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Selected properties of medium density fiberboard (MDF) panels made from bamboo and rice straw
Abstract
This study evaluated some of the important properties of medium density fiberboard (MDF) panels made from bamboo (Dendrocalamus asper) and rice straw. A total of 20 experimental panels with an average target density of 0.70 g/cm 3 were made from 100 percent bamboo, 100 percent rice straw and the mixture of 80 to 20 percent and 50 to 50 percent ratios of bamboo and rice straw fiber. Modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength, thickness swelling, density profiles, and surface roughness of the specimens were determined. Samples with 0.75 g/cm 3 density had 34 percent and 27 percent higher MOE and MOR values than those of samples with target density of 0.65 g/cm 3, respectively. It appears that using 5 percent of rice straw in the panels did not significantly reduce both physical and mechanical properties of the samples. Measurement of surface characteristics of the samples resulted that such panels can be used as substrate for thin overlays without any significant problems. Initial findings of this study suggest that both nonwood underutilized species can be considered as raw material to manufacture value-added MDF panels.
... The MDF panel is uniform, smooth, and free from knots and has good properties with equally distributed strength, which makes it an excellent substitute for solid wood in interior and exterior applications including packaging, furniture and cabinets, wall paneling, molding and door parts ). In addition to virgin wood fibers, there are several lignocellulosic materials that are available as raw fibers for the fabrication of MDF, such as bagasse (Hse et al. 2006), canola straw (Yousefi 2009), rice straw (Hiziroglu et al. 2007), rice husk (Vargas et al. 2014), wheat straw (Halvarsson et al. 2008), corn biomass (Theng et al. 2015), oil palm trunk (Ibrahim et al. 2013), and bamboo (Hiziroglu et al. 2008). Among them, bamboo is considered as a good source of MDF fibers due to its different qualities such as high strength, straightness, lightness combined with extraordinary hardness, easy propagation and short rotation (Li 2004). ...
... Many researchers manufactured bamboo-based composite panels including OSB panels (Maulana et al. 2017, Li et al. 2018, particleboards (Yang et al. 2014, Umemura et al. 2015, and fiberboards (Hiziroglu et al. 2007, Sihag et al. 2017b. Moisture gradient is the factor that affects the physical and mechanical properties of the wood and wood composites. ...
In this study, Medium Density Fiberboard (MDF) was manufactured from bamboo (Dendrocalamus strictus Roxb. Nees) fibers and phenol-formaldehyde (PF) resins at different hot-pressing pressures using a novel needle-punching treatment to improve the properties of the panel. One-, two-, three- and four-time needle-punching treatments (1TP, 2TP, 3TP, and 4TP) were used in this work. Laboratory MDF panels were prepared by mixing bamboo fibers with 10% of PF resins. The needle-punching treatments were applied simultaneously on resinated bamboo fibers during the mat formation. The MDF mats were then hot-pressed at 14.0, 17.5, 21.0 kg/cm² and at 150 °C for 15 min. Thereafter, the physical and mechanical properties of MDF panels were evaluated as per Indian Standard (IS) specification IS: 12406. It was observed that the combination of novel needle-punching technique and hot-pressing pressure enhanced the physical and mechanical properties of MDF panels. Statistical analysis suggested that a combination of 3TP and 21.0 kg/cm² of pressures produced the MDF panel with satisfactory results. The research indicated that a combination of needle-punching treatment and hot-pressing pressure could be an excellent technique to improve the properties of the MDF panel.
... Globally, many lignocellulosic material options exist for the production of composite products, both in industrialised as well as in developing countries. Tested in production of particle-and fibreboards were for example wheat straw (Han et al. 2001, Mo et al. 2003, Boquillon et al. 2004, Schirp et al. 2006a, paddy straw (Sampathrajan et al. 1992, Hiziroglu et al. 2007, reed (Han et al. 2001, Habibi 2006, Miscanthus fibres (Velasquez et al. 2002, Salvadó et al. 2003, Agropyron straw (Zheng et al. 2007), bamboo (Zhang et al. 1996, Chen et al. 1998, Ma et al. 1998, Bai et al. 1999, Nugroho & Ando 2000, Sumardi et al. 2006, Hiziroglu et al. 2007, hemp fibres (Boquillon 2006, own research), flax (Papadopoulos & Hague Fig. 19 Pilot plant for particle board production in the "Biotechnikum" at the Institute of Forest Botany in Göttingen. Top: two bunkers in line allow the production of threelayered boards. ...
