Judul: The Effect of Adhesive Content and Wood Species to the Physical and Mechanical Properties of Small Scale and Full Scale OSB Made From Two Species of Community Forest Timber
Abstrak: Dewasa ini, produksi kayu bulat dari hutan alam Indonesia mengalami penurunan, sedangkan kebutuhan kayu semakin meningkat. Berbagai cara telah dilakukan untuk memenuhi kebutuhan kayu tersebut, salah satunya adalah dengan memanfaatkan jenis-jenis kayu dari hutan rakyat. Kayu yang berasal dari hutan rakyat memiliki kualitas yang kurang baik karena umumnya berdiameter kecil dan mengandung banyak kayu juvenil. Menurunnya kualitas kayu tersebut membuat produk komposit menjadi suatu alternatif. Salah satu produk komposit yang sedang populer adalah papan strand berorientasi (oriented strand board) atau yang lebih dikenal dengan OSB. OSB merupakan panel dari strand kayu yang direkat dengan perekat tipe eksterior dan dikempa panas. Penelitian mengenai pemanfaatan kayu rakyat sebagai bahan baku OSB telah banyak dilakukan. Samosir (2008) dalam penelitiannya mendapatkan bahwa kombinasi OSB terbaik adalah OSB dengan face yang terbuat dari kayu manii dan core dari kayu akasia. Tujuan penelitian ini adalah untuk menerangkan pengaruh perbedaan kadar perekat dan pencampuran strand kayu akasia dan manii dalam pembuatan OSB terhadap sifat fisis dan mekanisnya dan menentukan perlakuan yang dapat memberikan sifat terbaik terhadap OSB yang dihasilkan. Pengujian sifat fisis mekanis papan merujuk pada standar JIS A 5908 (2003) tentang papan partikel dan standar CSA 0437.0 (Grade O-2) tentang OSB. Variabel yang digunakan dalam penelitian ini adalah jenis kayu dan kadar perekat yang digunakan. Kayu akasia, manii dan campuran digunakan sebagai bahan baku pembuatan OSB. Kadar perekat yang digunakan adalah 5% dan 7% dengan penambahan parafin sebanyak 1%. Parameter sifat fisis dan mekanis yang diamati meliputi kerapatan, kadar air, daya serap air, pengembangan tebal, modulus lentur (MOE), modulus patah (MOR), kekuatan rekat (internal bond) dan kuat pegang sekrup. Berdasarkan pengujian sifat fisis terhadap OSB kecil yang dibuat didapatkan nilai sebagai berikut: nilai rata-rata kerapatan OSB hasil penelitian berkisar antara 0,49-0,56 g/cm3, nilai rata-rata kadar air OSB hasil penelitian berkisar antara 7,96-8,65%, nilai rata-rata daya serap air OSB 2 jam berkisar antara 6,25-12,98%, nilai rata-rata daya serap air OSB 24 jam berkisar antara 32,46-52,02%, nilai rata-rata pengembangan tebal OSB 2 jam hasil penelitian berkisar antara 1,46-6,26%, nilai rata-rata pengembangan tebal OSB 24 jam hasil penelitian berkisar antara 6,34-21,30%. Sedangkan pengujian sifat mekanis menghasilkan data sebagai berikut: nilai rata-rata MOE kering sejajar serat OSB hasil penelitian berkisar antara 30.215- 49.773 kg/cm2, nilai rata-rata MOE kering tegak lurus serat OSB hasil penelitian berkisar antara 9.096-13.356 kg/cm2, nilai rata-rata MOE basah sejajar serat OSB hasil penelitian berkisar antara 11.006-26.358 kg/cm2, nilai rata-rata MOE basah tegak lurus serat OSB hasil penelitian berkisar antara 3.208-8.276 kg/cm2, nilai rata-rata MOR kering sejajar serat OSB hasil penelitian berkisar antara 222,7- 388,5 kg/cm2, nilai rata-rata MOR kering tegak lurus serat OSB hasil penelitian berkisar antara 100,4-178,7 kg/cm2, nilai rata-rata MOR basah sejajar serat OSB hasil penelitian berkisar antara 121,5-206,3 kg/cm2, nilai rata-rata MOR basah tegak lurus serat OSB hasil penelitian berkisar antara 42,7-90,9 kg/cm2, nilai ratarata kekuatan rekat OSB hasil penelitian berkisar antara 3,54-6,88 kg/cm2, nilai rata-rata kuat pegang sekrup OSB hasil penelitian berkisar antara 40,07-49,83 kg. Perlakuan pemakaian jenis kayu yang berbeda (kayu manii, kayu akasia dan campuran keduanya) dalam pembuatan OSB dapat mempengaruhi nilai sifat fisis dan mekanis OSB. Nilai sifat fisis yang tidak
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Judul: Pengaruh Kombinasi Strand, Kadar Perekat dan Beda Tekanan terhadap Sifat Fisis Mekanis Oriented Strand Board Kayu Mangium dan Afrika.
Abstrak: INTRODUCTION. Overexploitation for decades affecting reduction of round wood production from Indonesian natural forest, in the other hand round wood demands are increasing. This quality decline supporting composite products as an alternative. One of popular composite products is oriented strand board or commonly known as OSB. OSB is a panel from wood strand and compound with exterior adhesive and then hot pressed. There were many observation regarding for OSB made from community forest’s wood. The objectives of this research are to explain adhesive difference, acacia and african wood combination strand and difference of pressing on OSB manufacturing to its physical and mechanical properties and to determine the best treatment for OSB. Physical and mechanical properties test is refer to JIS A 5908 (2003) standard of particle board standard and CSA 0437.0 (Grade O-2) standard of OSB. MATERIAL AND METHOD. Variable used were wood species, adhesive content, and pressing. Mangium, African and mix of them used as OSB raw materials. Adhesive content used were 6%, 8% with 1% parafin added. Physical and mechanical properties observed were density, moisture content, water absorption, thickness swelling, modullus of elasticity (MOE), modullus of rupture (MOR), internal bonding and screw holding power. RESULTS. The average value resulted from physical properties test are : OSB’s average density about 0,50-0,62 g/cm3, the average moisture content is about 7,61-11,23%, water absorption average of OSB 2 hours is about 24,12-73,12%, water absorption average of OSB 24 hours is about 56,57-115,97%, the average value of thickness swelling OSB 2 hours is about 9,39-32,35%, the average value of thickness swelling OSB 24 hours is about 17,44-36,04%. The average value resulted from mechanical properties test are : the average dry MOE parallel to grain is about 21.518-39.019 kg/cm2, the average dry MOE perpendicular to grain is about 6.134-12.363 kg/cm2, the average wet MOE parallel to grain is about 3.435-22.278 kg/cm2, the average wet MOE perpendicullar to grain is about 2.078-8.316 kg/cm2, the average dry MOR parallel to grain is about 158,71-346,67 kg/cm2, the average dry MOR perpendicullar to grain is about 82,66-160,40 kg/cm2, the average wet MOR parallel to grain is about 52,12-223,22 kg/cm2, the average wet MOR perpendicullar to grain is about 34,66-135,61 kg/cm2, the average OSB internal bonding is about 1,24-7,72 kg/cm2, the average screw holding power is about 33,85-73,13 kg. OSB from Mangium wood with 8% of adhesive content and 25 kg/cm² is the finest OSB. Wheter, OSB from African wood with 6% of adhesive content, and pressing of 15 kg/cm² is the worst OSB. Wood species which gives the best effect is Mangium, followed by african wood and combination of them as the worst. The best adhesive content is 8% while the best pressing is 25 kg/cm².
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Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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