Rattans, the climbing palms of tropical countries, offer an important alternative to wood for various end-uses and livelihood to many rural and tribal populations. Little scientific information is available about the effect of processing practices such as oil curing, bleaching and fumigation of rattans on their utilization value. With this purpose, the processing practices were standardised and their effect on the mechanical properties were investigated.
It was found that oil curing in kerosine doesn't adversely affect the bending strength (MOR) stiffness (MOE) and density. But the compressive strength (MCS) is found slightly affected.
The bending (MOR) and compressive (MCS) strength as well as density were found not adversely affected due to fumigation of air-dried round rod rattans. For rattan peels, the maximum tensile strength (MTS) was reduced to the extent of 28-31% due to fumigation. The tensile strength of rattan peels of different species were almost reduced to half of its original value due to bleaching. It was found that for round rod rattans, bleaching in green condition with 7.5% solution for 12 hours is ideal for good colour development and doesn't adversely affect the mechanical properties such as bending (MOR), stiffness (MOE) and compressive (MCS) strengths as well as density.
Considering the beneficial effect of improvement in skin colour and the immediate reduction in moisture content resulting improved resistance towards fungal degradation and since this is no adverse effect on the bending strength, kerosine curing is highly recommendable to the rattan processing industry and will definitely add value to the end-products such as furniture and fixtures. In processing applications where bleaching and fumigation of rattans is unavoidable, it should be applied to round rod rattans only. Products made with bleached or fumigated rattan peels are likely to behave with inferior mechanical properties.
Key words: Rattan processing, oil curing, fumigation and bleaching, mechanical properties.
Correspondence: T.K. Dhamodaran, Kerala Forest Research Institute, Peechi 680 653, Kerala, India
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