... Globally, many lignocellulosic material options exist for the production of composite products, both in industrialised as well as in developing countries. Tested in production of particle-and fibreboards were for example wheat straw (Han et al. 2001, Mo et al. 2003, Boquillon et al. 2004, Schirp et al. 2006a, paddy straw (Sampathrajan et al. 1992, Hiziroglu et al. 2007, reed (Han et al. 2001, Habibi 2006, Miscanthus fibres (Velasquez et al. 2002, Salvadó et al. 2003, Agropyron straw (Zheng et al. 2007), bamboo (Zhang et al. 1996, Chen et al. 1998, Ma et al. 1998, Bai et al. 1999, Nugroho & Ando 2000, Sumardi et al. 2006, Hiziroglu et al. 2007, hemp fibres (Boquillon 2006, own research), flax (Papadopoulos & Hague Fig. 19 Pilot plant for particle board production in the "Biotechnikum" at the Institute of Forest Botany in Göttingen. Top: two bunkers in line allow the production of threelayered boards. ...
... To achieve lower energy consumption and coal emission, researchers have been searching for alternative materials for traditional adhesives. Many studies have reported straw resin boards along with their issues, such as low cohesion, thickness expansion and geometric instability [85][86][87]. Resin is not an ideal available binder due to its high energy consumption and cost. In China, the price of cement is 400-500 ¥/ton, while that of urea-formaldehyde resin is 2000-4000 ¥/ton. ...
To develop green thermal insulation materials made of straw to replace high energy consumption and high pollution materials, such as asbestos and polystyrene, this paper reviews the relevant characteristics of straw as a thermal insulation filler and the research progress of mechanical straw building materials (i.e., the straw filler is placed in the interlayer and fasted by friction or gravity). Research studies on straw combustion, moisture absorption, and heat transfer mechanisms are reviewed. Additionally, the research status of three kinds of mechanical straw building materials, namely straw bales/laminated wallboards, beetle elytron plate walls, and mixed straw fillers, is also explained. This assessment shows that straw thermal insulation fillers have good fire safety and thermal insulation performance. The straw bale/laminated wallboard system is mature, with rich varieties and practical applications, while beetle elytron plate walls and mixed straw fillers are still in the development stage. Although there are many related research results, more reports on the heat transfer mechanism, material selection, and application forms are needed, which is an important direction for future systematic research. Actively promoting the application of green mechanical straw-filled sandwich structures in more fields will produce good social and economic benefits.
... m 3 (BPS, 2017). The strength of this product lied in its use of varied raw materials and industrial wastes (Hiziroglu et al., 2007;Garcia et al., 2018). In its production process, some MDF types were laminated with melamine, polyvinyl chloride, veneer and other materials to improve the surface appearance and other physical, mechanical qualities (Kılıç et al., 2009;Jocham et al., 2011;Taghiyari and Norton, 2014). ...
... However, the characteristics of rice straw tend to lead to low-quality boards. Rice straw is not wetted or penetrated well by hydrophilic urea formaldehyde (UF) resin or phenol formaldehyde (PF) resin, due to its inorganic silica content and wax-like substances covering the surface [1][2][3]. Several pretreatments have been examined to improve these compatibility issues between rice straw and resins. One was a mechanical method to break down the wax-layer, which improved the diffusion and penetration of resins into the straw fibers and increased the internal bonding of rice straw fiberboards [4]. ...
Rice straw is a troublesome biomass for an industrial application because of its high silica content and the wax-like substances covering the surface. At manufacturing binderless boards, which are considered environmentally friendly as they do not contain synthetic resins, rice straw silica contributed to water resistance, while the wax-like substances adversely affected self-bonding. This study investigated the effects of steam treatment on the self-bonding of binderless boards manufactured from rice straw. The chemical changes during steam treatment were examined by gas chromatography–mass spectrometry (GC–MS), and their influence on the bonding properties is discussed. Internal bonding strength and water resistance significantly increased by steam treatment. They also increased with increasing pressing temperature, and decreasing particle size. GC/MS analysis showed that not only hemicellulose and lignin, but also amorphous cellulose was decomposed during the steam treatment. Among the degradation products, 5-hydroxymethylfurfural was suggested to contribute to self-bonding during hot-pressing, while furfural was vaporized from the rice straw. Fine-grinding to below 150 μm after steam treatment resulted in high water resistance and an internal bonding strength of 0.6 MPa, which met the Japan Industrial Standards (JIS) requirement for Type-30 medium-density fiberboard (MDF). This mild pretreatment offers an alternative to steam explosion.
