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<![CDATA[SIFAT PEMESINAN BEBERAPA JENIS KAYU ASAL JAMBI ]]>
<![CDATA[Jamal Balfas]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 12, No 4 (1994): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.1994.12.4.128-131
<![CDATA[Five wood species originated from Jambi were observed for their machining properties in this study. Sawing characteristics (feed speed and surface smoothness) of each species were observed to determine its cutting-ability. Sawn timbers were then cut to sample boards and air-seasoned to approximately 17% moisture content prior to further machining processes. The examined machining properties include planing, shaping, boring, turning and sanding. Examinations were undergone according 10 the modified ASTM D-1666 as firstly described in the Forest Products Research Institute Report No. 160 (1982).Results from this study showed that most of the species could be sawn at medium feed speed with a variation in cutting surface quality, ranging from fair to rough. One species, i.e., rengas pantai (Gluta renghas) is fairly difficult to saw for its irregular (partly interlocked) grain orientation and the abundant deposition of silica (crystals) in its fiber structures. Some species consistently showed good qualities in almost all machining tests, and likely produced excel/en/ surface quality when worked on using sharp culling tools and controlled machining condition. Wood samples tested in wet condition produced a fairly good planing and shaping quality for most wood species. In comparison, however, the air-dried samples significantly revealed a better machining quality. Based on the machining characteristics observed on the five wood species from Jambi, it is recommend able to use rengas tembaga, sumpung and rengas manuk for wood working purposes. Whereas, rengas pantai and kempas are more suitably intended for indoor structural uses.]]>
<![CDATA[PENENTUAN PENUMPULAN PISAU PADA PERMUKAAN KAYU ]]>
<![CDATA[Jamal Balfas]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 10, No 4 (1992): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.1992.10.4.66-69
<![CDATA[The wear of wood cutting tools. is. generally, the process which makes a usable tool unfit for continued use. The replacement of the worn cutter by reconditioning or substitution of a new one represents a necessary cost which can be minimized by controlling tool wear. Numerous studies have been conducted through direct observations on the cutting edge using a variety of photographic methods. Such observations are quite complicated and can hardly be introduced to industrial practices. This study is aimed to explore a possibility of determining cutting tool wear indirectly through the work piece observation. It is based on assumption that knife blunting has a direct bearing on the quality of the finished product, i.e., changing the geometry of cutting marks on the wood surface.Boards of two wood species, rasamala and mangium, were seasoned to air-dry condition and planed using new sharp knives at one feed speed of 30 .m/min. Observations were carried out sequentially at 5 pianing distances, i.e., 10, 20, 40, 80 and 160 m. Cutting marks geometry on the wood surface was distinguished by rubbing the surface gently with a carbon paper. Measurements of cutting marks and the width of cutting peak were undertaken using a digital calliper. Results showed that values of cutting marks and width of catting peaks markedly increased with increasing planing distances. Blunting process was significantly affected by wood species. Knives used for planing rasamala boards blunied quicker than those used for mangium. These, to some extend, revealed a possible use of cutting marks structure on wood surface for determining the wear of cutting edge.]]>
<![CDATA[HUBUNGAN ANTARA KONSUMSI TENAGA DAN KECEPATAN PEMBELAHAN ]]>
<![CDATA[Jamal Balfas]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 6, No 3 (1989): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.1989.6.3.209-211
<![CDATA[Eighteen logs of several wood species were used as material for the above study. Each log was sawn on a 44 inch Band Headrig with automatic carriage. Specifications of machine and sawblade used are listed in table 2. Sawing velocity was determined by the ampleness of cutting area per unit cutting time on every sawing line. Whereas the power consumption was detected by the ampere-meter set on the motor electric circuit. The ampere value is then transformed to the power consumption unit (Watt-second/cm2). The result of statistical calculation revealed a close relationship between power consumption and sawing velocity. Power consumption can be estimated from the sawing velocity in accordance with the regression equation : Y = 82.97 -0.118 X. The correlation is negative and almost perpect (correlation coefficient r = - 0.908). This means that, power consumption will increase if sawing velocity decreases, and vice versa.]]>
<![CDATA[PENGARUH UMUR POHON, POSISI BATANG, TEBAL VENIR DAN KOMPOSISI PANEL INTI SAWIT TERHADAP PRODUKSI KAYU LAPIS MINDI ]]>
<![CDATA[Jamal Balfas]]>;
<![CDATA[Jamaludin Malik]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 38, No 3 (2020): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.2020.38.3.189-198
