, which can make the packaging look unprofessional and may reduce the protective qualities of the wrap.

Causes:

Incorrect film size (too much or too little material).

Improper heat distribution during the shrinking process.

Machine settings that are not optimized for the product size or material type.

Solution:

Choose the Correct Shrink Film Size: The film should fit snugly around the product with minimal excess. It should not be too large, as this can cause bunching or wrinkling.

Adjust Heat Settings: Ensure that the heat applied during the shrinking process is uniform across the entire package. This can be done by adjusting the shrink tunnel temperature and speed settings.

Perform Test Runs: Before packaging in bulk, test the settings to ensure the film shrinks evenly and does not create wrinkles.

2. Burn Holes in the Shrink Film

What is it? Burn holes in shrink wrap occur when the material is exposed to excessive heat, causing the film to melt or burn. This creates holes that compromise the protective properties of the wrap and may expose the product to damage during transportation.

Causes:

Overheating during the shrink process.

Poor control over the heat distribution in the sealing or shrinking area.

Solution:

Reduce Heat Settings: Lowering the temperature settings on the shrink tunnel or heat sealer can prevent the material from burning.

Use Vent Hole Film: This type of shrink film is designed to allow air to escape as the film shrinks, reducing the risk of burn holes.

Regular Equipment Maintenance: Inspect your heat sealing elements to ensure they are functioning correctly and consistently.

3. Ballooning

What is it? Ballooning refers to the formation of air pockets within the shrink film after it has been applied, leading to an inflated, balloon-like appearance. This typically occurs when the film is sealed before it begins to shrink, trapping air inside.

Causes:

Insufficient ventilation in the shrink film.

Sealing the film too early in the packaging process before it has begun to shrink properly.

Solution:

Apply Ventilation Holes: Ensure the shrink wrap has ventilation holes to allow air to escape during the shrinking process.

Control Conveyor Speed: Slowing down the conveyor speed gives the air more time to escape before the film is sealed.

4. Weak or Improper Seals

What is it? A weak or poorly executed seal can result in the shrink film not adhering properly to the product, which may leave the item exposed to the environment and vulnerable to damage.

Causes:

Insufficient pressure from the sealing bar.

Incorrect temperature or time settings for sealing.

Using low-quality shrink film.

Solution:

Increase Film Thickness: Using a thicker shrink film may provide a stronger seal, especially for heavier or more delicate items.

Check Sealing Settings: Ensure that the sealing bar is set to the correct temperature and that enough pressure is applied to create a secure seal. Regular maintenance of sealing equipment is crucial to avoid malfunctions.

5. Uneven Shrinkage

What is it? Uneven shrinkage occurs when the shrink film shrinks more in some areas than others, resulting in an uneven appearance. This issue can be visually unappealing and might compromise the protective functionality of the packaging.

Causes:

Inconsistent heat distribution during the shrink process.

Incorrectly sized shrink film.

Uneven application of the heat source.

Solution:

Adjust Heat Distribution: Ensure that the heat source is evenly distributed around the product. This can be done by adjusting the position of the heat elements or the shrink tunnel settings.

Optimize Conveyor Speed: Slowing down the conveyor belt gives the film more time to shrink evenly around the product.