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STABILISASI DIMENSI PADA KAYU TANAMAN KARRI (Eucalyptus diversicolor) DAN JARRAH (E. marginata) - Bagian II : Furfurilasi (Dimensional Stabilization on Regrowth Karri (Eucalyptus diversicolor) and Jarrah (E. marginata) Part II : Furfurylation Jamal Balfas
Jurnal Penelitian Hasil Hutan Vol 11, No 4 (1993): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.1993.11.4.134-136

Wood blocks of karri and jarrah measuring 10 mm (radial) x 25 mm (longitudinal) x 100 mm (tarigential) were ovendried for. 48 hours at 105°C prior to treatment. Furfurylation was carried out by soaking wood specimens in a 98. % furfuryl alcohol solution containing 1 % (w/w) of ZnCl2 as catalist. Three soaking times, i.e., 12, 24 and 48 hours were used. Treatment results are expressed in terms of weight (WG) and volumetric (VG) gains. The ability of treatment to dimensionally stabilize wood blocks is expressed as anti- swelling efficiency (ASE). Results showed that furfurylation imparted substantial increase in weight, volume and dimensional stability of both regrowth eucalypts. Alike acetylation (reported earlier in Part I),furfurylation on karri specimens revealed higher weight gain,volumetric gain and ASE than jarrah. The rate of furfurylation significantly increased with increasing soaking time to 48 hours. Although furfurylation imparted a high degree of swelling reductions comparable to those obtained by acetylation, the furfurylated specimens and a lower ability to resist swelling during prolonged wetting exposure.

KETEGUHAN REKAT RESORSINOL FORMALDEHIDA PADA KAYU YANG DIA WETKAN DENGAN CELCURE Jamal Balfas
Jurnal Penelitian Hasil Hutan Vol 13, No 1 (1995): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.1995.13.1.9-18

Production of laminated structural timbers suitable for use under severe conditions dates back to the development of resorcinol and phenol-resorcinol adhesives. These adhesives could provide highly durable bonds with untreated wood. Because preservative treatment of the - wood is commonly required, it became necessary to investigate the effect of the treatment on glue bond strength.This study examined the shear strength of resorcinol formaldehyde on the untreated and cetcure treated timbers. Additionally, a mechanical and a chemical surface activation treat- ments were imposed lo the system prior lo gluing. Species included for the study were: jeungjing (Paraserianthes falcataria (L.) Nielsen, adinandra (Adinandra brasii Kobuski) and pala burung (Horsfieldia sylvestris Warrb.). Defect-free airdried wood slicks measuring 50 mm (radial) x 50 mm (tangential) x 500 mm (longitudinal) were divided into two groups, of which one group was celcure-treated using an empty-cell process and the other was remained as control. Each slick was then cut into billets for adhesive lamination. Surface activation treatments were made mechanically by sanding wood surface with an 80-grit abrasive paper, or chemically by smearing wood surface with IM solution of NaOH approximately 24 h before gluing. Resorcinol formaldehyde was applied to each surface at a spread rate of 120 mg/cm2. Panels were clamped at 12 kg/cm2 for 7 h as recommended by the adhesive manufacturer. Each panel was cut into four shear specimens, of which two specimens were tested in dry condition and the remaining after 24 h immersion in water at room temperature. Strength loss due to wetting was also determined.Results showed that bond strength of resorcinol formaldehyde varied according to wood species. Jeungjing had a weaker bond strength than adinandra and pala burung. Preservative treatment had no deteriorating effects on dry shear strength, but it did reduce the wet shear strength of wood laminates. The application of surface activation treatments was more effective on the higher extractive contained species (adinandra and pala burung) and the unpreserved laminates. Surface mechanical treatment showed a better improvement on bond strength than the chemical treatment. Jeungjing experienced a higher strength loss during immersion than

PENGARUH PENGERASAN MATA GERGAJI TERHADAP BEBERAPA SIFAT PENGGERGAJIAN Osly Rachman; Jamal Balfas
Jurnal Penelitian Hasil Hutan Vol 5, No 5 (1988): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.1988.5.5.279-286

Fifteen mahogany and six agathis logs in fresh cut condition were sawn into boards by a band saw machine. Each wood species was sawn using three saw blades with different cutting edge hardness i.e. hand swaging, alternate stellite . tipping and full stellite tipping. Sawing properties recorded include power consumption, cutting rate and sawing productivity for each wood species and cutting edge hardness.The results of study showed that wood species had no significant difference in terms of power consumption and cutting rate. Meanwhile, sawing productivity of agathis was higher than mahogany.Furthermore, the cutting edge hardnes had significant effect on sawing properties. It is found that the saw blade with alternate stellite tipping reduced power consumption, and increased the cutting rate and productivity.

SIFAT PEMESINAN BEBERAPA JENIS KAYU ASAL JAMBI Jamal Balfas
Jurnal Penelitian Hasil Hutan Vol 12, No 4 (1994): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.1994.12.4.128-131

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.

SIFAT PEMESINAN BEBERAPA JENIS KAYU ASAL JAMBI Jamal Balfas
Jurnal Penelitian Hasil Hutan Vol 12, No 4 (1994): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

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.

PENENTUAN PENUMPULAN PISAU PADA PERMUKAAN KAYU Jamal Balfas
Jurnal Penelitian Hasil Hutan Vol 10, No 4 (1992): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.1992.10.4.66-69

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.

HUBUNGAN ANTARA KONSUMSI TENAGA DAN KECEPATAN PEMBELAHAN Jamal Balfas
Jurnal Penelitian Hasil Hutan Vol 6, No 3 (1989): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.1989.6.3.209-211

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.

PENGARUH UMUR POHON, POSISI BATANG, TEBAL VENIR DAN KOMPOSISI PANEL INTI SAWIT TERHADAP PRODUKSI KAYU LAPIS MINDI Jamal Balfas; Jamaludin Malik
Jurnal Penelitian Hasil Hutan Vol 38, No 3 (2020): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.2020.38.3.189-198

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.

FURFURILASI PADA KAYU TUSAM (Pinus merkusii Jungh. et de Vr.) DAN MANGIUM (Acacia mangium Willd.) Jamal Balfas
Jurnal Penelitian Hasil Hutan Vol 13, No 5 (1995): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.1995.13.5.176-185

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.

PENETAPAN UKURAN SASARAN SEBAGAI USAHA PENINGKATAN EFISIENSI PROSES PENGGERGAJIAN Osly Rachman; Jamal Balfas
Jurnal Penelitian Hasil Hutan Vol 6, No 4 (1989): Jurnal Penelitian Hasil Hutan
Publisher : Pusat Penelitian dan Pengembangan Hasil Hutan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.1989.6.4.215-219

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.

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