Netwrap construction
The thinner SHUSS tapes do not support the expansion pressure of the bale; they only maintain the correct spacing of the FRANZE tapes.This can be demonstrated in this way – If the thinner SHUSS tapes are cut from the netwrap on the bale, the bale will remain intact.
The weight of the Netwrap per metre (g/m) is not related to how strong the Netwrap is.
Higher specific strength polymers, used in the manufacturing of the net, can allow the same, or even greater strength. This can make a lighter weight roll, with the same guaranteed length, from less plastic.
Bale formation
It is important that the bale shape is uniform, and flat across its surface. Un-even shaped bales will cause the Netwrap to be under greater pressure.
Net application
It is important that the netwrap is only applied on the OUTER surface of the bale. If crop is still being picked up as the Netwrap begins feeding into the baler, some of the Netwrap will be INSIDE the bale and not ON THE SURFACE.
If some of the Netwrap is ON THE INSIDE of the bale, it will create numerous problems:-
Bale damage
It is important that the bale comes out of the baler immediately that the tailgate is opened, to avoid any damage to the Netwrap on the bale surface caused by the spinning rollers in the chamber.
This is a common problem with any baler that has rollers in the bale chamber and on ALL types of Netwrap.
CAUSE
SOLUTIONS
Crop type
Dry, cereal crop creates more pressure on the Netwrap than a grass Hay or Silage bale
A bigger diameter bale gives MORE PRESSURE on the net and will require MORE turns of net on the bale.
Correct amount of Netwrap on the bale
It is important that the correct amount of net is applied to the bale, which can vary
depending upon a number of factors
It is also important to be sure that the amount of netwrap selected by the baler-monitor, in the tractor cab, is equal to the actual number of wraps applied to the surface of the bale. Many times, the amount of Netwrap on the bale surface is not what is programmed.
It is important that the correct number of wraps of Netwrap is applied to the bale, depending upon the recommended application for the particular crop.
For best baling results, it is recommended to follow this general guide.
The numbers are MINIMUM recommended layers of netwrap, on the whole surface of the bale.
Silage 1.2m Diameter Bales |
Hay 1.5m Diameter Bales |
Straw 2.0 – 1.8m diameter Bales |
At least 2.5 full wraps on the bale surface |
At least 3.5 full wraps on the bale surface |
At least 4.0 full wraps on the bale surface |
At least one more extra wrap of net is recommended when used in extreme conditions,
such as:
!A combination of several extreme conditions may require a further increase in wraps.
These recommendations are provided as a guide. If using standard or generic Netwrap, an increase of one wrap is likely necessary to secure the bale.
Additional recommendations before and during baling:
All round balers require the same basic parameters to operate successfully with Netwrap
Feeding system
Most balers have a system of rubber and steel rollers, with adjusting settings at each side.
It is important that both sides are adjusted equally, providing full and uniform feeding pressure between the rollers.
A simple check can be made to make sure the rollers are adjusted correctly and are fully parallel. Place a single sheet of paper between the rollers and turn rollers to pull the paper between.
Tension system
All balers need to create tension on the Netwrap as it is feeding, to be sure the netwrap will:
It is critical that the braking system is correctly adjusted and working, to ensure full and uniform tension across the full width of the Netwrap.
Depending upon the baler type and model, the Tension System could be:
A. Spring-tension metal bar, pushing onto the Netwrap roll surface (Claas; McHale etc.)
B. Braking mechanism against the Feeding Rollers (John Deere etc..)
C. Disc brake and brake pad, which grips inside the card core of the Netrwap roll (Case IH; Krone; New Holland; Welger etc…)
Here are examples of the typical brake systems on common baler types and the important points to check:
Ensure that tension brake bar is flat and in contact with full width of Netwrap roll
Brake tension can be increased by more shims behind the fixing plate.
Also – be sure to check the feeding rollers are adjusted uniformly (see previous section – Feeding System)
Ensure that brake pad is not worn out, to ensure good braking efficiency
On Krone baler (picture on RIGHT) ensure the netwrap brake arm is in position and adjusted per operator manual
All types of Netwrap will have operating problems at some time.
Mostly this is due to baling or crop conditions, or perhaps a mis-adjustment of the baler.
Below are a list of the most common Netwrap problems with recommended actions to find a solution.
Net not feeding
Net wrapping on feed rollers
Net not spreading
Bales Bursting