Easy Way To Test Stretch Film Stretch Rate
Stretch film is made to do exactly what the name implies, stretch. By stretching a stretch film to the maximum stretch rate, companies save money on film costs and reduce product loss. Hand and machine stretch film commonly offer different stretch rates. Different brands and resin formulas also offer different stretch rates. With the simple steps below, companies can find out the amount of stretch being reached by hand or machine applications.
This is a great resource to use too be sure a machine is reaching the maximum stretch rate. It is also a great way to find out if workers are reaching the proper amount of stretch when applying hand film. Use this as a method of auditing and possibly decreasing film usage.
Tools and Materials Needed
We recommend using a pallet of goods that is commonly wrapped. Remember that uniform pallet loads such as boxes will often obtain a higher stretch rate than loads with sharp edges or corners.
Ruler - Used for Drawing a straight line
Marker - Preferably a permanent marker
Tape Measure - To measure lines
Calculator - For simple math
Pen and Paper - To write down measurements
Tie the stretch film to the corner of the pallet and make one or two full revolutions around the pallet.
After the last corner is reached to complete two full revolutions, loosely pull 5-6 ft. from the stretch film roll and hold them up to the pallet.
Hold the loose stretch film up to the boxes and make 3-5 ten inch lines on the film. The lines should be spaced apart a few inches across the length of the extra film pulled out in step two. Making a ten inch line makes doing the math much easier once the test is complete. Multiple lines should be marked on the film to obtain an average rate during one revolution of pallet wrapping.
How it should look when completed
Wrap the pallet as normal after 3-5 ten inch lines are marked on it. This can be done by hand or with a machine. After the pallet is wrapped the lines should be stretched out longer than the original 10 inches.
Use a tape measure to measure the stretched lines and write each line length down.
After all of the stretched lines are measured and wrote down, get the average length of the lines by adding all lengths together and dividing by the number of lines. If the average of all of the lines is 20, a 100% stretch rate is being reached. If the average of the lines is 30 inches, a 200% stretch rate is being reached.
This is by no means a scientific method for testing the stretch rate of pallet wrap. The proper tools and equipment needed for scientific testing can be expensive. This is merely an easy way to audit film stretch rates. This will help forecast film usage as well as signal possible adjustments that may need to be made when wrapping pallets in the warehouse. Call us at 1-800-441-5090 with questions about stretch film, stretch wrap machines, or anything else related to unitized load packaging.