Keeping an eye on module wraps (17 April 2019)

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Maintaining Australia’s reputation for clean cotton requires focus on how we handle new technology in round module harvesters. 

The Australian cotton industry is known for its rapid uptake of technology and research. Paradoxically, recent technological and engineering breakthroughs have not only revolutionised the industry, they’ve also brought with them new considerations.

On-farm, the introduction and rapid adoption of John Deere’s 7760 and the later models CP690 and CS690 round module harvesters is one such instance; changing harvesting but also raising considerations around the polyethylene wrap on the modules.

Australia outstrips the rest of the world collectively in the uptake of these machines. Released in 2008, by the 2010-2011 season there were approximately 80 JD 7760 machines in Australia that harvested approximately 44 percent of the 4.2 million bale crop. Just 12 months later, there were more than 200 machines harvesting approximately 75 percent of the (5.4 million bale) crop. Today between 90 and 95 percent of the crop is harvested with these machines. By comparison, about 50 percent of the US crop is currently harvested by John Deere round module harvesters.

The reasons, beyond Australian growers’ keen uptake of technology and efficiency drive, are varied.

“It’s taken a bit longer to take off in the US, this is mainly due to the size and scale of their industry, amount of existing equipment and the diverse nature of farming all of which makes it harder to change practices,” CottonInfo Fibre Quality Technical Lead René van der Sluijs said.

 “Also a large percentage of cotton in the US is stripped instead of picked, and the release of the CS690 stripper in 2014 certainly assisted in the increased uptake.”

While improving efficiency by reducing labour and machinery requirements dramatically, new contamination scenarios due to the plastic wrap are a reality. On average, 2710 metric tons or 15 million metres of plastic is used annually wrapping Australian cotton. Each round module wrap is 21 metres and weighs about 3.8 kg.

Even if a tiny piece of that wrap makes its way into round modules then turnout bales, it can cause issues for spinners and go on to adversely affect the appearance of yarn, fabric and the final product.

 “It’s the number one problem for manufacturers of high-quality cotton products overseas and has serious impacts on ginners’ time and productivity here in Australia,” René said.

 “According to the International Textile Manufacturers Federation, the degree of fibre contamination varies widely from country to country and region to region and is related to different farming, harvesting and ginning practices.

“Australian cotton has the international reputation of being among the cleanest and least contaminated, and we need to keep it that way.”

The plastic wrap can find its way into the round modules via machine/wrap malfunction, operator mismanagement, poor loading and transportation. Sometimes the contamination is obvious, in other instances the ‘tail’ or a tear may find its way into the centre of the module.

Sharp focus on plastic wrap contamination is a must to maintain Australia’s reputation for clean cotton. Vigilance while harvesting and transporting is the key to avoiding contamination.

The Australian Cotton Ginners Association (ACGA) members are the first to deal with plastic wrap contamination – at the gin. In an effort to detect contamination, gin sensors were developed with the Association and CSIRO with support from CRDC, however nothing is better than a preventative.

ACGA chair, Andrew Vanderstok, said ginners were very aware of the issue, which is a headache for them, is time-consuming and disruptive to the ginning process.

“Good on-farm practices is a key factor and also transportation prior to the ginning process,” he says.

“If there is some sort of problem with the wrap mechanism and it is not detected or correctly dealt with by the operator, this puts the responsibility on the ginner to remove any contaminants prior to ginning.

“We get reports of the ‘tail’ of the (previous) wrap being found in the middle of a module, and tears along the edges of the modules.

“John Deere released a new guide last year, and I would encourage all machine owners to make sure drivers have read and understand it.

“Trying to iron out the issue of wrap malfunctions during the building process should be a priority.

“Making sure machine operators have inductions and are trained to be on the lookout for wrap malfunctions is essential.”

Spotlight spoke to several ginners and growers who said they seen a pattern of plastic wrap contamination based on the sequence of the wraps on the roll.

Brighann Ginning’s head ginner Damian Tonkin said they’ve seen patterns emerge during some ginning seasons.

“There are 24 wraps in a roll and there is an RFID tag for every wrap, so when we find this large piece or ‘tail’ as they call it in the module, we can find the RFID tag on that piece,” he said.

“In one instance we found that the piece of wrap was always numbered 24 which indicates it was the last wrap on the roll on a particular machine.

“From what I have been told from the grower, the operator was doing something wrong when it comes to changing from one roll to the next roll in the magazine.

“The operator needs to be aware that this can happen and need to be properly trained to operate the machine.”

Damian said the installation of gin sensors has been helpful, but not infallible.

“If we detect plastic in cotton it requires a total shutdown and trace back through the full system as it breaks up and moves quickly.”

Start on farm

“Once a country has achieved a reputation for contamination, the likelihood of it achieving base world market prices is slim and growers are usually heavily discounted ranging from five to 30 percent even if the fibre quality is acceptable,” René said.

“The first and most logical step to address the problem of contamination is to prevent/avoid or minimise the contamination entering the production process, particularly during growing, harvesting and ginning.”

René recommends that growers:

  • Store rolls of plastic wrap in their original packaging in an enclosed shed to avoid exposure to direct sunlight and moisture.
  • Ensure that the harvester is set-up according to the Operators Manual and regular cleaning and servicing is conducted before, during and after harvesting has been completed. Take care that the wrap components are clean and free from debris.
  • Use only trained and skilled drivers to operate harvesters.
  • Tag modules and notify the ginner of any potential bale wrap encountered during harvesting.
  • Stage modules on high, flat and well drained areas of bare soil and as per the method of transport and storage at the gin.
  • Repair significant wrap tears in the field prior to loading on the module truck to prevent further wrap damage and ginning problems.
  • Secure loose outer tails with 3M Hi-strength 90 spray adhesive or lint bale
    repair tape.
  • Ensure that any chain beds used are fitted with rounded cleats, so that the chains will not puncture the plastic wrap.
  • Ensure that modules are loaded without piercing the module wrap.
  • Make all workers aware of the consequences of contamination. Provide workers with the tools to clean up and isolate rubbish. Use only white cleaning rags.

This article appears in the Autumn 2019 edition of CRDC's Spotlight magazine.