Pengaruh Modifikasi Steam dan Pembilasan NaOH terhadap Keasaman Enam Jenis Bambu

Perlakuan steam dan bilas NaOH 1% telah diketahui meningkatkan sifat fisis dan mekanis Oriented Strand Board (OSB) bambu. Peningkatan tersebut disebabkan oleh menurunnya kadar zat ekstraktif dan komponen berbobot molekul rendah lainnya pada bambu. Selain itu, steam dan bilas NaOH 1% juga diduga mempengaruhi keasaman bambu. Penelitian ini bertujuan untuk menentukan perubahan keasaman yang terjadi akibat perlakuan steam dan bilas NaOH 1% pada enam jenis bambu Indonesia. Enam jenis bambu meliputi bambu andong, betung, tali, ampel, kuning, dan hitam digunakan pada penelitian ini. Sampel bambu dicacah hingga berbentuk partikel dan diberikan dua perlakuan berbeda yaitu steam dan steam + bilas NaOH 1%. Partikel bambu kemudian digiling hingga didapatkan serbuk berukuran 40-60 mesh. Serbuk bambu diekstrak dengan air panas selama 1 jam. Nilai pH filtrat ekstrak diukur menggunakan pH meter. Ekstrak kemudian dititrasi dengan larutan H2SO4 0,025 N hingga pH 4 dan larutan NaOH 0,025 N hingga pH 10. Jumlah larutan penyangga yang ditambahkan ke dalam ekstrak dinyatakan sebagai kapasitas penyangga asam dan basa. Hasil penelitian menunjukkan bahwa jenis bambu dan perlakuan berpengaruh terhadap nilai pH dan kapasitas penyangga. Nilai rata-rata pH enam jenis bambu berkisar 5,20-6,67 dan meningkat setelah perlakuan steam dan Steam + bilas NaOH 1% berturut-turut menjadi 5,97-6,78 dan 7,02-7,63. Kapasitas penyangga asam dan basa enam jenis bambu masing-masing berkisar 0.404-0.525 mmeq dan 0.095-0.1750 mmeq dan meningkat setelah perlakuan steam dan Steam + bilas NaOH 1%.

Pengaruh Jenis Perekat terhadap Sifat Papan Partikel dari Campuran Limbah Vinir Sengon dan Bagas Sorgum

Limbah industri perkayuan dan pertanian memiliki potensi untuk dijadikan bahan baku dalam pembuatan papan partikel. Penelitian ini bertujuan untuk mengetahui pengaruh jenis perekat terhadap sifat fisis dan mekanis papan partikel. Papan partikel dibuat dengan menggunakan perekat 10% urea formaldehida (UF), 10% fenol formaldehida (PF) dan 20% asam sitrat (CA). Komposisi campuran bahan baku partikel vinir sengon dan bagas sorgum yang digunakan dalam penelitian ini adalah 25:75 berdasarkan berat. Karakteristik papan partikel diuji secara fisis dan mekanis berdasarkan standar JIS A 5908:2003. Hasil penelitian ini menunjukkan bahwa sifat fisis terbaik dimiliki oleh papan yang dibuat dengan perekat CA. Sementara itu, sifat mekanis terbaik dimiliki oleh papan yang dibuat dengan perekat UF. Berdasarkan hasil penelitian, kadar air, pengembangan tebal, keteguhan patah, dan keteguhan rekat papan partikel telah memenuhi standar JIS A 5908:2003 untuk papan partikel.

Keteguhan Rekat Kayu Lapis Sengon Menggunakan Perekat Lignin-Formaldehida dengan Dua Macam Bahan Pengisi (Bonding Strength of Sengon Plywood Using Lignin-Formaldehyde Adhesive with Two Types of Fillers)

Various efforts have been done to reduce the cost, such as finding a suitable mixture of fillers in the adhesive formulation. The aim of this study was to determine the characteristic of lignin-formaldehyde (LF) adhesive and the effect of different content of coconut shell flour and kaolin in the adhesive of lignin on the bonding strength of sengon plywood. Coconut shell flour and kaolin filler content were varied, i.e. 0%, 10%, 20%, 30%, and 40%. The plywood of (20x20x1.5) cm3 size was prepared using a liquid lignin-formaldehyde (LF) with a glue spread of 170 g m-2 surfaces. Bonding strength of plywood was tested to determine the quality of sengon plywood. The results showed that LF adhesive was appeared as a reddish-brown liquid and there were no foreign substances, solid resin content ranges from 31.85 to 35.68%, viscosity of 1.2 poise, acidity (pH) of 11.5, and gelatinized time ranges from 24.20-25.96 minutes. The type and filler content had a significant effect on the bonding strength of sengon plywood. Increasing of the filler content tended to increase the bonding strength of sengon plywood to 30%. The bonding strength of sengon plywood produced using the content of either coconut shell or kaolin flour fillers up to 30% complied with German Standards requirement. The maximum bonding strength value was obtained on adhesives using both types of fillers as much as 10 %.

