| 1. |
- Izekor, David, et al.
(författare)
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Effects of geometric particle sizes of wood flour on strength and dimensional properties of wood plastic composites
- 2013
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Ingår i: Journal of Applied and Natural Science. - : Applied and Natural Science Foundation. - 0974-9411 .- 2231-5209. ; 5:1, s. 194-199
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Tidskriftsartikel (refereegranskat)abstract
- The effect of different wood flour sizes on strength and dimensional properties of wood-plastic compositeswere examined. Wood flour of different particle sizes viz; 1.00mm, 2.00mm and >2.00mm were compounded withrecycled low-density polyethylene (LDPE) at different wood/plastic ratio of 1: 1, 2: 3 and 3: 2. The results obtainedshowed that wood flour size > 2.00mm has the highest MOR and MOE values of 1.206N mm-2 and 2484.72Nmm-2while wood flour size of 1.00mm had the lowest MOR and MOE values of 0.505Nmm-2 and 2195.89Nmm-2 respectively.Also the results of the physical properties showed that wood flour size of 1.00mm had the lowest thickness swellingpercentage with mean values of 0.28% and 2.08% while water absorption percentage has mean values of 0.91%and 10.58% after 2 hours and 24 hours of water immersion respectively. It was observed that wood flour size of2.00mm and particle size >2.00mm had the highest thickness swelling and water absorption percentages. Thisshowed that strength properties of wood plastic composites increased with increased particle sizes whereas itsdimensional properties increased with decreased particle sizes. The results of analysis of variance carried out onmechanical and physical properties showed that particle sizes and wood/plastic ratio had a significant effect on themechanical and physical properties of wood plastic composites (p 0.05).
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| 2. |
- Alawode, Abiodun, et al.
(författare)
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Evaluation of Irvingia kernels extract as biobased wood adhesive
- 2020
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Ingår i: Journal of Wood Science. - : Springer. - 1435-0211 .- 1611-4663. ; 66
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Tidskriftsartikel (refereegranskat)abstract
- Irvingia tree species have been earmarked for domestication in many countries due to their potential as raw materials for various applications, which include biodiesel, cosmetics, perfume, soap, etc. Presently, there is no information on the utilization of kernel seed extract as a potential source of green wood adhesive. This study is focused on investigating the properties of adhesives produced from kernel seeds of two Irvingia wood species i.e. Irvingia gabonensis (IG) and Irvingia wombolu (IW), as well as investigating the improved properties derived from the effect of modification using a few selected modifying agents including glutaraldehyde, glyoxal, epichlorohydrin (EPI) and an acid/base type process modification. Polyethylene (PE) was used along with the glutaraldehyde, glyoxal and epichlorohydrin modifiers in the modification process. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) were conducted to study the effect of modification on adhesive properties. The glycosidic carbon of the unmodified extracts and that of the EPI modified sample were not sensitive to chain conformations. Principal components (PC) 1 and 2 explained 85.19 and 9.54%, respectively, of the total variability in FTIR spectra among the modified and unmodified adhesives. The unmodified samples for IG and IW exhibited one peak with crystallization temperatures of 18.7 and 14.4 °C, respectively, indicating only one component exhibits some low degree crystallinity. The adhesive properties of the modified extracts were tested on wood veneers according to ASTM standard. The shear strength of the modified adhesives ranged from 1.5 to 3.93 MPa and 1.7 to 4.05 MPa for IG and IW, respectively. The modified samples containing PE showed marked improvement in the shear strength. The highest values were about 63% higher than the shear strength of unmodified samples with least shear strength. The results indicated that the modification of Irvingia-based adhesives had a great contribution to their performance as natural wood adhesives.
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| 3. |
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| 4. |
- Alawode, Abiodun, et al.
(författare)
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Performance evaluation of a natural based adhesive derived from Irvingia wood species kernel extracts on wood panel production
- 2020
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Ingår i: Journal of Adhesion Science and Technology. - : Taylor & Francis. - 0169-4243 .- 1568-5616. ; 34:9, s. 995-1012
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Tidskriftsartikel (refereegranskat)abstract
- Irvingia seed kernels have been identified as potential raw materials for a wide range of applications such as biodiesel, cosmetics, perfume, and soap. As a result, the Irvingia wood species is earmarked for domestication globally in order to commercially exploit these potential benefits. This study investigated the physical and mechanical properties of experimental panels made with pine (Pinus elliottii) wood particles, using modified Irvingia gabonensis (IG) and Irvingia wombolu (IW) extracts as a binder. The mean values of modulus of rupture (MOR) and modulus of elasticity (MOE) for the panels produced with this Irvingia-based adhesive were 5.8 and 1251 MPa, respectively. These values are within the minimum requirement for MOR and MOE (5.5 and 1034 MPa, respectively) for panel grade 1-L-1 as specified by the American National Standards Institute A208.1. The results from the study show that Irvingia kernel extracts may be considered as a potential environmentally friendly adhesive for wood composite manufacture.
