The Two Calculations of Pre-stretch logo

The Two Calculations of Pre-stretch

  • Published: July 23, 2020

  • Updated: July 29, 2020

Is 300% pre-stretch better than 240% pre-stretch? Not always...

Pre-stretch can be confusing to compare between machines as manufacturers don't calculate pre-stretch the same way as other manufacturers. Not knowing the difference could lead you to choosing a machine that isn't as efficient or cost effective as you initial thought.

Method 1 - Overall length

The first method bases the percentage on the film's stretched length in comparison to the original length. For example, if Machine A takes 1000mm of film and converts it to a total 3000mm of film, these manufacturers call this 300% Pre-stretch.

Method 2 - Additional Length

The second method bases the percentage on the additional length gained from stretching in comparison to the original length. If Machine B takes 1000mm of film and converts it to a total 3000mm of film, this is 2000mm longer than the original 1000mm width. So these manufacturers call this 200% pre-stretch as it adds 200% to the original length.

In these two examples, both Machine A and Machine B stretched the wrap the same amount, but because of how each manufacturer defines pre-stretch differently, how they display the pre-stretch percentages make Machine B appear to stretch less than Machine A.

Our machine pre-stretch is defined by the additional length gained in method two. Our standard 240% pre-stretch head increases the length of your film an additional 240%. Pre-stretch heads can provide from 30% - 400% pre-stretch. It's essential to know how the manufacturer measures their pre-stretch percentage when comparing different models of pallet wrappers.

 


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