<![CDATA[Penelitian ini menguji pengaruh umur pohon, posisi batang, tebal venir, dan komposisi inti panel kayu sawit terhadap produksi kayu lapis mindi. Dolok berukuran panjang 1,3 m dipotong dari pohon sawit berumur 25 dan 32 tahun masing-masing empat batang kayu dari setiap pohon sejumlah sepuluh pohon dari masing-masing kelas umur. Selanjutnya dikupas pada mesin spindle less rotary dengan ketebalan venir 2,5 dan 3,4 mm. Venir sawit kering (KA 10%) dirakit menjadi dua macam komposisi panel, yaitu 3 lapis dan 5 lapis, di mana lapisan muka dan belakang menggunakan 1,2 mm venir kayu mindi (Melia azedarach). Hasil penelitian menunjukkan bahwa batang sawit umur 32 tahun memiliki nilai rendemen venir basah maupun kering lebih tinggi daripada batang sawit umur 25 tahun. Kadar air dan kerapatan panel kayu lapis mindi berinti sawit umur 25 tahun memiliki nilai lebih rendah daripada umur 32 tahun. Nilai keteguhan rekat panel yang terbuat dari venir inti 32 tahun memiliki nilai yang lebih tinggi daripada venir inti 25 tahun. Keteguhan rekat panel 3 lapis memiliki nilai lebih tinggi daripada panel 5 lapis. Keteguhan rekat pada panel yang terbuat dari venir 2,5 mm lebih rendah dibandingkan dengan keteguhan rekat panel dengan ketebalan venir 3,4 mm.]]>
<![CDATA[FURFURILASI PADA KAYU TUSAM (Pinus merkusii Jungh. et de Vr.) DAN MANGIUM (Acacia mangium Willd.) ]]>
<![CDATA[Jamal Balfas]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 13, No 5 (1995): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.1995.13.5.176-185
<![CDATA[Wood specimens of tusam (Pinus merkusii Jungh. et de Vr.) and mangium (Acaciamangium Willd.) were air-dried to approximately16-18% moisture content. One group of the specimens was further oven-dried ttJ reach moisture content of 6-8%. Furfurylation was undertaken by soaking wood specimens/or 24 hours in a 98%.furfuryl alcohol solution containing 0.35% (vlv) of ZnCl2 as catalyst. Furfurylated specimens were then cured at 1 OO°C for 48 hours. Wood characteristics observed in this study include dimentional stability, hardness, compression strength and shear strength.Test results showed that the initial wood specimens of tusam had a higher radial but a lower tangential swelling rates than those specimens of mangium. Furfurylation could improve wood dimentional stability of both species by more than 90% on tusam and 75% on mangium.Values of hardness, compression strength and shear strength of tusam were markedly lower than mangium. After furfurylation, however, tusam had a greater hardness than mangium. Furfurylation could increase hardness, compression strength and shear strength of tusam by more than 94%, 83% and 76% respectively. A lower wood mechanical improvements were encountered with the mangium specimens.]]>
<![CDATA[PENETAPAN UKURAN SASARAN SEBAGAI USAHA PENINGKATAN EFISIENSI PROSES PENGGERGAJIAN ]]>
<![CDATA[Osly Rachman]]>;
<![CDATA[Jamal Balfas]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 6, No 4 (1989): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.1989.6.4.215-219
<![CDATA[Two units of sawmill in Lampung (Sumatera) and three units in West-Java have been visited for the purpose of this study. Determination of target size on each sawmill was firstly done by collecting data from thickness measurements of 100 board samples. The data was then calculated using the most common formulas used for determining the lumber target size.The result of the study revealed that actual size produced by two sawmills surveyed were higher than target size, ranging from 1.08 to 1.58 mm. The actual size from three other sawmills were lower than target size, ranging from 0.26 to 2.18 mm. The sawmill A has apparently the best sawing capability. This was indicated by the smallest thickness range either within or between board i.e. 0.89 mm and 0. 79 mm. Meanwhile, its total sawing variation was smallest i.e. 0.49 mm.The result of this study was an indication that there is a need for improving the efficiency of sawing process through the application of target size determination.]]>
<![CDATA[PENGARUH PERACUNAN TRIKLOPIR DAN POLA PENGGERGAJIAN TERHADAP SIFAT PENGGERGAJIAN KAYU RASAMALA (ALTINGIA EXCELSA NORONHA) ]]>
<![CDATA[Osly Rachman]]>;
<![CDATA[Jamal Balfas]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 6, No 5 (1989): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.1989.6.5.292-298
<![CDATA[The objective of this study is to determine the sawing properties of triclopyr poisoned rasamala logs compared to the girdled and normal ones. The effect of sawing pattern on sawing properties were also observed.The log samples used in this experiment comprise of 18 pieces which were collected from three different groups of tree (poisoned and girdled in one year periode, and control). Six logs of each group were sawn in two sawing patterns, namely live sawing and semi-quarter sawing. Parameters of sawing observed include recovery, productivity, power con- sumption, and sawn timber defects, particulary splits and bowing.The results of study revealed that moisture content of poisoned logs was 20% lower than the normal one. Mean-while, both moisture content of girdled logs and poisoned ones are not significantly diferent. Poisoning treatment on rasamala trees in comparison to girdled and normal ones did not show significant difference in any sawing properties, except sawing productivity. The sawing recovery, power consumption, splits and bowing of sawn timber were 62%; 32.37 watt sec./cm2, 5.21 cm and 3.91 cm, respectively. The live sawing could increase the pro- ductivity as much as 0.18 m3 /hour higher than semi-quarter sawing.]]>