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| 5. |
- Alawode, Abiodun, et al.
(författare)
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Properties and characteristics of novel formaldehyde-free wood adhesives prepared from Irvingia gabonensis and Irvingia wombolu seed kernel extracts
- 2019
-
Ingår i: International Journal of Adhesion and Adhesives. - : Elsevier. - 0143-7496 .- 1879-0127. ; 95
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Tidskriftsartikel (refereegranskat)abstract
- There is renewed interest in the domestication of Irvingia tree species due to the potential use of various parts of the tree as raw materials for a wide range of applications such as biodiesel production, cosmetics, perfumes, soap, weight-loss supplement etc. The current study investigates the properties of extracts from the seed kernels of two Irvingia species – Irvingia gabonensis (IG) and Irvingia wombolu (IW) as natural wood adhesives. Three extraction methods using various solvent/solute media were compared in terms of yield, composition and mechanical properties. Statistically, the analysis revealed significant differences between the different extraction methods. The adhesion properties of the extracts were tested on wood veneers according to the American Society for Testing and Materials standard (ASTM D – 906-64). The shear strength of the extracts ranged from 0.55 to 1.5 MPa and 0.86 to 1.7 MPa for IG and IW, respectively. The initial decomposition temperature of all Irvingia Kernel extract ranges from 138.3 – 149.11 oC for IG and 129.5 – 145.3 oC for IW. As a result, the hot melt temperature for the adhesive experiments was set around 150 oC. The results indicate that Irvingia kernel extract is a more promising source of non-formaldehyde based adhesives in wood composite production.
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| 6. |
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| 7. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Assessment of the physical and mechanical properties of treated Kenaf fibre cement composites
- 2015
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Ingår i: Ife Journal of Technology. - 1115-9782. ; 23:2, s. 14-17
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effect of pretreatment on theproperties of kenaf fibre cement boards. Homogenous fibre cementboards were made from kenaf bast fibres, cement and water. Thefibres were cut into smaller sizes, mixed with cement and water andformed in rectangular moulds. After demoulding, the boards werecured for 28 days. The boards were manufactured at threepretreatment levels which include hot water, 3% CaCl2, hot water and 3% CaCl2 and a control. The fibre cement boards were tested forModulus of Rupture (MOR), Modulus of Elasticity (MOE), InternalBonding (IB), Water Absorption (WA), Thickness Swelling (TS) andLinear Expansion (LE). Also nail ability and withdrawal resistance,termite, fungi and fire resistances were also assessed. The resultsshowed that the mean MOR ranged from 1.31 to 8.25 N/mm2; the meanMOE from 78.0 to 1636.3 N/mm2 for all treated boards. Mean waterabsorption ranged from 27.52% to 67.64% and the mean thicknessswelling from 14.51% to 48.01% for all treated boards. Statisticalanalysis showed that the effects of the pretreatments were significanton the properties evaluated (p < 0.05). The study concluded that hotwater combined with CaCl2 treated boards exhibited the bestmechanical and physical properties.
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| 8. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Bioenergy production and utilization in different sectors in Sweden: A state of the art review
- 2020
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Ingår i: BioResources. - : University of North Carolina Press. - 1930-2126. ; 15:4, s. 9834-9857
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Forskningsöversikt (refereegranskat)abstract
- In the continual desire to reduce the environmental footprints of human activities, research efforts to provide cleaner energy is increasingly becoming vital. The effect of climate change on present and future existence, sustainable processes, and utilizations of renewable resources have been active topics within international discourse. In order to reduce the greenhouse gases emissions from traditional materials and processes, there has been a shift to more environmental friendly alternatives. The conversion of biomass to bioenergy, including biofuels has been considered to contribute to the future of climate change mitigation, although there are concerns about carbon balance from forest utilization. Bioenergy accounts for more than one-third of all energy used in Sweden and biomass has provided about 60% of the fuel for district heating. Apart from heat and electricity supply, the transport sector, with about 30% of global energy use, has a significant role in a sustainable bioenergy system. This review presents the state of the art in the Swedish bioenergy sector based on literature and Swedish Energy Agency’s current statistics. The review also discusses the overall bioenergy production and utilization in different sectors in Sweden. The current potential, challenges, and environmental considerations of bioenergy production are also discussed.