... Oleh karena itu, perlu dilakukan penelitian tentang pemanfaatan pelepah sagu sebagai bahan baku papan komposit dengan melakukan diversifikasi produk pelepah sagu melalui modifikasi pelepah sagu menjadi bahan baku papan komposit untuk dinding maupun atap bangunan seperti produk komposit lainnya, produk ini diharapkan dapat digunakan pada bangunan-bangunan tradisional. Baru-baru ini telah banyak dilakukan penelitian tentang pengembangan pembuatan papan komposit dari bahan baku yang dapat diperbaharui selain kayu (Chew et al. 1994, Chow et al. 1993, Chen & Hua 1991, Hiziroglu et al. 2007, Gopar & Sudiyani 2004. Penelitian ini bertujuan untuk optimalisasi pemanfaatan pelepah sagu sebagai bahan baku papan komposit dengan menentukan jenis perekat dan kadar perekat optimum dalam pembuatan papan komposit. ...
Plantation waste has gained increasing attention as an alternative raw material for use in the manufacture of composite boards, i.e. waste of sago plantation. Medium density composite boards were made from zephyr of sago midrib to evaluate the effects of resin and adhesive content levels. The boards were fabricated using polyurethane (PU) and phenol formaldehyde (PF) resin with three levels of adhesive content i.e. 10%, 12%, and 14%. Physical (moisture content, density, water absorption, and thickness swelling) and
mechanical (Modulus of Rupture, Modulus of Elastisity, Screw Holding, and Internal
Bonding) properties of composite board were evaluated according to JIS A 5908-2003
standard. Research result showed that properties of composite board made from sago frond with 14% content level of polyurethane adhesive better than other composite board. Based on composite board properties, the board was suitable as building raw material and furniture i.e. partition, cupboard, table, and roof
... Several trials were done to produce bamboo particle board and medium-density fibreboard (MDF; Hiziroglu et al., 2007;Lee et al., 2006;Li et al., 2004;Sumardi et al., 2007). The use of bamboo as a (partial) wood substitute for manufacturing MDF panel production gives good perspectives. ...
Whilst the majority of bio-based building focuses on wood, the use of nonwood materials
in the built environment is an area of growing importance.
This chapter focus on the background and importance of nonwood bio-based
building materials in the construction market and will review the properties, present
and historic use, and the state-of-the-art research of the most relevant or innovative
raw materials, in particular, flax, hemp, straw, bamboo and rattan, reed, wool, peat,
grass and several pith plants.
... Grâce à sa croissance rapide, les tiges de bambou peuvent être exploitées à partir de la troisième année (ALIPON et al., 2009), alors qu'il faut attendre au minimum 20 ans, voire plus de 80 ans, pour les bois de forêt naturelle comme Dalbergia sp. Du point de vue technologique, les études des propriétés technologiques du bambou dans d'autres pays ont montré que certaines espèces ont des propriétés physiques et mécaniques meilleures que le bois (HIZIROGLU, 2007 ;LEE et al., 1996) et que la fibre de bambou se trouve parmi les plus performantes, avec les fibres de carbone et de verre (YU et al., 2007). ...
Bamboo is of considerable importance for many households in Madagascar, both rural and urban. Bamboo is mainly grown in Madagascar's central uplands and eastern humid forests. Based on bibliographic research, field interviews and laboratory analyses, this study established internal and external diagnoses of the bamboo sector in Madagascar's eastern regions, particularly the Analanjirofo and Antsinanana districts. These diagnoses were then used to formulate strategic options. Several strategic options were noted, especially the support provided by a specialised organisation (INBAR), favourable conditions for extension work and a high level of motivation among those concerned, all of which allow predict a strong development of the Bamboo chain in the future. Furthermore, the physical and mechanical properties of bamboo species found in the study zone are of considerable interest to meet needs for various kinds of uses. The constraints noted include inadequate regulatory measures, archaic processing techniques and a low rate of recovery of byproducts. The ignorance of the exact potential of the area available as well as the properties of the thatches limits the valorization of bamboo. The revival of the Bamboo chain could partly contribute to the long-term preservation of other natural forest resources. This study demonstrates the importance of bamboo in eastern Madagascar and has established a basis for more in-depth investigations.
... On the other hand, further studies are needed to verify if the high silica content on the modified fibers causes excessive tool wear during processing. For example, Researchers reported concerns on this matter for application of bamboo as composite lumber (Malanit et al., 2007), black locus wood species for particleboard production (Nemli et al., 2004), and rice and bamboo for MDF production (Hiziroglu et al., 2007). ...