Sifat Fisis dan Mekanis Oriented Strand Board Hibrida Bambu Pada Berbagai Shelling Ratio (Physical and Mechanical Properties of Hybrid Bamboo Oriented Strand Board at Various Shelling Ratios)

Hybrid Bamboo Oriented Strand Boards (OSB) were produced to improve bamboo OSB's physical and mechanical properties. Shelling ratio adjustment of the strand type combination could determine the optimal physical and mechanical properties of hybrid bamboo oriented strand boards (OSB). The purpose of this study was to evaluate the physical and mechanical properties of hybrid betung and andong bamboos OSB at various shelling ratios. Steam modified strands of betung and andong bamboo were used as an outer layer and core layer, respectively. Hybrid bamboo OSBs were prepared with 0.7 g cm-3 target density and 8% phenol-formaldehyde resin content. Three layers of OSB were made with outer: core shelling ratios of 30:70, 40:60, 50:50, and 60:40. The physical and mechanical properties of the OSB were tested referring to the JIS A 5908-2003 standard. The targeted board density was achieved and the physical properties of all hybrid bamboo OSB have met the requirement of CSA O437.0 (Grade O-1) standard criteria. The parallel modulus of elasticity (MOE) and modulus of rupture (MOR) increased with increasing outer layer ratio. However, the perpendicular MOE and MOR decreased with increasing outer layer ratio. The internal bonding (IB) of the OSB with a shelling ratio of 30:70 and 40:60 met with the requirement of the CSA O437.0 (Grade O-1) standard.

Peningkatan Kerapatan Kayu Samama Melalui Pre-kompresi Asam Sitrat (Density Improvement of Samama Wood by Pre-compression of Citric Acid)

Samama wood (Anthocephalus macrophyllus (Roxb.) Havil.) is a potential fast-growing species of Sulawesi and Maluku. This study aimed to increase the density of the wood through citric acid pre-compression. The temperature/time pressing formula and the optimal concentration of citric acid for fixation were also determined. Water saturated samples of (5x5x4) cm3 (L = longitudinal x T = tangential x R = radial) were pre-compressed at 100 °C for one hour to reach drying set. Subsquently, the samples were soaked for 4 hours in a citric acid solution of 5% and 10% concentration, drained and wrapped in aluminum foil before re-pressed at 180 °C for 10, 20, 30, 40, 50, and 60 minutes. Fixation was measured by soaking the samples into water for 24 hours at room temperature. The results showed that the moisture contents at fiber saturation point ranged from 33.15-33.94%, with density of 0.46 g cm-3 and oven dry density of 0.37 g cm-3. The L, T, and R shrinkages were 0.18-0.20%, 4.13-4.14%, and 2.53-3.10%, respectively; while the T/R ratio was 1.33-1.63%. Pre-compression can only be done at a compression target of 25% with compression level of 19.57-20.01%. Pre-compression increased the oven dry density of 17.11-20.13% to 0.44-0.45 g cm-3. After thickness recovery, the weight of the oven dried samples increased by 1.79-2.72% at the 5% citric acid concentration and by 12.04-15.25% at the 10% citric acid concentration. Permanent fixation achieved at 180 °C for 50 minutes pressing time with 10% citric acid concentration.

Potensi Tiga Jenis Kayu Tanah Gambut Sumatera sebagai Bahan Baku Pulp dan Kertas (The Potential of Three Peat Land Woods of Sumatera as Pulp and Paper Raw Material)

The growth of pulp and paper industries has encouraged the expansion of the industrial plantation forests for pulp wood. The exotic species planted for pulp wood initially maintained a relatively high productivity, however it decreases in the following rotation cycles. The peat land wood species of Sumatera could be an alternative for exotic species. However, the insufficient information on the wood properties has brought about they are less considered. This paper examined the fiber quality of Sumatran local peat-wood and its possibility as a raw material of pulp and paper. For specific gravity, samples were selected based on three different diameter groups in each plot. Fiber properties (dimension and fiber derivative values) used to asses the suitability of the wood for pulp and paper raw material were determined in accordance with the method of the Forest Product Laboratory (FPL). The resulted data and information were compared to those of krasikarpa (Acacia crassicarpa Benth.). The results showed that the fiber quality of sekubung wood was classified into grade II, while gerunggang and mahang putih were classified into grade III. The specific gravity of gerunggang wood was higher than these of other woods and comparable to that of krasikarpa. Although the growth of Sumatran local peat-wood is still low, however, conformity with government regulations (Government Regulation Number 57-2016 and Ministry of Environment and Forestry Regulation Number 17-2017) and fiber quality, the local peat-wood could potentially substitute the exotic wood species.

