Pengaruh Modifikasi Steam dan Pembilasan NaOH terhadap Keasaman Enam Jenis Bambu

2021 ◽  
Vol 18 (1) ◽  
pp. 11-18
Author(s):  
Muhammad I. Maulana ◽  
Marwanto Marwanto ◽  
Sena Maulana ◽  
Aginsa T. Putri ◽  
Nicken O Putri ◽  
...  

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%.

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 975
Author(s):  
Antonio Copak ◽  
Vlatka Jirouš-Rajković ◽  
Nikola Španić ◽  
Josip Miklečić

Oriented strand board (OSB) is a commonly used structural wood-based panel for walls and roof siding, but recently the industry has become interested in OSB as a substrate for indoor and outdoor furniture. Particleboard is mainly used in furniture productions and has become popular as a construction material due to its numerous usage possibilities and inexpensive cost. Moisture is one of the most important factors affecting wood-based panel performance and the post-treatment conditions affected their affinity to water. When OSB and particleboard are used as substrates for coatings, their surface characteristics play an important role in determining the quality of the final product. Furthermore, roughness can significantly affect the interfacial phenomena such as adsorption, wetting, and adhesion which may have an impact on the coating performance. In this research particleboard and OSB panels were sanded, re-pressed and IR heated and the influence of surface treatments on hardness, roughness, wetting, water, and water vapour absorption was studied. Results showed that sanding improved the wetting of particleboard and OSB with water. Moreover, studied surface treatments increased water absorption and water penetration depth of OSB panels, and re-pressing had a positive effect on reducing the water vapour absorption of particleboard and OSB panels.


2021 ◽  
pp. 1358863X2098760
Author(s):  
Elizabeth C Lefferts ◽  
Alexander J Rosenberg ◽  
Georgios Grigoriadis ◽  
Sang Ouk Wee ◽  
Stephen Kerber ◽  
...  

Firefighting is associated with an increased risk for a cardiovascular (CV) event, likely due to increased CV strain. The increase in CV strain during firefighting can be attributed to the interaction of several factors such as the strenuous physical demand, sympathetic nervous system activation, increased thermal burden, and the environmental exposure to smoke pollutants. Characterizing the impact of varying thermal burden and pollutant exposure on hemodynamics may help understand the CV burden experienced during firefighting. The purpose of this study was to examine the hemodynamic response of firefighters to training environments created by pallets and straw; oriented strand board (OSB); or simulated fire/smoke (fog). Twenty-three firefighters had brachial blood pressure measured and central blood pressure and hemodynamics estimated from the pressure waveform at baseline, and immediately and 30 minutes after each scenario. The training environment did not influence the hemodynamic response over time (interaction, p > 0.05); however, OSB scenarios resulted in higher pulse wave velocity and blood pressure (environment, p < 0.05). In conclusion, conducting OSB training scenarios appears to create the largest arterial burden in firefighters compared to other scenarios in this study. Environmental thermal burden in combination with the strenuous exercise, and psychological and environmental stress placed on firefighters should be considered when designing fire training scenarios and evaluating CV risk.


2020 ◽  
Vol 70 (3) ◽  
pp. 283-292
Author(s):  
Daniel Way ◽  
Frederick A. Kamke ◽  
Arijit Sinha

Abstract Development of moisture gradients within wood and wood-based composites can result in irreversible moisture-induced damage. Accelerated weathering (AW), generally employing harsh environmental conditions, is a common tool for assessing moisture durability of wood composite products. Use of milder AW conditions, such as cyclic changes in relative humidity (RH), may be of interest to the wood-based composites industry in assessing moisture durability under more realistic conditions. The primary objective of this study was to determine whether moisture profile development in oriented strand board and plywood during cyclic RH changes could be reasonably predicted with a simple moisture transport model, which may be practical for wood-based composite industry members seeking to develop new AW protocols. The diffusion model based on Fick's second law with empirically determined moisture transport parameters fits the experimental data reasonably well for the purpose of screening RH parameters.


Holzforschung ◽  
2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Cheng Zhou ◽  
Gregory D. Smith ◽  
Chunping Dai

Abstract Wood-based composites, such as oriented strand board, are typically manufactured by consolidating mats of resinated wood elements under heat and pressure. During this process, the temperature and moisture content distributions within the mat greatly affect the properties of end products. To improve the fundamental understanding of mat consolidation during hot-pressing, a model is established to investigate the transverse compression behavior of aspen wood strands for a variety of combinations of temperatures (20–200°C) and moisture contents (0–15%). A regression approach is used to obtain the modulus-temperature-moisture relationship. In addition, elevated temperatures and moistures are found to influence the strain function of wood strands, which was previously assumed to be independent of these factors.