One of the drawbacks in the use of cellulose fibers in fiber-cement products is their high water absorption, which leads to fiber mineralization in the Portland cement matrix. Thus, this study aimed to evaluate different reaction conditions for deposition of the SiO2 nanoparticles on the surface of cellulose pulp fibers, and their influence on the moisture adsorption of the hybrid organic-inorganic material formed. SiO2 nanoparticle deposition was done with the sol-gel process, testing four reaction times (2, 12, 18 and 24 h) and three contents (1.00, 2.25 and 4.50 mL) of the tetraethyl orthosilicate (TEOS) precursor. The modification time and TEOS precursor content directly influence the amount of Si deposited on the fiber surface, the nanoparticle diameter distribution, and the resistance to moisture adsorption. The moisture adsorption capacity of the modified cellulose fibers was reduced up to 50%. These results are interesting for ongoing research in the direction of fiber modification strategies for application of the cellulose fibers as durable reinforcement in cement based composites.
... On the other hand, further studies are needed to verify if the high silica content on the modified fibers causes excessive tool wear during processing. For example, Researchers reported concerns on this matter for application of bamboo as composite lumber (Malanit et al., 2007), black locus wood species for particleboard production (Nemli et al., 2004), and rice and bamboo for MDF production (Hiziroglu et al., 2007). ...
One of the drawbacks in the use of cellulose fibers in fiber-cement products is their high water absorption, which leads to fiber mineralization in the Portland cement matrix. Thus, this study aimed to evaluate different reaction conditions for deposition of the SiO2 nanoparticles on the surface of cellulose pulp fibers, and their influence on the moisture adsorption of the hybrid organic-inorganic material formed. SiO2 nanoparticle deposition was done with the sol-gel process, testing four reaction times (2, 12, 18 and 24 h) and three contents (1.00, 2.25 and 4.50 mL) of the tetraethyl orthosilicate (TEOS) precursor. The modification time and TEOS precursor content directly influence the amount of Si deposited on the fiber surface, the nanoparticle diameter distribution, and the resistance to moisture adsorption. The moisture adsorption capacity of the modified cellulose fibers was reduced up to 50%. These results are interesting for ongoing research in the direction of fiber modification strategies for application of the cellulose fibers as durable reinforcement in cement based composites.
... On the other hand, further studies are needed to verify if the high silica content on the modified fibers causes excessive tool wear during processing. For example, researchers reported concerns on this matter for application of bamboo as composite lumber (Malanit, Barbu & Früwald, 2007), black locus wood species for particleboard production (Nemli et al., 2004), and rice and bamboo for MDF production (Hiziroglu, Bauchongkol, Fueangvivat, Soontonbura, & Jarusombuti, 2007). Fig. 2 shows semi-quantitative data (from EDS measurements) of the Si content (by mass) deposited on the cellulose fibers under different reaction conditions. ...
This study aimed to evaluate reaction conditions for deposition of SiO 2 nanoparticles on the surface of cellulose fibers and their influence on moisture adsorption of the hybrid organic–inorganic material formed. SiO 2 nanoparticle deposition was carried out with the sol–gel process testing four reaction times (2, 12, 18, and 24 h) and three contents of the tetraethyl-orthosilicate (TEOS) precursor (1.9, 4.2 and 8.4 g g −1 of cellulose fiber). Modification time and TEOS content directly influence the amount of Si deposited on the fiber surface, nanoparticle diameter distribution, thermal stability, and resistance to moisture adsorption. There is a tendency of slight increase of nanoparticle size and the amount of Si deposited with increasing reaction time. SiO 2 nanoparticles were bonded on the surface of the cellulose fibers and are able to improve thermal stability of the material, increasing onset degradation temperature. The moisture adsorption capacity of the modified cellulose fiber was reduced up to 50%.
... Grâce à sa croissance rapide, les tiges de bambou peuvent être exploitées à partir de la troisième année (ALIPON et al., 2009), alors qu'il faut attendre au minimum 20 ans, voire plus de 80 ans, pour les bois de forêt naturelle comme Dalbergia sp. Du point de vue technologique , les études des propriétés technologiques du bambou dans d'autres pays ont montré que certaines espèces ont des propriétés physiques et mécaniques meilleures que le bois (HIZIROGLU, 2007 ; LEE et al., 1996) et que la fibre de bambou se trouve parmi les plus performantes, avec les fibres de carbone et de verre (YU et al., 2007). Malgré cela, on dispose aujourd'hui de peu d'informations sur le fonctionnement de la filière et sur les propriétés technologiques des bambous à Madagascar. ...
