Hubungan sifat berat jenis dengan sifat higroskopisitas melalui pendekatan nilai rerata kehilangan air [Relationship between specific gravity and hygroscopicity through average water loss approach]

Abstrak. Sifat higroskopisitas kayu diduga berhubungan dengan nilai berat jenis (BJ) kayu. Penelitian ini bertujuan untuk mengetahui pengaruh perbedaan nilai BJ kayu sengon (Falcataria moluccana (Miq.) Barneby & J.W. Grimes), jati (Tectona grandis L. f.), merbau (Instia bijuga (Colebr.) Kuntze) dan mahoni (Swietenia mahagoni (L.) Jacq.) terhadap nilai kehilangan air saat diberi perlakuan pengeringan pada suhu 60ºC selama beberapa waktu. Sengon dan jati yang berusia muda mewakili kayu dengan BJ rendah, sedangkan mahoni dan merbau mewakili kayu dengan BJ tinggi. Hasil penelitian menunjukkan massa awal setelah perendaman dengan air selama 24 jam untuk sengon, jati, mahoni dan merbau berturut-turut adalah 5,346 g; 7,356 g; 7,366 g dan 7,469 g. Nilai BJ sengon, jati, mahoni dan merbau berturut-turut sebesar 0,294; 0,511; 0,625 dan 0,733. Pengukuran kehilangan air yang dilakukan selama 7,5 jam menunjukkan nilai rerata kehilangan air total untuk sengon, jati, mahoni dan merbau berturut-turut adalah 2,431 g; 2,440 g; 2,363 g dan 1,560 g. Uji lanjut Tukey menunjukkan bahwa nilai BJ antar keempat spesies tersebut berbeda nyata. Uji lanjut Tukey untuk nilai rerata kehilangan air selama 7,5 jam tidak berbeda nyata antara sengon, jati dan mahoni namun berbeda nyata antara sengon, jati dan mahoni dengan merbau.Kata Kunci: berat jenis; kehilangan air; hubunganAbstract. Hygroscopicity of wood is related to specific gravity (SG). This research was aimed to understand the relationship between specific gravity of sengon (Falcataria moluccana (Miq.) Barne by & J.W. Grimes), jati (Tectona grandis L. f.), merbau (Intsia bijuga (Colebr.) Kuntze) and mahoni (Swietenia mahagoni (L.) Jacq.) through their water loss from heat treatment. Results showed that SG of sengon, jati, mahoni and merbau were 0.294; 0.511; 0.625 and 0.733 respectively. Measurements of water loss performed for 7.5 hours at 60ºC for sengon, jati, mahoni and merbau were 2.431 g; 2.440 g; 2.363 g and 1.560 g. Tukey’s test showed that the SGs among wood species were significantly different. Tukey’s test for average water loss was not significantly different between sengon, jati and mahoni, but significantly different between sengon, jati and mahoni and merbau. Keywords : specific gravity; relationship; water los

The artistic properties of rosewood (Dalbergia latifolia Roxb.) as a reference for the development of decorative veneers and synthetic vinyl.

Research on the basic characteristics of sonokeling wood (Dalbergia latifolia Roxb.) has not been carried out widely. These properties include texture, pattern and color. This research aims to study and recognize these characteristics as a consideration of potential utilization of sonokeling wood to be developed widely. One simple technique in diversifying beauty of this wood was by drying treatment and visual photography technology combination. The research results showed that sonokeling wood had a very clear difference between heartwood and sapwood, and the growth rings are clearly visible. The wood texture is rather rough, especially at sapwood. The texture is rather smooth and shiny on heartwood. The pattern is very clear with beautiful black lines. The pattern is an embodiment of anatomical, chemical characteristics and radial section appearance of sawn wood. In production of decorative veneer, pattern will appear maximal in veneer slicing technique. Average color value (E) of sapwood = 63.54 (brown-yellowish brown) while heartwood = 32.28 (dark brown-blackish brown). Sonokeling wood is worthy to be widely developed considering of its beautiful patterns and colors, especially for product diversification of decorative veneers and synthetic vinyl. So that sonokeling wood become one of popular wood, especially in Java Island

