Containment is Crucial
Containment is the ultimate goal of stretch film. Get the load from point A to point B in tact with no damage to product. Knowing the amount of containment it takes for your specific product and knowing how to measure it allows you to choose a film that meets that requirement at the lowest cost. In the industry, we measure the amount of force the film applies to the product. This measurement can be done with several different methods or tools, you simply must be consistent in your measuring techniques.
For many years, force was measured at the top of the pallet only. In theory, the load was unstable at the top so they needed to measure the force at the top. Consider this, if you are painting a room in your house, would you apply two coats of paint on the "cut in" section or trim and then only one coat of paint it's the roller in the middle of the wall? The answer is simply no. You want the wall to be painted evenly. This is true with stretch film. You want even force to load at the top of your pallet, the middle of your pallet, and the bottom of your pallet to ensure it is secure for transit.
Pre Stretch Gear Ratio
Pre stretch gears are a mechanical setting on most machines (some machines allow for a digital setting) It is a fixed ratio tied to the drive rollers through a belt or chain. The only way to change the pre stretch settings on this type of machine is to physically change out parts. Understanding your pre stretch gear ratio gives you an idea of how your equipment is intended to perform.
On Pallet Stretch
On pallet stretch is a mathematical calculation that tells you how far your film is actually stretching. This number is almost always different than your machine's pre stretch settings. On pallet stretch identifies the machine performance combined with the film's performance.
Blog Author: Carla Kastl
Carla Kastl is a 14 year industry veteran and the knowledge and talents she brings to Paragon are one of a kind. Carla’s wealth of knowledge makes her a perfect “teacher” about film products and her primary goal is always to educate the customer first. She also is constantly pushing herself to learn more about her industry, and wants to know the more about “film and equipment than anyone else.” Carla even loves public speaking and looks at it as a great opportunity to teach a lot of people at once.