Wrapping bales? There are now growing number of balers which can apply film inside the chamber, designed to offer extra protection and quality. Jane Carley looks at the pros and cons.
A number of manufacturers are now offering the option of applying film in the bale chamber, either on standalone balers or combi-wrapper machines.
Net wrap has almost replaced twine tying of round bales in many parts of the country, offering a tighter package which wraps and stores well.
However, a number of manufacturers are looking to take this a stage further by applying a layer of film to the bale before it leaves the chamber rather than net.
Benefits claimed include better silage quality due to the increased oxygen barrier around the cylindrical side of the bale. Tighter wrapping of the bales using pre-stretched film also reduces bale expansion, resulting in maximum preservation and gives a better shaped bale for easier storage, say the manufacturers.
There is also the potential to reduce the number of layers of plastic applied at the final wrapping stage, since the film put on in the chamber offers more protection than net.
When unwrapping, the film is said to catch on the bale less, even after a long period of storage or in frosty conditions.Waste management is also easer with just one type of plastic for disposal, rather than plastic plus net.
No matter how bales are wrapped, bales still have to be handled in a careful and timely manner, says Rhun Fychan, silage specialist at IBERS.
Rhun Fychan, silage specialist at IBERS, comments that any development which aims to improve bale quality is welcome but cautions that reducing wraps to four layers could potentially produce a weak point on the bale shoulders, depending on the grass type.
He says; “Not every bale is perfectly shaped and poor bale shoulder shape directly affects the film seal, letting in more air and leading to spoilage.”
He suggests that film applied in the chamber needs to extend as far as possible around the edge of the bale to give sufficient protection if only four layers of wrap are used. “Six layers of film is still the most beneficial and cost effective option; it is questionable if, when feeding ruminants, the additional benefit offered by using eight layers justifies the extra cost.”
Another issue, he points out, is that even though film application in the chamber is an excellent development, the film is tensioned in a different direction to that produced by the final wrapper, which means the bond between the two films is not as strong.
Mr Fychan adds; “However, the concept of tighter bales is a positive – the tighter you can hold the bale together, the better. But remember that however good a job is done by the machinery in the field, bales still need careful and timely handling to avoid spoiled silage due to damaged plastic.”
Kuhn Farm Machinery has introduced a new version of its round baler-wrapper combination machine, the i-BIO+, featuring a patented twin film-on-film wrapping system.
The i-BIO+ is an integrated baler and wrapper with the six rollers in the bottom of the chamber acting as a wrapping table during the bale wrapping process.
Its film binding system uses two film reels to bind the cylindrical side of the bale using standard sized rolls (1,500m long, 750mm wide by 25um thick), eliminating the need to order separate binding and wrapping film. Kuhn claims its system offers quick and easy roll loading by hydraulically folding the film reels into their loading/unloading position.
A higher stretch ratio is said to offer up to 30 per cent film cost savings for film binding as well as longer intervals between the exchange of film rolls, cutting downtime.
Switching between film and net binding is said to be quick and simple as the two systems are separate.
Bale wrapping is taken care of by the manufacturer’s IntelliWrap system which gives complete control of the wrapping process, allowing the operator to select the number of film layers and to adjust film overlap. The i-BIO+’s wrapping ring allows film to be applied at up to 50 revolutions per minute.
The baler is also IsoBus compatible, with all functions managed via a colour display terminal.
Both the New Holland Roll Baler 125 Combi and Roll Baler 135 Ultra can be specified with a film-wrap system.
Designed to work in conjunction with the integral wrapping system, a hydraulic motor drives the film roll to feed the film onto the bale, compressing the film into a thin strip initially to feed it into the bale chamber.
The film arm mechanism pre-stretches the film wrap before it is rolled around the bale for consistent wrapping quality, says the manufacturer.
Net wrap can also be accommodated by the same mechanism, giving a quick switch between crops.
Product specialist Oliver James says: “For film-on-film wrapping inside our balers we use a film called Polybale Pro from our supplier Tama. We can supply the machine to apply two different widths of film; 1,280mm and 1,380mm; thickness 16um and stretch from 5-10 per cent. The wrapper uses standard 500 or 750mm film widths with a thickness of 21um.”
“Outputs are the same for film and net wrapping, and whilst the film is more expensive than the net, the initial film wrap means you are able to use fewer layers of film when doing the final wrap. This brings the overall cost to approximately the same.”