ANATOMICAL INVESTIGATION OF FIVE GENERA THE LEAST-KNOWN TIMBER OF APOCYNACEAE AND THEIR POTENTIAL UTILIZATION

Doubtlessly, wood identification is critically important for a number of sectors, including government organizations, the wooden-based industry, museums, law enforcement, and scientists working in botany, ecology, forestry, and wood technology. Unfortunately, most wood species listed as “the least-known species” lack essential knowledge or their anatomical features and basic properties to promote their usage. This research aimed to investigate the anatomical characteristics and fiber quality of the least-known timber species of Apocynaceae family, which are authentic wood collection from Xylarium Bogoriense, namely, Ervatamia sphaerocarpa, E. aurantiaca, Kopsia flavida, Lepiniopsis ternatensis, Plumeria acuminata, P. rubra, and Voacanga foetida. Wood samples have indistinct growth ring boundaries, diffuse-porous vessels in diagonal and/or radial pattern, vessels in radial multiples of 4 or more cells, simple perforation plate, alternate intervessel pits; distinct borders of vessel-ray pits, similar with those of intervessel pits in size and shape throughout the ray cell, and septate fibers with simple pits to minutely bordered pits which are common in radial and tangential walls. Based on the fiber length and the derived values of fiber dimension, some species are classified into Quality Class II and III, and the rest of them are classified into Quality Class II or III for pulp and paper manufacturing. Based on general characteristics, commonly Apocynaceae can be used as handicrafts raw material. Based on the fiber quality, some species which are classified into Quality Class II, are predicted to have potential as pulp and paper material with medium quality

Pengaruh Pengeringan Terhadap Perubahan Warna, Penyusutan Tebal, Dan Pengurangan Berat Empat Jenis Bambu

Warna permukaan batang bambu berubah secara alami akibat kondisi disekitarnya. Tulisan ini mempelajari Perubahan warna permukaan bambu akibat pengeringan dalam ruangan (KU) dan dalam oven (KO). Perubahan warna empat jenis bambu yaitu mayan (Gigantochloa robusta Kurz.), ater (Gigantochloa atter (Hassk) Kurz. ex. Munro), ampel kuning (Bambusa vulgaris var striata), dan wulung (Gigantochloa atroviolacea Widjaja) dipelajari bersama dengan korelasinya terhadap kehilangan air. Pengukuran warna dilakukan menggunakan metode CIE-Lab sedangkan kehilangan air mengacu pada pengukuran susut tebal dan kehilangan berat selama KU dan KO. Hasil penelitian memperlihatkan bahwa terdapat hubungan yang erat antara kehilangan air dengan Perubahan warna batang bambu. Kehilangan air bambu mayan, ater, dan wulung menunjukkan korelasi linier positif terhadap Perubahan warna permukaan bambu, dimana semakin besar kehilangan air maka semakin besar pula nilai Perubahan warnanya. Namun, pada bambu ampel kuning, semakin besar kehilangan air maka akan semakin kecil nilai Perubahan warnanya (berkorelasi negatif). Hal ini disebabkan warna alami bambu ampel kuning pada kondisi segar tidak jauh berbeda dengan warna setelah pengeringan. Perlakuan pengeringan dalam ruangan, susut tebal terbesar adalah mayan = 46,03%; kehilangan berat terbesar adalah ampel kuning = 28,52%; dan Perubahan warna (ΔE*) terbesar adalah ater = 15,51%. Perlakuan pengeringan dalam oven, susut tebal terbesar adalah mayan=52,4%; kehilangan berat terbesar adalah ampel kuning = 31,19%; dan ΔE* terbesar adalah ater = 18,8%

Pengaruh Pengeringan Terhadap Perubahan Warna, Penyusutan Tebal, Dan Pengurangan Berat Empat Jenis Bambu

Warna permukaan batang bambu berubah secara alami akibat kondisi disekitarnya. Tulisan ini mempelajari Perubahan warna permukaan bambu akibat pengeringan dalam ruangan (KU) dan dalam oven (KO). Perubahan warna empat jenis bambu yaitu mayan (Gigantochloa robusta Kurz.), ater (Gigantochloa atter (Hassk) Kurz. ex. Munro), ampel kuning (Bambusa vulgaris var striata), dan wulung (Gigantochloa atroviolacea Widjaja) dipelajari bersama dengan korelasinya terhadap kehilangan air. Pengukuran warna dilakukan menggunakan metode CIE-Lab sedangkan kehilangan air mengacu pada pengukuran susut tebal dan kehilangan berat selama KU dan KO. Hasil penelitian memperlihatkan bahwa terdapat hubungan yang erat antara kehilangan air dengan Perubahan warna batang bambu. Kehilangan air bambu mayan, ater, dan wulung menunjukkan korelasi linier positif terhadap Perubahan warna permukaan bambu, dimana semakin besar kehilangan air maka semakin besar pula nilai Perubahan warnanya. Namun, pada bambu ampel kuning, semakin besar kehilangan air maka akan semakin kecil nilai Perubahan warnanya (berkorelasi negatif). Hal ini disebabkan warna alami bambu ampel kuning pada kondisi segar tidak jauh berbeda dengan warna setelah pengeringan. Perlakuan pengeringan dalam ruangan, susut tebal terbesar adalah mayan = 46,03%; kehilangan berat terbesar adalah ampel kuning = 28,52%; dan Perubahan warna (ΔE*) terbesar adalah ater = 15,51%. Perlakuan pengeringan dalam oven, susut tebal terbesar adalah mayan=52,4%; kehilangan berat terbesar adalah ampel kuning = 31,19%; dan ΔE* terbesar adalah ater = 18,8%

