Below are basic bale wrapping best practices.
Handle bale wrap with care.
Handling balewrap recklessly will damage the plastic very easily, making it impossible to unwrap the stretch film properly.
In hot weather:
Keep the roll boxed and in a shaded area until needed. This will limit excess tack coming out of the plastic. Balewrap that is very tacky will cause tack build up on the stretch unit rollers, and result in the film "over stretch", reducing your protection result.
Keep the rollers clean:
Some tack will inevitably stick to the pre-stretch rollers. Clean regularly using white spirit. In very hot weather it may be necessary to clean more often. Dirty rollers will affect stretch percentage, cause uneven application and too much neck down on the bale.
To measure that the correct amount of stretch is being achieved, mark or tape two points 10 inches apart on the roll, after pulling the wrap through the pre-stretcher. Measure the distance once the wrap has been applied to the bale. For conventional film, 50% stretch would mean a reading of 15 inches. 60% equals a reading of 16 inches on the bale. Measuring neckdown after stretch should not be lower than 24 inches (for 600mm), 22.8 inches (for 580mm) and not lower than 16 inches (for 500mm).
Always wrap bales within 2 hours of baling:
If wrapping individual bales in the field, move bales to the stack immediately after wrapping.
Follow the machinery
manufacturer's recommendations for set-up:
On single bale wrappers, make sure that the center of the bale and center of the roll of film are horizontally aligned. Take into account different bale sizes and adjust the height of the PSU accordingly. To ensure that 6 layers of film are applied, count the number of revolutions it takes to completely cover the bale once. Add one more and multiply by 3.
For example, if it takes 7 revolutions to cover the bale once, add 1 (making 8 in total) and multiply by 3. Therefore, 24 revolutions are needed to apply 6 layers of film. On in-line wrappers, the number of layers applied is adjusted by altering the number of inches the bale is moved forward per revolution of the hoop. To apply 6 layers on an in-line wrapper (with 2 pre-stretchers) using a 30 inch (750mm) roll of film, adjust to a 4 inch movement. After stretch, the film width is +/- 24 inches divided by 6 layers will equal 4 inches apart.
NOTE: As bales vary in both size and shape, extra turns may be necessary to achieve correct film application.
Use a hydraulic type grab for handling bales, even before they are wrapped:
Remove bales from the field as soon as possible. When stacking single bales,
stand the bales on their end, as there is more plastic to protect the bales from rough ground and bird damage.