TITLE:
Analysis of the Wood Processing Chain and Improvement of Material Yield for Sapelli, Frake and Azobe: The Case of Interbois Company of Cameroon, Littoral Region
AUTHORS:
Christelle Dadem, Jean Baurel Atchombou, Mesmine Sheilla Sontia Kenfack
KEYWORDS:
Processing Chain, Timber, Improvement, Material Yield, Interbois Company Cameroon
JOURNAL NAME:
Open Journal of Forestry,
Vol.16 No.4,
October
30,
2026
ABSTRACT: This study was carried out between February and June 2024 at the Société Interbois du Cameroun (SIBC), located in Douala 5ème. Its objective was to contribute to the analysis of the processing chain for the three timber species - Sapelli (Entandrophragma cylindricum), Frake (Terminalia superba) and Azobe (Lophira alata) - at SIBC, with a view to improving material yield. The methodological approach initially involved measuring a total of 196 logs for the three species studied: 92 for Azobé, 54 for Frake and 50 for Sapelli. These logs were selected using rational stratified sampling based on production flows over a five-month period, in accordance with ATIBT standards. Subsequently, each log was tracked; to prevent loss of traceability during cross-cutting and sorting operations, each log was individually marked at both ends with indelible paint. Dendrometric measurements were taken with the bark intact, in accordance with ATIBT volume measurement rules, in order to obtain the actual timber volume and enable an objective comparison of material yields by species. Diameter was measured using a forestry caliper in a cross-pattern (two perpendicular measurements were taken) to average out ovalisation. Finally, individual interviews were conducted with the managers of the various processing units using a semi-structured questionnaire. The results showed that the timber processing cycle at SIBC is as follows: procurement of roundwood stock, transfer of roundwood stock to the log yard, feeding of the head saw, processing of roundwood into sawn timber, inspection, storage and recording of batches of intermediate products, drying, planing and removal of batches from stock. The company has a specific yield by timber species of 33.12 per cent for Sapelli, 41.54 per cent for Frake and 38.67 per cent for Azobé, resulting in an overall material yield of 37.64 per cent with a standard deviation of (±4.33), indicating moderate variability. This variation can be explained by the differences in the technological behaviour of the different timber species: (Sapelli is a high-density, cross-grain species with the lowest yield, whilst Frake is a homogeneous species). The range of [33.31 per cent - 41.97 per cent] shows that Interbois remains below the break-even threshold set by the ATIBT standard (45 per cent). In light of these results, the development of a sawing system that takes into account log shapes and variations in the cutting line depending on the timber species could increase machine yield. Furthermore, alternative uses could also assist SIBC in the production of various items (furniture, panelling, charcoal, etc.).