Updated October 2026. Originally published July 2016.
A hot facility in July is uncomfortable for your crew. It is also quietly working against your packaging materials. Shrink film, stretch film, and plastic strapping are all thermoplastic products, and sustained heat changes their physical properties in ways you may not catch until a roll jams a machine, a load shifts in transit, or a strap fails to hold tension. The fixes are not complicated, but they require some deliberate habits around storage, scheduling, and inspection.
Store shrink film in the coolest part of the warehouse, away from sunlight and dock doors, within a target range of 30 to 77 degrees Fahrenheit.
The coolest spots in most facilities are closest to the floor, on the lowest levels of your pallet racks. Heat rises, so the higher the rack position, the warmer the ambient temperature. Keep rolls away from windows, skylights, and any door that opens to the outside repeatedly during the day. Dock doors and high-traffic entry points are particularly problematic because temperatures there fluctuate dramatically as trucks come and go.
Schedule film deliveries early in the day before peak heat. Film that rides in a dark trailer during afternoon hours in July can arrive warm enough to cause problems before it ever reaches your line. Giving rolls time to equilibrate in a cooler storage area before use is worthwhile. If delivery timing is outside your control, make sure the material is moved off the dock quickly rather than staged in a hot receiving area.
Two warning signs you can spot before putting a roll on the machine:
PVC is more sensitive to temperature swings than polyolefin. PVC becomes brittle when stored too cold and wrinkles and sticks when stored too warm. If you are overcorrecting for summer heat by moving rolls into a freezer or refrigerated area, stop. PVC that has been exposed to extreme cold can become brittle enough to shatter if dropped, which introduces a safety hazard on the floor. The goal is cool and stable, not cold.
For operations that package frozen foods or refrigerated products, where film will be exposed to cold by design, a quality polyolefin shrink film is a better fit. Polyolefin is durable, less affected by temperature changes, and FDA-approved for food contact. It has replaced PVC in a wide range of applications for exactly these reasons. For a broader look at how the two compare, the complete guide to shrink film covers material selection in detail.
If you run both PVC and polyolefin and want to confirm your heat tunnel settings are dialed in for summer conditions, the appropriate tunnel temperature range for each film type differs. A separate post on temperature restrictions on shrink film covers those settings directly.
Stretch film that is stored or applied in high heat can lose its holding tension, leaving a pallet that looked well-wrapped in the morning significantly less stable by the time it is loaded into a hot trailer.
Stretch film works by applying and maintaining tension across the load. The elastic memory of the film is what pulls product tightly together and keeps a pallet stable in transit. When ambient temperatures climb, the polymer chains that create that elastic memory slide past each other more easily. The film relaxes, permanently deforms, and stops pulling. The load does not fail dramatically; it just quietly becomes less contained.
The staging and loading sequence matters here. Film applied correctly in a 68-degree morning warehouse can lose meaningful tension by the time that same pallet has sat on a hot dock, been loaded into a trailer that has been baking in the sun, and traveled for an hour or two. If you are seeing shifted loads, falling product, or freight claims during summer months that you cannot explain by machine settings alone, heat-related film relaxation is worth examining.
On the storage side, the same principles that apply to shrink film apply to stretch: keep rolls away from direct sunlight, off the top rack levels, and away from dock and exterior doors. Film stored in good condition going onto the machine gives you the best chance of maintaining containment through the distribution cycle. For a broader look at how stretch film behaves and what affects its performance, the complete guide to stretch film is a useful reference.
Cling is another area to watch. Stretch film rolls stored at high temperatures can experience cling migration, where the cling additive moves toward the film surface faster than normal. In practice, this means layers of film on the roll fuse together, and when the roll is run on the machine, the film tears out at the fused point rather than unwinding cleanly. If your operators are seeing more film breaks than usual during summer months, check whether rolls have been stored in a warm area before use.
The shelf life of stretch and shrink films is another consideration worth reviewing if materials sit in inventory through multiple summer seasons.
Polypropylene strapping is particularly vulnerable to summer heat; extended exposure in hot trailers or staging areas can cause the outer layers of a coil to shrink and the applied tension on a strapped load to drop faster than it would in cooler conditions.
This is easy to overlook because strapping does not show heat damage the way film does. There are no sticky rolls or visible sag to catch during inspection. The coil looks fine. The tension loss happens after the strap has been applied, especially if the load sits in a hot staging area or inside a sun-exposed trailer before or during transit.
A few practical adjustments for summer:
A consistent summer storage routine reduces the chance that heat damage reaches your line undetected.
For more detail on storage practices and how environmental conditions affect film shelf life, the posts on best practices for storing shrink film and on film expiration and shelf life go deeper on both topics.
Industrial Packaging, founded in 1953 and based in Webster, Massachusetts, supplies shrink film, stretch film, and strapping alongside the machinery and technical service that support them. If heat-related performance issues have you looking at a different film type or strapping material, call (800) 233-5288 or visit the contact page to start the conversation.
More questions plant and purchasing teams ask on this topic.
Manufacturing date matters less than storage conditions after the roll arrives at your facility. What degrades film fastest is cumulative exposure to heat over time, so a roll that has sat near a dock door or on an upper rack through a long hot stretch will be more compromised than a freshly delivered roll stored properly, regardless of when it was made. Rotating inventory on a first-in, first-out basis and maintaining consistent storage conditions is more protective than tracking manufacture dates.
Start by checking the roll before the machine. If the film surface is tacky, layers are fused, or the roll profile is uneven, the material itself is the problem. If a fresh roll from a cooler storage location runs cleanly on the same machine with no adjustments, heat damage to the previous roll is the most likely cause. If jams continue with a fresh roll in good condition, then machine settings, film path alignment, or blade wear are better places to look.
Both are thermoplastic films and both are affected by sustained high temperatures in storage, but their different manufacturing processes give them different cling and elastic memory characteristics that can interact with heat somewhat differently. Cast film typically has more consistent cling and clarity, while blown film tends to have higher puncture resistance. For summer storage, the practical priority for either type is the same: keep rolls cool, inspect before use, and do not run film that shows signs of heat exposure.
If you want to talk through your packaging, your packaging equipment, or how you buy, start a conversation with Industrial Packaging.