<![CDATA[PENENTUAN PENUMPULAN PISAU PADA PERMUKAAN KAYU ]]>
<![CDATA[Jamal Balfas]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 12, No 2 (1994): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.1994.12.2.109-113
<![CDATA[The wear of wood cutting tools is, generally, the process which makes a usable tool unfit for continued use. The replacement of the worn cutter either by reconditioning or substitution of a new one represents a necessary cost which can be minimized by controlling tool wear. Numerous studies have been conducted through direct observations on the cutting edge using a variety of photographic methods. Such observations are quite complicated and can hardly be introduced to industrial practices. This study is aimed to explore a possibility of determining cutting tool wear indirectly through the work piece observation. It is based on assumption that knife blunting has a direct bearing on the quality of the finished product, i.e., changing the geometry of cutting marks on the wood surface.Boards of two wood species, rasamala and mangium, were seasoned to air-dry condition and planed using new sharp knives at one feed speed of 30 m/min. Observations were carried out sequentially at 5 planing distances, i.e., 10, 20, 40, 80 and 160 m. Cutting marks geometry on the wood surface was distinguished by rubbing the surface gently with a carbon paper. Measurements of cutting marks and the width of cutting peak were undertaken using a digital calliper. Results showed that values of cutting marks and width of cutting peaks markedly increased with increasing planing distances. Blunting process was significantly affected by wood species. Knives used for planing rasamala boards blunted quicker than those used for mangium. These, to some extend, revealed a possible use of cutting marks structure on wood surface for determining the wear of cutting edge.]]>
<![CDATA[SIFAT PENGGERGAJIAN DAN PEMESINAN ENAM JENIS KAYU HTI ]]>
<![CDATA[Jamal Balfas]]>;
<![CDATA[Osly Rachman Rachman]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 6, No 5 (1989): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.1989.6.5.343-346
<![CDATA[This paper presented the result of study on sawing and machining properties of six Indonesian wood species being developed as raw materials for the wood working industries. The sawing properties studied comprise of sawn timber recovery, sawing velocity and power consumption. Whereas the machining properties of the timber were tested according to the modified ASTM D-1666 as described in the Forest Products Research Institute Report No. 160 (1982).The result showed that all of the species has good sawn timber recovery, i.e. more than 50%. Three of them can be cut eastiy wilh higher sawing velocity and lower power consumption in comparison with the other three. The species that have good or very good machining properties is merkuyung (Shorea johorensis). Species of meranti merah (Shorea fallax) has relatively poor machining properties. Whereas the other four species are good in some properties and fair to poor in others.]]>
<![CDATA[PENGARUH EKSTRAKSI DAN PENGERINGAN TERHADAP DERAJAT PEMBAHASAN PERMUKAAN DAN KETEGUHAN REKATAN KAYU (The effect of extraction and oven-drying on wood surface wettability and bond strength) ]]>
<![CDATA[Jamal Balfas]]>
<![CDATA[ Jurnal Penelitian Hasil Hutan Vol 11, No 6 (1993): Jurnal Penelitian Hasil Hutan ]]>
Publisher : <![CDATA[Pusat Penelitian dan Pengembangan Hasil Hutan ]]>
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DOI: 10.20886/jphh.1993.11.6.222-227
<![CDATA[Wood blocks measuring 10 min (radial) x 25 mm (tongitudinal) of regrowth karri (eucalyptus diversicolor F. musfi.) and jarrah (E.marginata ex sm.) were used in this study. The extraction treatment was preceded by a preliminary experiment to determine the effect of extraction on percentage weight loss of wood blocks and extractive yield. Five extraction times were used, 8,16,32,64 and 128 hours, further experiments were undertaken to investigate the effects of oven-drying hot-water extraction an a combination of the two treatments on wattability and shear strength of karri and jarrah laminates, panels were made by gluing pairs of laminates with resorcinol formaldehyde at a spread rate of 1.2 mg/mm2. The preliminary experiment showed that water soluble extractives removed from wood blocks increased with increasing time of extraction. The amount of extractives removed was approximately three times greater is karri than in jarrah. Extending the extraction period beyond 32 hours resulted in collapse, bowing and checking of the wood blocks during drying. Results from the initial experiments revealed that either oven drying, extraction or the combination of the two treatments have all significantly (p<0.01) reduced wettability and shear strength of the wood laminates. There was no significant relationship between wettability and shear strength for both regrowth eucalyptus.]]>