Les bambous occupent une place importante dans la vie de nombreux ménages tant ruraux qu'urbains à Madagascar. Ils sont distribués essentiellement le long des massifs centraux de l'île et dans la forêt humide de l'Est. À partir d'un travail bibliographique, d'entretiens sur le terrain et de travaux de laboratoire, cette étude établit un diagnostic interne et externe de la filière bambou dans les zones orientales de Madagascar, particulièrement les régions Analanjirofo et Atsinanana. Suite à ces diagnostics, des options stratégiques ont été formulées. Plusieurs points forts ont été notés, notamment l'appui d'un organisme spécialisé (Inbar), l'existence de conditions d'extension favorables et la motivation des acteurs qui permettent de présager un fort développement de cette filière dans le futur. De plus, les espèces rencontrées dans la zone possèdent des propriétés physico-mécaniques intéressantes, permettant de satisfaire les besoins pour diverses catégories d'utilisations. Comme contraintes, on peut noter la défaillance des mesures réglementaires, les techniques de transformation archaïques et la faible récupération des sous-produits. La méconnaissance des potentialités exactes, aussi bien en termes de superficie disponible qu'en ce qui concerne les propriétés des chaumes, limite la valorisation du bambou. La relance de la filière bambou garantira en partie la pérennisation d'autres ressources des forêts naturelles. Cette étude a permis de démontrer l'importance des bambous dans les zones orientales de Madagascar. Elle constitue un point de départ pour une investigation plus approfondie.
... In order to solve these problems, an appropriate combination of water-based adhesives with MDI resin, or an appropriate mixture of straw particles with low quality woody materials like wood, bamboo and other biomass residues [22][23][24], has been applied to improve bending strength, water resistance, and internal bond strength. However, with the decreases in forest resources, shortage of wood and increasing price of wood, there is a need to find alternative sources of woody materials for mixing with straw particles to produce high performance particleboard. ...
Novel lignocellulosic hybrid particleboard composites with low cost and high performance using the mixture of rice straws and coir fibers were developed in this work. NaOH (sodium hydroxide) aqueous solution was used to remove the wax and silica layer of rice straw surface. The effects of rice straws/coir fibers (R/C) mass ratios on the physical (thickness swelling) and mechanical (modulus of rupture, modulus of elasticity and internal bond strength) properties of particleboard composites were investigated. The results show that NaOH treatment was an effective method for improving wettability of rice straw surface with smaller contact angles and larger diffusivity–permeability constant. The SEM (scanning electron microscope) observation also gave some evidences such as more rough surface and less number of silica cells after NaOH treatment for improving wettability of rice straw surface. The coir fibers content had a significant negative linear effect on the bending properties and thickness swelling, but a significant positive linear effect on the internal bonding strength due to the lower wax and holocellulose content of coir fiber. When no diisocyanate resin applied, the particleboard composites made with only phenol formaldehyde resin at the optimal R/C ratio satisfied the requirements for load-bearing boards used in dry conditions based on Chinese Standard, indicated that the mixture of rice straws and coir fibers to make high quality particleboard composites was a cost-effective and environment friendly approach.
... Since bamboo itself has 1250 species, hence each bamboo fibres used in manufacturing MDF is expected not the same. Until now, researchers still in the middle of trying new species of bamboo for examples bamboo Phyllostachys pubescens2425 and Dendrocalamus asper [26] in producing MDF. ...
Bamboo or Bambusa in botanical has 7-10 subfamilies of genres and there are 1575 difference species ranging from the type of wood to bamboo herb. However, each particular species of bamboo has different properties and qualities [1]. Bamboo is easily accessible globally, 64% of bamboo plantation, as can be seen in Figure 1, originated from Southeast Asia, 33% grown in South America, and the rest comes from Africa and Oceania [2]. Bamboo productions dated back to thousands of years ago and thus they are rich with traditional elements. Bamboo naturally, suitable for varieties of uses and benefits. Bamboo often used as materials for constructions or used as the raw materials for the production of paper sheet, they are also used to control erosion and also for embellishments. Therefore, bamboo plant is sometimes regarded by some people as having positive features towards life such as properity, peace and mercy [3]. Recently, issues relating to environmental threatened the life cycle of the environment globally due to the countries using various types of materials that are not biodegradable by industrial sectors globally. It has becoming a serious matter since it is closely related to the Product Lifecycle Phase resulted from extraction or deposition of waste materials that are not disposed properly [4-5]. Increment of logging activities for variety of purposes has resulted to the failing of absorbtion of carbon dioxide emission by the forest of which large amount of CO₂ are released into the atmosphere trapping the heat withing the atmosphere (green house effect) and causing the global warming.
