Stretch-film consumption from roll mass change
Weighing the same stretch-film roll before and after a controlled trial can measure material consumed without converting stretched film length back into purchased length. Keep the core and weighing arrangement unchanged, and account for discarded film separately from the film left on the loads.
Define the trial before weighing
MSF20805C is cast machine stretch film listed at 20 inches wide, 5,000 feet long and 80 gauge, supplied as one roll. These are roll specifications. They do not establish a film mass per pallet, core weight or measured containment result for the operation.
Use the approved equipment and wrapping process for the trial. Record the load group and count, starting roll identification and measurement units. Use a suitable scale and a consistent weighing method that can resolve the change being measured. Remove or retain accessories consistently at both weighings.
Let the unchanged core cancel
In a hypothetical trial, the same roll and core weigh 12,000 grams before use and 10,800 grams afterward. The difference is 1,200 grams. Because the same core remains in both measurements, its unchanged mass cancels in the subtraction.
That shortcut does not apply if the before and after measurements contain different cores, loose packaging or different attached hardware. If the trial crosses a roll change, keep separate records for each roll and account for each change explicitly.
| Quantity | Calculation |
|---|---|
| Film consumed from supply | 12,000 − 10,800 = 1,200 grams |
| Discarded film collected during trial | 50 grams |
| Film retained on the ten loads | 1,200 − 50 = 1,150 grams |
| Consumption per load | 120 grams from supply; 115 grams retained |
Use the right figure for the purchase question
Supply consumption includes the material that becomes scrap. Using only the 115-gram retained figure would leave out five grams per load from this trial's purchasing consumption. Keep startup waste and any rewrapping in the stated accounting boundary so they are neither omitted nor added twice.
Record whether every trial load met the operation's approval criteria. Material use alone cannot determine whether a wrapping arrangement is acceptable. Keep the completed-load evaluation beside the consumption record.
Compare repeatable conditions
Repeat the measurement when the film, load group or approved process changes. A different mixture of load sizes can change the average without any change in the film itself. Use the cast machine stretch film buying guide for product selection, and carry measured consumption into replenishment without treating a nominal gauge or roll length as a finished-load result.