2006 ◽  
pp. 257-266
Author(s):  
Mladjan Popovic ◽  
Milanka Djiporovic-Momcilovic ◽  
Jovan Miljkovic ◽  
Ivana Gavrilovic-Grmusa

This work presents the method for improvement of direct screw connection performance in conventional particleboard (PB) and oriented strand board (OSB). It is conceived on adhesive insertion into the pilot hole prior to embedment of the screw. The tests were carried out on the PB and OSB, both presenting interior boards and with the same nominal thickness of 18 mm. Particleboard screws of the 5 mm in diameter were inserted in the edge of the board. Pilot hole diameters were 2,5 mm and 3,0 mm and the depth of embedment was 30 mm for all tests. The chosen PVAc adhesive (type 3) with the addition of wood flour as consolidator in the range from 3-10% was inserted into pilot-hole. Tests were also obtained after consequent reassembly of the screw connection in order to examine the ratio of loss in withdrawal forces in such case. It was found that the insertion of PVAc adhesive into the pilot hole and the addition of wood flour have the positive effects on the screw withdrawal force in the tested boards.


2007 ◽  
pp. 109-117
Author(s):  
Jovan Miljkovic ◽  
Mladjan Popovic ◽  
Milanka Djiporovic-Momcilovic ◽  
Ivana Gavrilovic-Grmusa

This research was based on presumption that the changes in size and shape of wood particles are expected to have certain impact on the particleboard quality in general. Since the conventional particleboard (PB) and oriented strand board (OSB) were built of the quite diverse wood particles, they present interesting specimens in the comparison tests. In this work, the influence of the wood particles type on the edge screw holding performance of conventional particleboard and OSB was investigated. Those tests were obtained with the screw diameters of 4.0 mm, 4.5 mm and 5 mm. Depth of embedment was 30 mm for all tests and with the pilot-hole diameter kept in the range of 80-90% in respect of the screw root diameter. Additional tests of the thickness density profile and tensile strength perpendicular to the surface of the board were conducted. Since the middle layer structure of the particleboard embeds the screw body, both mentioned parameters are considered important in the aspect of the quality of the edge screw holding performance. In order to have further insight into the conformation of the middle layer the image survey was obtained on the split board section presenting the surface of the middle layer. Significant differences in the SWR performance of OSB and PB was recorded at all screw diameters. For the screw withdrawal tests parameters OSB samples showed 56-73% superior mean values then conventional PB. On the other hand, the OSB showed wider dispersions of measured withdrawal forces at all screw diameters, which might present some of the problems in certain engineering and project calculations.


2021 ◽  
Vol 71 (3) ◽  
pp. 199-208
Author(s):  
Qingzheng Cheng ◽  
Juliet D. Tang ◽  
Chengfeng Zhou ◽  
Wei Jiang ◽  
Lixia Hu ◽  
...  

Abstract Soy flour was evaluated as a partial substitute for resin in the manufacture of oriented strand board (OSB), a wood-based composite that often replaces solid lumber and plywood in structural applications in the construction industry. Since the presence of soy could alter OSB biodegradation properties, termite resistance of OSB panels made with 0, 10, and 20 percent of polymeric methylene diphenyl diisocyanate (pMDI) resin substituted with soy flour (OSB0, OSB10, and OSB20, respectively) was investigated. Single choice tests between three types of OSB and southern yellow pine (SYP) solid wood and an OSB choice test (OSB0 vs. OSB10) were evaluated. Results indicated that termites always showed a preference for SYP, with the OSB becoming less palatable when soy flour was present. Percentage weight losses for OSB0, OSB10, and OSB20 were 5.7×, 8.4×, and 8.6× less, respectively, compared with SYP. In the absence of SYP, termites did not differentiate OSB0 from OSB10, with OSB10 showing 1.5× less weight loss compared with OSB0. Visual rating data supported weight loss data, except significantly less damage was only found when the choice paired SYP with OSB made with soy (OSB10 or OSB20). Termite consumption preference for SYP was explained by differences in water absorption kinetics. SYP reached saturation (105% moisture content) within 1 week on moist sand, while moisture content of OSB composites slowly climbed to 79 percent over 4 weeks, never reaching a plateau. Lower moisture content was due to the presence of water-repellent resin and wax in the OSB.


2006 ◽  
Vol 45 (6) ◽  
pp. 1974-1988 ◽  
Author(s):  
Clement W. B. Lee ◽  
Hector M. Budman ◽  
Mark D. Pritzker

2021 ◽  
pp. 073490412110366
Author(s):  
Junhui Gong ◽  
Hongen Zhou ◽  
Hong Zhu ◽  
Conor G McCoy ◽  
Stanislav I Stoliarov

Oriented strand board is a widely used construction material responsible for a substantial portion of the fire load of many buildings. To accurately model oriented strand board fire response, kinetics and thermodynamics of its thermal decomposition and combustion were carefully characterized using milligram-scale testing in part I of this study. In the current work, Controlled Atmosphere Pyrolysis Apparatus II tests were performed on representative gram-sized oriented strand board samples at a range of radiant heat fluxes. An automated inverse analysis of the sample temperature data obtained in these tests was employed to determine the thermal conductivities of the undecomposed oriented strand board and condensed-phase products of its decomposition. A complete pyrolysis model was formulated for this material and used to predict the mass loss rates measured in the Controlled Atmosphere Pyrolysis Apparatus II experiments. These mass loss rate profiles were predicted well with the exception of the second mass loss rate peak observed at 65 kW m−2 of radiant heat flux, which was underpredicted. To further validate the model, cone calorimeter tests were performed on oriented strand board at 25 and 50 kW m−2 of radiant heat flux. The results of these tests, including both mass loss rate and heat release rate profiles, were predicted reasonably well by the model.


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