... Many properties of particleboard are investigated in numerous past studies but no research has attempted to evaluate adhesion strength of commercially produced coated MDF panels in Turkey [3][4][5]. Currently there are no acceptable standards and methods to evaluate the surface quality of wood composites. One of the main advantages of the stylus method which has been employed in this work is to have an actual profile of the surface and standard numerical roughness parameters which can be calculated from the profile [6]. ...
The objective of this study is to evaluate surface roughness and adhesion strength of commercially manufactured medium density fiberboard (MDF) panels as function of relative humidity exposure levels. Surface roughness of the samples conditioned at 65%, 75% and 85% relative humidity was measured using a surface profiler. Adhesion strength of the samples coated with polyurethane finish was also determined by employing pull-off type test set up. Roughness values of the panels increased as they are exposed to higher relative humidity levels ranging from 65% to 85%. The highest adhesion strength value was found as 2.20 N/mm2 for the samples made from unrefined fibers exposed to 65% relative humidity. Majority of the failures took place within adhesion line between coating and the substrate with a very limited torn fibers. Overall adhesion strength characteristics of the samples adversely influenced by increased value of relative humidity exposure.
... Wax has been used as a traditional water retardant for dimensional stability of wood and straw panels ( Pan et al. 2006;Hiziroglu et al. 2007;Xu et al. 2009). Two types of wax are utilized in processing of panels, i.e., molten and emulsified wax. ...
Rice straw fiberboard was made using 12 wt % urea-formaldehyde (UF) resin as binder and 1.0 wt % polymeric methylene diphenyl diisocyanate (pMDI) and 1.2 wt % wax emulsion as water retardants. The prepared fiberboards were heat-treated at 120, 150, 185, and 210°C in the presence of steam in a high-temperature dry kiln, respectively for 90 min. The effect of water retardants and heat treatment on the water resistant and some mechanical properties of the fiberboards were investigated. It was found that the water resistance of the rice straw fiberboard could not be improved by adding wax emulsion. The use of pMDI to the system significantly increased the interfacial strength and reduced 24-h thickness swelling (TS) compared to the boards with or without wax emulsion. After heat treatment, the TS was significantly decreased due to the decrease in the free reactive hydroxyl group content of rice straw fiber. Some mechanical properties of the fiberboards, such as the internal bonding strength, modulus of elasticity, and modulus of rapture were dramatically reduced with increasing temperature from 120°C to 210°C.
Objective:
To morphologically analyze, by means of scanning electron microscopy (SEM), agglomerated boards made from rice husk and Hidropul 400, as well as boards made from wood fibers and glue.
Methodology:
For each 7,3 x 3,6 x 1,5 cm test piece, two samples were taken from the external and internal sections of each one of the boards to be analyzed. Thin-layer graphite coatings were made to each one of them, and, by means of SEM, micrographic shots were obtained in the range from 50x to 2000x.
Results:
It was evidenced that the panel made from rice husk had damage to its internal structure due to its porosity, the waxy layers of its coating, the high presence of silica, and the presence of water inside the adhesive, showing irregularities in adhesion between particles and low mechanical properties.
Conclusions:
Although the studied rice husk panel did not achieve the adequate structural properties, it has great applications for interior design. Additionally, due to its porous structure, its potential as a sound-absorbing material is considered. In the same way, the material can be improved by pre-treating the husk or combining it with other, more woody plant fibers such as wood waste, bamboo, coconut fiber, among others.
Aesthetic and strength are not easy to be combined in one wood composite product. This research aimed at combining both utilizing MDF overlaid with avocado, mahogany and pine veneer. Seven types of MDF composite plywood (comply) were designed using two adhesive types of Epoxy and Isocyanat. The adhesive spread weight was 250 g m ⁻² . Cold compression was conducted within 3 hours with the pressure of 15 kg cm ⁻² . The research results showed that flexural modulus (MOE) and flexural strength (MOR) of PMI comply (pine veneer, isocyanat adhesive) increased respectively by 129.5% and 75.9% when compared to MDF. This research recommends that MDF comply may be utilized for the structural and non-structural purposes.