Hubungan Sifat Berat Jenis Dengan Sifat Higroskopisitas Melalui Pendekatan Nilai Rerata Kehilangan Air [Relationship Between Specific Gravity and Hygroscopicity Through Average Water Loss Approach]

. Sifat higroskopisitas kayu diduga berhubungan dengan nilai berat jenis (BJ) kayu. Penelitian ini bertujuan untuk mengetahui pengaruh perbedaan nilai BJ kayu sengon (Falcataria moluccana (Miq.) Barneby & J.W. Grimes), jati (Tectona grandis L. f.), merbau (Instia bijuga (Colebr.) Kuntze) dan mahoni (Swietenia mahagoni (L.) Jacq.) terhadap nilai kehilangan air saat diberi perlakuan pengeringan pada suhu 60ºC selama beberapa waktu. Sengon dan jati yang berusia muda mewakili kayu dengan BJ rendah, sedangkan mahoni dan merbau mewakili kayu dengan BJ tinggi. Hasil penelitian menunjukkan massa awal setelah perendaman dengan air selama 24 jam untuk sengon, jati, mahoni dan merbau berturut-turut adalah 5,346 g; 7,356 g; 7,366 g dan 7,469 g. Nilai BJ sengon, jati, mahoni dan merbau berturut-turut sebesar 0,294; 0,511; 0,625 dan 0,733. Pengukuran kehilangan air yang dilakukan selama 7,5 jam menunjukkan nilai rerata kehilangan air total untuk sengon, jati, mahoni dan merbau berturut-turut adalah 2,431 g; 2,440 g; 2,363 g dan 1,560 g. Uji lanjut Tukey menunjukkan bahwa nilai BJ antar keempat spesies tersebut berbeda nyata. Uji lanjut Tukey untuk nilai rerata kehilangan air selama 7,5 jam tidak berbeda nyata antara sengon, jati dan mahoni namun berbeda nyata antara sengon, jati dan mahoni dengan merbau

Fixation Process of Laminated Bamboo Compression From Curved Cross-section Slats

Removing the outer part of bamboo for manufacturing flat bamboo lamination has disadvantage on the density of the product. The purpose of this experiment was to investigate the fixation of compressed bamboo from curved cross-section slats. The compression of bamboo slats using densification technique was aimed for uniform density. Furthermore, steam treatments were conducted to fix the deformation. The compressed bamboo slats revealed that the density of the samples at the bottom parts increased from 0.40–0.56 g/cm3 to 0.89–1.05 g/cm3 after pressing with a compression level between 46.98–63.97%, while the samples in the middle parts increased from 0.70–0.83 g/cm3 to 1.02–1.18 g/cm3 with the compression level of 32.92–41.50%. These results were slightly higher than that of the upper parts, which was between 0.91–0.98 g/cm3. The recovery of set decreased and the weight loss increased with increasing temperature and steam treatment time. Fixation of compressive deformation could be achieved at 160°C within 60 minutes. The bottom parts of samples experienced a slightly greater weight loss compared to the middle parts, i.e. 8.38% and 7.49%, respectively. The anatomical structure of bamboo tended to deform during densification process. Furthermore, the steam treatments affected the colour of densified bamboo which became darker. From this experiment, it can be concluded that the manufacture of laminated bamboo from bamboo slats can be uniformed in strength by equalizing the density at the bottom and middle with the upper parts through the densification technique. However, further research should be conducted to know the delamination and shear strength of the bamboo lamination

Bending Strength Of Lignocellulosic Materials In Softening Condition

This research aimed to understand the softening behaviour and viscoelastic property of wood, rattan, and bamboo as lignocellulosic materials. Nine years-old Fast growing teak wood [Tectona grandis L.f.], rattan [Calamus sp.], and 3 years-old andong bamboo [Gigantochloa pseudoarundinaceae (Steud.) Widjaja] were used for the experiments. The samples were taken from the bottom, middle and upper parts for wood and rattan, and that for bamboo were cut from the 1st to 20th internodes. Static bending tests were carried out in fresh (green) as control samples, air-dried, and softened by microwave heating (MW) for 1 min to determine modulus of rupture (MOR) and modulus of elasticity (MOE). The results showed that the MOR and MOE values of wood, rattan, and bamboo increased from fresh to air-dried condition, and decreased by MW. When compared at the same density, drastic increase was observed for the normalized MOR value in air-dried of rattan, i.e. 2.5 fold. However, the decreasing of all the normalized MOR values were almost the same, i.e. 0.5 fold when they were softened by MW. Remarkably increase was also appeared for the normalized MOE value in air-dried of rattan, i.e. 3.0 fold and decreased to almost zero by MW. These results indicated that rattan was more easily bent, followed by bamboo and then wood. Hydrothermal properties of chemical components significantly affected the changes of strength (MOR) and elastic properties (MOE). However, the differences in bending strength of wood, rattan, and bamboo were more likely due to differences in their anatomical structures