SOFT CANES AND THEIR IMPACT ON THE FACTORY

IN 2016, THREE new cane varieties, SRA1A, SRA4A and QC04-1411, were either released or were proposed for release into the Bundaberg and Mackay districts. According to the pre-release fibre quality measurements undertaken by Sugar Research Australia, all three varieties were classified as soft canes. This paper summarises the results of a series of experiments undertaken to better define soft canes and to measure the effect that these three varieties had on factory operation and performance. SRA1A had a low fibre content of typically 10% and an impact resistance lower than the minimum criterion considered for normal canes. The other two varieties, SRA4A and QC04-1411 had relatively normal fibre contents of about 14%. While their impact resistance was low, it was still within the normal range. The shear strength of all three varieties were within the normal range, with SRA1A having the lowest values. The final fibre quality parameter, short fibre content, has a defined normal range up to 65%. QC04-1411 has a particularly high short fibre content and SRA4A’s results were also around 65%. SRA1A’s results were mostly less than 65% but also higher than any of the established varieties. The low fibre content of SRA1A is considered the biggest problem regarding the processing of the three varieties. All three varieties exhibited the soft cane characteristic of generating low mill torques. Associated with the inability to maintain torque set points, bagasse moisture contents from the soft canes were found to be higher than normal. This result was particularly pronounced with SRA1A, where Isis and Millaquin recorded increases in final bagasse moisture content of between three and eight units. While the yield of some of the soft cane supplies was measured to be quite high, those yield benefits need to be weighed up against the additional factory processing costs that will be incurred in terms of capital upgrades and stops.