The paper takes into account the most important wood based products used in architecture, structural engineering and design. The amount of roundwood, sawnwood and wood panel production is analysed and forest certification is reported as possible tool to ensure a sustainable forest management, fighting illegal logging and deforestation. A smart review of the most used wood-based products is performed together with the chance to activate a modern short supply chain. The state of art of the wood species actually used is considered together with most important actual challenges addressed to obtain sustainable wood-based products referring to eco-friendly process of gluing and increasing durability. The possibility to use short chain species for structural purposes is reported looking to Italian case studies (chestnut, eucalyptus and pines). A lot of successful prototypes and products have been obtained using short supply species, but research still is needed on the most type or products especially if they are to be used for structural purposes.
The present study was undertaken with the objective to evaluate and compare the physical characteristics, nutritional
quality, antioxidant properties and glycemic index of indigenously grown raw red rice grown in Udham Singh Nagar
district of Uttarakhand and white rice (Sarbati) procured from local market of Uttarakhand, India. Of the thirteen
physical quality parameters evaluated, red rice proved to be superior to white rice in all parameters barring seed
length. Red rice was found to have a higher iron, magnesium, calcium, and zinc content than white rice. Regarding
other nutrients the study revealed that red rice has a higher crude protein (10.49%) and crude fiber (2.71%) content
as compared to white rice. The nutritional quality of red rice was found to be comparable to many millets, fruits and
vegetables. It showed excellent antioxidant properties too such as total phenolic content (143.38 mg GAE/100g of
phenol), total flavonoid content (120.0 mg R.E. /100 gm of flavonoid) and DPPH scavenging activity (25 per cent).
Red rice was found to have a lower glycemic index (63.15 ± 2.63mg/dl) than white rice due to which it can be a part
of the diets of diabetics as well as persons suffering from other non-communicable diseases. Red rice is a storehouse
of nutritional excellence and is a healthier alternative to white or polished rice.
A central composite rotatable orthogonal experimental design of response surface methodology (RSM) was employed to find the optimum technical parameters combination for preparing fiber from rice straw by the straw extruder testbed. Obtainable fiber percentage, the ratio of length to width of the fiber and anti-tensile index were selected as responses, and five factors, such as the length of rice straw, soaking time of straw into water, initial temperature of extruding press, screw rotary speed and feed rate were selected as input variables with five levels respectively. The results indicated that under the condition of an optimum combination that the length of rice straw being 10~14 cm, soaking time being 12~24 h, initial temperature of extruding press being 25°C, screw rotary speed being 70 r/min and feed rate being 60 g/min, the ratio of length to width of the fiber was over 40, anti-tensile index was more than 10 N·m/g and obtainable fiber percentage attained was more than 85%.
When boards were manufactured from rice straw with UF resin, morphological differences, wax and silica adversely affected the boards' properties. The effects of the surface structures such as trichomes and protuberances were examined owing to improve the properties of binderless boards made from rice straw. The effects of silica and wax on the properties of binderless boards were also investigated. Trichomes and protuberances were broken by fine grinding. Wax was removed by extraction with hexane. Silica content was conditioned by fractionation of rice straw. Binderless boards were manufactured by hot-pressing, and their mechanical properties and water resistance were evaluated. Fine grinding increased both the mechanical properties and water resistance of binderless boards. One of the reasons was that size reduction of particles increased the bonding area. Another important reason was that the trichomes and protuberances that inhibit self-bonding were removed by fine grinding. The removal of wax increased self-bonding, and did not decrease the water resistance of boards. De-dusting decreased silica by a small amount, but this did not affect self-bonding. Hence, extraction of hexane and fine grinding were effective in increasing self-bonding of binderless boards made from rice straw. Owing to these pretreatments, the internal bonding and thickness swelling of the binderless boards made from rice straw met the requirements for particleboard and MDF of Japanese Industrial standards (JIS).
A new type of rice seedling carrier named seedling-growing bowl tray made of paddy straw (SGBTMPS) was developed in China. Traditional preparation process for SGBTMPS is complex and difficult to operate. Hence, a new SGBTMPS preparation method has been developed by using straw powder as the main raw material. In this method, modified starch-based adhesive was replaced by the binder of thermosetting adhesive, and preparation constraints such as forming pressure, forming temperature, and dwell time were decreased. The effects of factors such as glue (modified starch-based adhesive), forming pressure, forming temperature and dwell time on SGBTMPS preparation were evaluated by single factor experiment. Orthogonal experiment and comprehensive weight analyses were adopted to optimize the parameters for SGBTMPS preparation. The results showed that optimized parameters were 125% glue and 1.2 kg mixed materials with the forming pressure, temperature, and dwell time of 30 MPa, 140 degrees C and 330 seconds, respectively. Compared with traditional preparation process, the proportioning link, preparation link, and preparation time in the new preparation process were reduced by 66.7%, 33.3%, and 17%, respectively; the pot-hole percentage and the expansion ratio were increased by 0.09% and 0.05%, respectively. This study indicated that the new preparation process for SGBTMPS was simpler and easier to operate and would provide a useful reference for further research and industrialization on SGBTMPS.
