Page 24 - The Inside Scoop Archive

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To: Inside Scoop Reader

How to Determine Pre-Stretch On Load For Any Machine!

We know how important it is to make sure that the marriage between your value added stretch film and your stretch
machine is producing the kind of performance and film economy that you are paying for, but how can you really know
without spending an arm and a leg to find out? Buying a Highlight Industries film test kit is a good place to start, but
how do you go about holding a 10" wheel ( to measure prestretch on the load ) next to a roll of film traveling around the
pallet on a rotary tower arm, or an octopus ring, or even on a battery powered robot stretch machine like the Wulftec
Robot on our website? The answer is that you can't, there has to be another way. There are several calculators that
have been designed to help you get the answer, and they work on any type of machine being wrapped with stretch film.
The one that I most often use for getting the percentage of pre-stretch on the load is one designed in excel by Carla
Kastl of Pliant Corp.

The Pre-Stretch Calculator on the left is a working model. Just click on the
Calculator to bring it up on your web browser. You may enter any numbers
you wish to replace the black numbers and the red answers are automatically
calculated. You may then save it to your computer for future use. If
clicking on the Calculator does not result in a pop up in your browser, you
may download the Calculator by going to the Inside Scoop Filing Cabinet as
indicated below.

The Calculator is a perfect answer to determining pre-stretch on load when
you cannot use a 10" wheel to put ink marks on the film as it is being applied
to the pallet.

Note that all you have to do is: (1) measure the pallet width and length. It is
not necessary to measure the height; (2) know the gauge, width, and footage
of the stretch film you are using; (3) count the number of total rotations
around the pallet as it is being wrapped; and ( 4 ) cut off the film from the
wrapped pallet and weigh it. Input this information into the indicated part
of the calculator and behold your pre-stretch percentage on the load.

It is important to know the percentage of prestretch on the load for a number of reasons. If you are using a film that
is capable of being stretched 250% or more on your machine, but you are only getting 175% stretch on load then you
need to look at upgrading your pre-stretch rollers to a higher percentage, and ensure that the rollers are in good
condition in order to improve your performance. This upgrade can be as little as spending a $ 100.00, and can
potentially save you hundreds or even thousands of dollars per year based on the number of pallets you wrap. Another
reason is that many of the better stretch films actually hold your pallet tigher when they are stretched further. If
you do not stretch them at a high enough percentage, they cannot perform at the levels for which they were designed.

I would like to challenge you to use the calculator above to check your pre-stretch percentage on load and email the
results back to me. If we get enough feedback, we will review them in a future issue of the scoop. No names will be
used.

file://C:\Documents and Settings\William Jackson\Local Settings\Temp\tmpA7.htm 10/21/2006