Lynne Wong's PhD thesis

Sucrose % cane and fibre % cane
16
fibre % cane
14
sucrose % cane
12
sucrose / fibre ratio in cane
10
1960 1970 1980 1990 2000
2.5
2.0
1.5
1.0
0.5
Sucrose / fibre ratio in cane
Figure 1.6. Changes in fibre % cane, sucrose % cane and sucrose/fibre
ratio in cane from 1960-2004.
1.4.1.1 Fibre % cane
The true cane fibre content varies with cane varieties and climatic conditions, such as
cyclones and drought, and although there were variations in fibre % cane in the premechanization
era of 1960-1975, the average of 13.2% showed that the true cane fibre had
remained constant in spite of changes in varietal composition of the cane crushed.
Since increased mechanization started in 1975 with grab loading of manually harvested
cane to lorry, fibre % cane no longer represents the true cane fibre. It also includes the
fibrous material from trash and the soil from cane, reflecting to some extent the extraneous
matter in cane received at the factory. Changes in fibre % cane from 1975 to 1996 (see Fig
1.6) represent an increase of 2.0 units, and correspond to the upward trend in the extent of
mechanical loading. In 1990, when mechanical loading of cane was at 50% of the total
production and when the amount of mechanical harvesting was still insignificant, fibre %
cane was at 14.7, i.e. 1.5 units higher than the previous 13.2 fibre % cane.
In general, a higher fibre content of the raw material due to more cane trash reduces mill
capacity, increases power consumption and causes more wear and tear of the equipment.
From Fig 1.6, it is evident that the upward trend in fibre % cane seems to have levelled off
since 1996. The increase in 1999 was due to the high proportion of immature cane sent to
factories together with cane tops, and dry and green leaves with adhering soil, because of
the most severe drought ever faced by the country during that year. A clean cane
13