Binderless boards were manufactured from rice straw by hot-pressing in order to evaluate the morphological effect of particles from rice straw. For the morphological effect, we examined the influence of particle size and morphological parts of rice straw, respectively. Internal bonding (IB), thickness swelling (TS) and water absorption (WA) were measured as the properties of the boards. As a result, binderless boards were successfully manufactured from rice straw powder smaller than 1 mm. Regarding the effect of morphological part from rice straw, IB of the board made from stem powder was the highest, subsequently followed by leaf blade powder, and leaf sheath powder. IB tended to increase with decreasing ash and silica contents. Trichomes and wart-like protuberances on the epidermis of rice straw might inhibit the bonding between particles. The water resistance of binderless boards made from rice straw was high regardless of low IB. It is possible that wax-like substances on the epidermis of rice straw might contribute to the water resistance of the board.
In this study, surface characteristics of overlaid medium density fiberboard (MDF) panels manufactured from bamboo (Dendrocalamus asper) and rice straw (Oryza sativa) were evaluated. Experimental panels were manufactured from two types of raw materials. Samples with dimensions of 15cm×15cm both types of panels were overlaid with decorative paper with a density of 0.75g/cm3 using urea formaldehyde resin as a binder. Roughness measurements were randomly taken from the surface of overlaid samples using a fine stylus profilometer. Three roughness parameters, average roughness (Ra), mean peak-to-valley height (Rz), and maximum roughness (Rmax) were used to evaluate surface characteristics of overlaid samples conditioned at 55% and 92% relative humidity levels. Statistical analysis revealed that no significant difference was found between roughness values of panels made from two types of raw materials. When the samples were exposed to 92% relative humidity both types of specimens had significantly higher values of Ra, Rz, and Rmax than those of measurements taken at 55% relative humidity. The stylus method is able to detect differences in surface roughness of overlaid panels that can occur due to changes in environmental conditions. Initial findings of this study suggest that both non-wood under-utilized species can be considered as raw material to manufacture value-added MDF panels as substrate for overlaying without having any adverse influence on their surface quality.
This study focused on effects of thermomechanical treatment, acid hydrolysis and enzymatic hydrolysis of rice straw fibre on its water resistant. Xylose and arabinose yields were 19.97% and 2.55%, respectively with thermomechanical treatment, 24.35% and 3.18% with acid hydrolysis, and 20.11% and 2.73% with enzymatic hydrolysis. The acid treatment dissolved hemicellulose significantly, leading to more fines and more voids in the surface of the rice straw fibre. The fines showed a higher water retention value (WRV) of 137.41% and exhibited higher swelling capacity. An increase in acid loading resulted in the increased WRV. The enzymatic hydrolysis increased the crystallinity of cellulose, but no significant correlation could be found between the chemical component and the water resistance of the rice straw fibre.
This study investigated some of the important properties of single-layer particleboard panels made from bamboo (Dendrocalamus asper), rice straw, eucalyptus (Eucalyptus camaldulensis), or combinations of them. A total of 40 experimental panels were manufactured from each material type. Panels were also made using a 50:50 ratio of eucalyptus and bamboo, eucalyptus and rice straw, and bamboo and rice straw; a 50:25:25 ratio of eucalyptus, rice straw, and bamboo; and a 70:15:15 ratio of eucalyptus, rice straw, and bamboo, respectively. Average target density of the panels ranged from 0.75 to 0.78 g/cm 3. Modulus of rupture, modulus of elasticity, internal bond strength, thickness swelling, water absorption, density profiles, and surface roughness of the specimens were determined. Panels with 50:50 bamboo and eucalyptus particles resulted in the highest mechanical properties followed by panels made from 100 percent bamboo. Boards manufactured with 100 percent rice straw produced the lowest properties. The amount of rice straw in the panels significantly reduced both physical and mechanical properties of the samples. The overall panel properties improved as lower percentage of rice straw were added to the mats. Based on initial results of this study, three under-utilized species can be used to manufacture value-added particleboard panels. It also appears that an addition of rice straw into the mats should be less than 15 percent to achieve better panel properties.