Rubber - Dry Rubber Content
Dry rubber content (DRC) is the fundamental quality and pricing basis for field latex and cup lump rubber at the point of purchase from smallholders. DRC determination by the standard ASTM D3040 gravimetric method requires drying and weighing - a process that takes hours and is typically done by the processor, not the smallholder. This information asymmetry means smallholders often accept prices based on the processor's unverifiable DRC estimate. NIR-based rapid DRC measurement at collection points could rebalance this dynamic.
Findings
What We've Established
NIR Sensitivity to Dry Rubber Content
The rubber hydrocarbon backbone (C–H stretching overtones) produces strong and characteristic NIR absorption. DRC in field latex is essentially measuring the ratio of rubber polymer to water and serum, both of which have strong and separable NIR signals. Published research confirms NIR-DRC calibration performance equivalent to the gravimetric reference method.
Social Impact Dimension
Beyond the technical measurement, this project has a clear social impact angle: transparent, independent DRC measurement at the point of sale addresses a documented price fairness problem for smallholder rubber farmers across Sri Lanka and the region. This framing resonates with development finance and impact investment partners.
Methodology
Technical Approach
NIR diffuse reflectance or transflectance measurement on cup lump rubber samples or fresh latex (depending on practical constraints at collection points). PLS-R calibration against ASTM D3040 gravimetric reference DRC. Requires samples spanning the practical DRC range (typically 40–65% for cup lump) from diverse estate and smallholder sources.
Status
Where We Stand
Outreach to rubber processor and smallholder organisation contacts has been completed. Awaiting confirmed response and discussion of data collection access.
Roadmap
Next Steps
Confirm partner engagement from processor or smallholder organisation
Design portable sample presentation protocol compatible with field collection conditions
Collect initial calibration samples across the operational DRC range
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Interested in This Research?
If you have relevant data, domain expertise, or a measurement problem in this area, we're open to research collaboration and data-sharing agreements.