How To Test Stretch Film Stretch Rate
Stretch film is a plastic film used to secure, bundle, and stabilize products. Stretch film is made from linear low-density polyethylene. When applying the film is to be pulled and stretched around products to obtain tight and secured product loads. Stretch film comes in a variety of widths, thicknesses and colors.
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.
Steps To Test Stretch Film Stretch Rate
Tools and Materials Needed
Stanley Packaging experts 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.
Calculator – For simple math
Marker – Preferably a permanent marker
Tape Measure – To measure lines
Pen and Paper – To write down measurements
Ruler – Used for Drawing a straight line
- 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 wrap.
- 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.
- 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.