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The market for shrink and stretch films in North America is set to grow a lot, going from $4.95 billion in 2023 to $5.94 billion by 2028. These films are great for packaging because they keep things fresh by protecting them from air and moisture. So, it’s really important to do accelerated stress testing to ensure the packaging works well and keeps the product safe.

What is Accelerated Stress Testing?

Accelerated stress testing involves subjecting packaging materials, like stretch films, to extreme conditions that mimic the real-world challenges they’ll face during transportation. Think of it as a stress test for packaging, where we push materials to their limits to uncover any potential weaknesses or vulnerabilities.

stretch film testing

Testing stretch film helps companies understand its properties and protective abilities better. This helps them find problems in a controlled lab before using it for real distribution.

The merits of these tests encompass:

1. Ensuring Proper Application and Load Stability: By subjecting the stretch film to rigorous testing, companies can verify the accuracy of its application and ascertain load stability. This ensures that products remain intact and secure throughout the transportation journey.

2. Optimizing Baling Protocols: Testing stretch film helps figure out the best way to wrap products for shipping. This customized approach makes sure items are packed well, so they don’t get harmed while being moved around.

stretch film testing

3. Optimizing Film Usage: Testing helps find the right amount of stretch film for the best protection. This not only reduces waste but also has many good outcomes, like less pollution from transport and spending less on materials and shipping.

In simple terms, testing stretch film isn’t just about checking how strong it is. It’s like a smart tool that helps companies make better choices. This leads to safer products, smoother work, and a greener way of doing things.

Guide to accelerated stretch film stress testing: methods and regulations

In today’s packaging world, making sure stretch films work well needs a planned testing process. Different groups have made tests to check if stretch films protect loads. In this guide, we’ll look at the important rules and ways to do proper stretch film testing.

Characterizing critical properties of stretch film

ASTM D-5458: Peel Cling of Stretch Wrap Film
The ASTM D-5458 test is a precise way to measure how well layers of stretch film adhere to each other. This evaluation is crucial for determining how well the inner and outer layers stick together. By ensuring the correct placement of the film in baling machines, complications like the film clinging to pallets during shipping can be avoided.

ASTM D-5748: Protrusion Puncture Resistance of Stretch Wrap Film
The ASTM D-5748 test helps assess the ability of stretch film to withstand punctures, especially when wrapping products with sharp edges. This examination helps determine if the film is effective in protecting items that are vulnerable to getting holes.

ASTM D-882: Tensile Properties
The ASTM D-882 test focuses on understanding the breaking point and maximum stretching capacity of stretch film. These insights are crucial for understanding the overall durability of the film and its ability to handle mechanical stress during transportation.

Ultimate Stretch before Break
Conducted while the film is still in its rolled-up state, the Ultimate Stretch before Break test helps manufacturers comprehend how much the film can be stretched before breaking when used in baling machines. This information is essential for determining the optimal stretching level needed to maintain load stability.

ASTM D-1922: Propagation Tear Resistance
The ASTM D-1922 test is a critical way to measure the tear resistance of the film. Given the susceptibility of film roll edges to damage during storage and transportation, assessing tear resistance is of utmost importance. Improved tear resistance directly correlates with smoother baling processes and increased load stability.

Rigorous testing protocols for correct stretch film application on the entirety of the load unit:

Stretch Film Containment Force: This assessment involves determining the force exerted by the stretch film on the packaged products or items. Ideally, the containment force should match the maximum capacity of the products without causing deformation after the film is applied. However, this factor alone does not ensure load stability.
Post-Wrapping Film Thickness: Measuring the thickness of the film layer after the baling process provides insights into whether the film has been pre-stretched to the optimal usage range. For instance, if a 23-micron film is utilized, and the measured thickness of a film layer on the pallet is only 16 microns, it indicates inadequate pre-stretching and jeopardizes load stability. Conversely, a measured thickness of 9 or 10 microns after baling indicates proper pre-stretching. Nevertheless, this measurement alone doesn’t guarantee load stability.
Total Film Weight after Wrapping: Calculating the total weight of the film in use, considering its density, the number of rotations, the baled load’s perimeter, and the film’s thickness post-baling, can yield an approximate total stretch percentage. This encompasses both the pre-stretch due to the pre-stretch carriage and the post-stretch caused by the force between the roll and the load where the film is applied. If the calculated total stretch percentage closely aligns with the pre-stretch percentage specified during the Ultimate Stretch Before Break test by the manufacturer, it indicates the film has been optimally stretched. However, this parameter alone doesn’t guarantee load stability either.

Accelerated stress testing and Validating Load Stability

Apart from looking at individual properties, making sure loads stay stable needs a thorough approach that checks more than just the film. Things like how the pallets are arranged, the quality of packaging, and how the film is spread out all matter.

For instance, getting the film on right involves things like how it’s wrapped at the edges of the pallets, how layers overlap, how it’s wrapped higher up, and where the film is placed in areas with different grips.

The real confirmation that the film is put on correctly comes from the rigidity or stability test. In this test, the team puts a load on a flat surface and slowly speeds it up until it stays steady for a certain time. If the load doesn’t change too much, it’s considered stable under that speed. This shows that the film is put on well to handle side forces like the ones during transport.

Accelerated stress testing: testing equipment

Equipment for testing stretch film includes two distinct types of machines, each engineered to assess load stability or rigidity by replicating the horizontal accelerations and decelerations encountered during road transport.

Horizontal Stability Tester

Boomerang Horizontal Stability Tester

One of these machines is the InnSlide Horizontal stability tester, which is accessible within specific package and packaging testing laboratories, as well as select stretch film manufacturers and prominent corporations.

Another option is our innslide Boomerang a Compact in dimensions solution, a patented solution from Safe Load Testing Technologies that is intentionally engineered to be owned and utilized by any company within their premises.

With a history spanning two decades in the field of transport simulation, Safe Load Testing Technologies has been instrumental in assisting companies in selecting appropriate equipment to enhance their packaging solutions, encompassing stretch film testing. Get in touch with us, and we’ll elaborate on how our expertise can benefit your company.

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