Temperature matters
Stretch film lasts for a long time, but extreme temperatures can impact performance:- Heat: High heat affects film by making it more extensible so that the wrap no longer maintains its width and will stretch more than desired.
- Cold: The opposite is true with freezing temperatures. Cold exposure results in film that no longer stretches as expected, reducing the yield and tackifier.
Also read: Outdoor Protection and Advertising with Pallet Stretch Wrap
Moisture damage
Temperature is not the only factor in stretch film expiration. Humidity also impacts film due to its cardboard core. The higher the humidity, the greater the likelihood of the core squeezing or crushing. The result can be a complete product failure or an inability for the core to fit onto a wrapping machine. To combat this, manufacturers and distributors wrap products more slowly during times of high humidity to avoid core crushing. Another side effect of humidity occurs when the product itself is the source of the humidity and higher temperature. Most stretch films act as insulators, meaning when products are wrapped, there is nowhere for air to go. This is a good thing for most products as it reduces exposure to oxygen. However, wrapping a product when it is still warm (such as eggs) may lead to condensation. Vented film allows air to pass through the film, creating a pathway for moisture to escape that would otherwise be trapped and damage the box or any tape adhesive.Lifespan and appearance
Film has a long shelf life, but some factors affect the lifespan and appearance inherent to the film itself. For instance, pre-stretched film can have a shorter lifespan due to its manufacturing method. Air entrapped in the process of the film being stretched is eliminated over time as its core collapses, making the roll tighter and reducing the pre-stretched film’s effectiveness. White film oxidizes, which doesn’t affect performance but creates discoloration; sometimes, the ends of the rolls will turn pink. The appearance of stretch film directly relates to branding and first impressions of product quality.‘First in, first out’ addresses stretch film expiration
As temperatures and other conditions often change throughout the year, predicting which film is best for all-around performance becomes difficult. The best way for warehouse operators and distributors to manage stretch film expiration is instead to employ the “First In, First Out” (FIFO) aging concept for rotating stock. FIFO ensures inventory is used in order of age, ensuring wrap is not stored any longer than ideally a year. A few more storage tips that reduce the risk of stretch film expiration include:- Covering stock: Dust affects the perception of the wrap and may make it seem aged. Covering stock prevents this dust from building up during storage.
- Reduce water exposure: As wrap has cardboard cores, water exposure is critical to extending the lifespan of stock, even if the wrap itself isn’t affected.
- Ultraviolet Inhibitor (UVI): Remember that UVI wrap only lasts six to 12 months after exposure to ultraviolet light, meaning the lifespan of products stored outdoors may be less than expected.
- Treated film: When wrap is treated, a rough spot is applied for ink to adhere to. When the wrap sits for a long time, that treatment will degrade, leading to issues with sealing products as time goes on.
Also read: Printed Stretch Film: 5 Questions You Should Ask