Krone’s Comprima Xtreme balers and combi wrappers can now be fitted with a film on film system and the 1.28m wide, 2,000m long and 16um thick Krone RoundWrap stretch film covers the bale from edge to edge, says the firm.
The manufacturer points out that its film system differs from others on the market as the film is not gathered before it is cut, allowing the next wrapping cycle to start immediately with the film already spread to its full width, saving time and material costs.
After the wrapping cycle is completed, the film is cut across the full bale width and is ready to be applied across the full width of the next bale. The film roll is simply replaced with net roll to switch to netwrapping.
The McHale Fusion 3 Plus integrated wrapper baler uses a patented application system for the chamber film which adjusts the breaking force on the roll of plastic to suit working conditions and allow for a continuously variable stretch.
This allows it to automatically adapt to changes in temperature during the day without the operator having to adjust any settings.
When plastic is applied to the barrel of the bale it can be stretched to approximately 20 per cent, which McHale points out is higher than can be achieved with netwrap or twine, giving a tighter, better shaped bale.
The company adds that as the plastic is being stretched as it is being applied to the barrel of the bale it expels more air than net wrap would, resulting in better silage quality. Netwrap can also be used on this baler via a simple adjustment.
Martin McHale, McHale sales and marketing director, says: “Our product design engineers have been working on our film on film system for four years. We ran a number of machines around the factory in Ballinrobe for the last few years and from what we are seeing once farmers have experienced the increased silage quality which a film on film system delivers they do not want to move back to more traditional methods.”
Vicon thinks film on film technology could potentially be a good idea for its non-stop Fast Bale round baler.
Other leading baler manufacturers are more guarded about the benefits of film on film systems.
Vicon has been developing a film wrap system for its FastBale integrated baler-wrapper for two years, and technical manager Tim Baker says that it is likely to be commercially available in 2017.
He says; “It’s hard to predict the demand for film-on-film. Speaking to contractors who are already using the system we understand that they really like the concept but have not made that many bales yet.”
“However, we believe that it would be a useful addition for the FastBale by speeding up the wrapping cycle using two-three layers of net-replacement wrap and just four layers of film.”
Mr Baker adds; “The challenge that faces manufacturers is to ensure that chamber wrapping works reliably in all conditions; there may also be a manual handling issue with loading the heavy rolls of film into the chamber to overcome.”
“If we can tackle these issues it would certainly be of benefit to FastBale users and is the next stage in its development.”
John Deere has taken bale protection in a different direction, introducing B-Wrap for storing unwrapped dry hay and straw bales outside.
Designed to reduce dry matter losses compared to netwrap, two layers of composite material protect the bale from bad weather and ground moisture offering improved bale quality and storage flexibility fully compensate for the slightly higher material cost per bale.
John Deere reckons for the extra cost of the film on film wrapping technology, it is not worth it at the moment.
The company’s hay and forage sales specialist Mike Baker comments: “Although this is a completely different technique aimed to achieve a different result to B-Wrap, John Deere is of course looking into the film on film concept. We feel we want to bring more benefits to the customer than film on film systems are currently offering.”
He points out; “There are obvious cost implications in using film in place of net wrap, i.e. around £1.00 - £1.50 per bale more expensive than net. The baler is also more expensive as it involves a much more complex net/film tying system.
“The original thought was that it would allow fewer film layers to be applied during the wrapping process that would outweigh the extra cost of film instead of net; in reality this does not offer the corners and the outside 400mm on the side of the bales sufficient coverage.
“Another negative is the amount of bales per roll of film being reduced from around 330 bales for a roll of net to about 100-150 bales, depending on humidity and temperature, Thus more rolls are required in the day the operator has to stop baling and change them more often, reducing daily output.”
Mr Baker comments on the claim that film on film makes a tighter bale as the film does not stretch like net wrap and therefore the bales hold their shape much better for longer.
“This is the case when compared to the standard practice of putting as little net wrap on as possible to save on cost because it only has to hold the bale together until it's wrapped. When film on film is applied, over twice as many layers are applied in the chamber - if the same number of layers of net are applied as film on film, the bale would also be held together just as well.”
“We believe that for all the extra cost involved the benefits are very small in comparison to the cost of film tying in place of net.”