Profil Suhu dan Kadar Air Kayu dalam Pengeringan Oven Pemanas dan Gelombang Mikro (Temperature and Moisture Content Profiles of Woods in Heating and Microwave Ovens Drying)

This research aimed to evaluate the profile of temperature and moisture content in Pinus oocarpa wood being dried with heating oven and microwave oven. The size of samples were (25x70x120) mm3. The temperature profiles in heating oven and microwave oven drying were taken every 10 minutes and 0.5 minutes, respectively. The moisture profiles in heating oven and microwave oven drying were made in every 24 hours and 10 minutes, respectively. The heating oven was set at 60 °C, while microwave oven was set for 2 minutes intermittently with 5 minutes break. In microwave drying, the temperature inside the boards increased faster and higher compared to that in the heating oven, which resulted in a faster moisture movement to the board’s surface. The drying rate of pine increased 48-72 times in microwave compared to that in heating oven. The moisture content in the centre of boards being dried in heating oven was much higher than that of in the outer parts. On the other hand, the moisture profile in the woods being dried in microwave oven distributed more evenly.

Distribusi, Retensi, dan Penetrasi Bahan Pengawet Ekstrak Daun Tuba (Derris elliptica Benth) pada Kayu Kemiri dan Kayu Agathis (Distribution, Retention, and Penetration of Tuba Leaves Extract (Derris elliptica Benth) on Aleurites moluccana and Agathis Wood)

Wood preservation is carried out to increase the service life of wood with low natural durability. Factors such as wood structure, preservatives, and methods of preservation influence the preservation processes. The aim of this study was to evaluate retention, penetration, and distribution of tuba (Derris elliptica) leaves extract into the candlenut wood (Aleurites molluccana) and agathis (Agathis sp.) wood structures. The wood samples were treated with hot and cold soaking. The duration of hot soaking were 3, 5, and 7 hours, while for cold soaking were 3, 5, and 7 days. The result showed that the highest retention of extract was achieved by cold soaking for 7 days at 9.4 kg m-3, and the lowest retention was achieved by hot soaking for 3 hours at 1.9 kg m‑3. The highest penetration occured by cold soaking for 7 days at 8.08 mm and the lowest was that with hot soaking for 3 hours at 2.81 mm. However, the distribution of the extract in the agathis wood structures could not be detected by stereo microscope. In the the case of the candlenut wood, the extract was distributed in the parenchyma cell.

Sifat-Sifat Arang Aktif Kulit Batang Sagu Hasil Karbonisasi Hidrotermal

Kulit batang sagu merupakan salah satu limbah padat pengolahan tepung sagu (Metroxylon sp) yang berpotensi digunakan sebagai bahan baku arang aktif. Tujuan penelitian ini untuk mengetahui sifat-sifat arang aktif kulit batang sagu yang dibuat melalui metode karbonisasi hidrotermal dan aktivasi steam. Pembuatan arang aktif didahului dengan pembuatan prekursor (bahan awal pembuatan arang aktif) melalui metode hidrotermal pada suhu 250 °C dan dilanjutkan dengan aktivasi pada suhu 800 °C selama 0, 60, 80, dan 100 menit. Pengujian proximat dan daya jerap iodin menggunakan standar SNI dan pengamatan struktur arang aktif menggunakan X-ray diffraction (XRD). Hasil penelitian menunjukkan bahwa rendemen 45,90-55,70%, kadar air 5,82-7,06%, zat terbang 5,66-9,40%, kadar abu 12,24-14,54%, karbon terikat 78,36-79,80%, daya jerap iodin 455,59-759,86 mg.g-1, dan derajat kristalinitas 31,66-38,81%. Arang aktif terbaik adalah arang aktif kulit sagu perlakuan steaming 80 menit yang memiliki daya jerap iodin sesuai dengan SNI 06-3730-1995 yaitu ≥750 mg.g-1.

Prediksi Nilai Kuat Lentur Kayu Tropis Berdasarkan Nilai Modulus Elastis

Dalam SNI 7973:2013, nilai modulus elastisitas statik kayu (MoEs) digunakan sebagai dasar pengelompokan mutu kayu. Nilai MoEs juga dapat digunakan untuk memprediksi sifat mekanika kayu yang lain. Penelitian ini melakukan kajian untuk mendapatkan persamaan yang dapat digunakan untuk memprediksi nilai berdasarkan nilai rata rata modulus elastisitas dan persamaan untuk mendapatkan nilai kekuatan lentur (MoR) berdasarkan nilai MoEsnya dari kayu tropis yang ada di Indonesia. Uji lentur statik dilakukan berdasarkan EN 408, sementara itu uji lentur dinamik dilakukan menggunakan metode stress wave velocity. Selain itu, data sekunder hasil pengujian lentur dari para peneliti terdahulu juga digunakan dalam penelitian ini. Dari hasil analisis, nilai adalah sebesar 0,754 dari . Analisis regresi linear menunjukkan bahwa nilai MoR dapat didekati dengan persamaan 𝑀𝑜𝑅 = −1,359 + 0,0061, dimana dari persamaan ini dapat diketahui bahwa nilai desain acuan yang ada pada Tabel 4.2.1 SNI 7973:2013 cenderung memberikan faktor keamanan yang memadai. Pengujian lentur dinamik kayu menunjukkan bahwa hubungan antara modulus elastisitas dinamik (MoEd) dan MoEsdapat didekati melalui persamaan = −1330,1 + 1,254 dengan koefisien determinasi () sebesar 0,69.