A baler-wrapper with a fixed bale chamber produces round bales of approximately 1.3 m in diameter. A baler-wrapper with a variable bale chamber can bale and wrap bales up to 1.6 m in diameter. This flexibility can be extremely useful, and a larger bale diameter can result in a lower cost per ton of forage.
A round bale with a larger diameter: a calculation example
Take a bale of 1.3 m in diameter and 1.2 m wide that is bound with three effective layers of film, then wrapped with six layers of film. The three effective layers of film binding cost €1.27 with the KUHN TWIN-reel system. This calculation is based on standard wrapping film rolls of 1500 metres that cost €99 each. The six wrapping layers cost a total of €4.50 for film. This adds up to a total cost per bale of €5.77 for film.
If the same calculation is made for bales with a diameter of 1.45 m, the costs for film binding are €1.38 and the six layers of film for wrapping are €5.37 per bale. This brings the total cost of binding and wrapping a bale to €6.75. This is an increase of 17% compared with the 1.3 m diameter bale. However, in this case the volume of crop in one bale is higher. A 1.3 m bale converts to 1593 litres, while a bale of 1.45 m in diameter has a volume of 1982 litres: that is 24% more crop per bale. If you calculate the costs of film per cubic metre, the result is €3.62 and € 3.41 per m3 of crop respectively. That represents a saving of 6 %. A bale of 1.6 m in diameter has a volume of no less than 2413 litres. So, the savings are even higher! In total, 13 % lower costs for film per m3. However, in practice it is more difficult to transport bales of 1.6 m and they can be quite heavy.
Calculation example 1.45 / 1.6 m bale diameter compared with 1.3 m
|Bale diameter||Bale volume||Increase in bale volume compared with 1.3 m||Film used per bale||Film costs per m3||Bale handling costs||Output|
|1.3 m||1.59 m3||–||–||–||–||–|
|1.45 m||1.98 m3||+ 24%||+ 17%||– 6%||– 20%||+ 3%|
|1.6 m||2.41 m3||+ 51%||+ 31%||– 13%||– 34%||+ 4%|
Table 1: Calculation example difference 1.45 / 1.60 m bale diameter compared with 1.3 m bale diameter
Save film and time
Let’s take a farmer who produces 2000 silage bales with a diameter of 1.3 m per year as an example. If this farmer decides to produce 1.45 m diameter bales using a variable baler-wrapper, the same volume of silage will fit into approximately 1600 bales. That converts to 400 bales fewer a year.
The total savings on film for this farmer are €688 a year.
An additional benefit is 400 fewer bales that need to be loaded, transported and stacked, plus the baler operator can stop 400 fewer times a year to bind and eject a bale. And as less film is used, the total number of times the film must be changed on the binder and wrapper is significantly lower.
Advantages of a larger bale diameter:
- Saves on net and film costs
- Using less net and film reduces the time spent on changing net and film
- Fewer stops to bind and eject bales
- Fewer bales to load, transport and stack
- Save costs with a smart approach to wrapping
- Fixed chamber or variable chamber, which baler is best for me?
- How to exchange wrapping film rolls on a baler-wrapper?