Fiber Quality of Betung Bamboo (Dendrocalamus asper) from Forest Area with Special Purpose (FASP) Pondok Buluh, Simalungun, North Sumatera

The FASP Pondok Buluh is located in Dolok Panribuan District, Simalungan Regency, Sumatera Utara, which has uniqueness due to the number of bamboo species found in this area, such as Betung Bamboo. This bamboo has a long fiber and is suitable for pulp and paper materials. This research aims to measure the dimension of Betung Bamboo and its fiber derivatives value for the eligibility of pulp and paper material. A total of 3 stems of Betung Bamboo were cut, and samples were taken in the form of a disc with a length of 5 cm at heights of 1, 3, 5, 7, 9, 11, 13, and 15 meters. Then the sample was cut into sticks, and separated fibers were made using the maceration process. Furthermore, the dimensions of the sample were measured using a light microscope, namely fiber length, fiber diameter, and fiber wall thickness, and then the measurement for the fiber derivatives value of the bamboo fiber. The results of this research obtained the average dimension of bamboo fiber is 2402 μm for fiber length, fiber diameter is 18.18 μm, lumen diameter is 8.73 μm, and fiber wall thickness is 4.91 μm. The fiber length graph shows the decreased fiber length along the bottom to the top of the bamboo culm and the wavy trend for the fiber diameter on some bamboo heights. The measurement of the fiber derivatives values obtained the average Runkle ratio 1.15, felting power 133.63, mulhsteph ratio 76.91%, rigidity coefficient 0.27, and flexibility ratio 0.48. Then the quality class of bamboo fiber was determined. A score of 275-325 was obtained with quality class II, meaning that Betung Bamboo is grown in the Pondok Buluh area. It is suitable for use as raw material for pulp and paper because it has long fibers, is easy to flatten when milled, and has good fiber bonds.