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| 9. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Calcium phosphate bonded wood and fiber composite panels : production and optimization of panel properties
- 2017
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Ingår i: Holzforschung. - Germany : Walter de Gruyter. - 0018-3830 .- 1437-434X. ; 71:9, s. 725-732
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Tidskriftsartikel (refereegranskat)abstract
- The development of phosphate bonded composites with properties comparable with those of current Portland cement bonded products has been investigated. More precisely, the focus of the study was the optimization of calcium phosphate cements in combination with wood processing residues slash pine (Pinus elliottii Engelm.) planer shavings, Black wattle (Acacia mearnsii De Wild.) residues, Blue gum (Eucalyptus globulus Labill.) residues, hemp (Cannabis Sativa L.) hurds and dried crushed sugarcane bagasse (Saccharum officinarum L.) as well as pulp mill sludge and waste paper. A central composite design (CCD) for the response surface methodology (RSM) was applied for selection of the proper parameters. Mechanical tests were conducted on the composite products and the effect of the processing variables was evaluated based on the Pareto analysis of variance. The density of the wood-based panels ranged from 0.68 to 1.21 g cm−3, that of the agricultural fibers from 0.59 to 1.15 g cm−3 and that of the paper pulp panels from 0.81 to 1.21 g cm−3. The modulus of elasticity (MOE) data of the panels ranged from 1.63 to 4.92 MPa for wood, from 0.37 to 3.28 MPa for agricultural fibers and from 0.65 to 3.87 MPa for paper-pulp-based fibers. The physical properties of the composite products met the requirements for Portland-cement-bonded particleboards (EN 634-2, 2007).
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| 10. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Effect of bark on the physical and mechanical properties of phosphate bonded wood composites of black wattle (Acacia mearnsii De Wild)
- 2016
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Ingår i: Forest resource and Products: Moving toward a sustainable future, 59th International Convention of the Society of Wood Science and Technology, Curitiba, Brazil, March 6 -10, 2016. - Curitiba, Brazil. - 9780981787664 ; , s. 165-173
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Konferensbidrag (refereegranskat)
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| 11. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Effect of wood particle geometry and pre-treatments on the strength and sorption properties of cement-bonded particle boards
- 2013
-
Ingår i: Journal of Applied and Natural Science. - : Applied and Natural Science Foundation. - 0974-9411 .- 2231-5209. ; 5:2, s. 318-322
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Tidskriftsartikel (refereegranskat)abstract
- The effect of particle geometry and pretreatments on the strength and sorption properties of wood particlecement composite boards was investigated. Wood particles (flakes and sawdust) of Gmelina arborea were mixedwith cement and water in the production of composite boards. The wood particles were pretreated with hot water,calcium chloride and a combination of both treatments to enhance bonding with cement. The slurry was poured intorectangular moulds for board formation. After demoulding, the boards formed were tested for modulus of rupture(MOR), modulus of elasticity (MOE), water absorption (WA) and thickness swelling (TS). The results revealed thatthe mean MOR for flakes boards was 3.23N mm-2 while the mean MOR for sawdust boards was 3.01N mm-2. Hotwater and calcium chloride treatment produced the best effect in flake composite boards with MOR and MOE valuesof 6.90 N/mm2 and 1897.36 N mm-2 while sawdust composite boards had mean MOR and MOE values of 5.69Nmm-2 and 1664.31N mm-2 respectively. The WA rate after 24 hours of flakes and sawdust boards treated with hotwater and calcium chloride was 3.63% and 4.28% while the TS rate was 0.69% and 1.44% respectively. Particlegeometry and pretreatments significantly improved strength and sorption properties of wood particle cementcomposite boards (p<0.05).
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| 12. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Evaluation of cement-bonded particleboards produced from mixed sawmill residues
- 2021
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Ingår i: Journal of the Indian Academy of Wood Science. - : Springer. - 0972-172X .- 0976-8432. ; 18:1, s. 14-19
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluates the application feasibility and properties of cement-bonded particleboards produced from mixed tropical hardwood species. Wood residues from a typical sawmill were collected, dried and used in the manufacturing of the cement composites. The wood residues used were from Ceiba pentandra and Gmelina arborea timber species. The residues were mixed in seven ratios in the production of the composite samples. Two control experimental samples containing unmixed residues of each species were also produced. The test carried out on the boards were flexural strength, water uptake properties and wet and dry screw withdrawal resistance. The effect of the wood mix ratio on the board properties was evaluated. The result showed that all properties except the screw withdrawal resistance were significantly influenced by the mix ratios (p < 0.05). The wet and dry screw withdrawal resistance ranged from 1170 to 1770 N and 1360 to 1830 N, respectively. The optimum wood mix ratio for enhancing mechanical performance of the boards was 1:4 of C. pentandra/G. arborea wood residues. Based on the result of this study, the particleboards produced can be used as wood composite ceiling tiles in building applications.
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| 13. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Magnesium based phosphate cement binder for composite panels: A response surface methodology for optimisation of processing variables in boards produced from agricultural and wood processing industrial residues
- 2016
-
Ingår i: Industrial crops and products (Print). - : Elsevier. - 0926-6690 .- 1872-633X. ; 94, s. 746-754
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates the potential use of magnesium based phosphate cement prepared from a heavy magnesium oxide and monopotassium phosphate as a binder for the production of composite panels using bio-based industrial residues such as bagasse, hemp hurds, pine sawdust, paper mill sludge and wastepaper as raw materials. These residues were used to produce light-weight and durable materials that can compare with current Portland cement based products. The phosphate binder is fast setting, cold curing and has a low carbon footprint compared to its Portland cement counterpart. The development of phosphate bonded board products promises to reduce the energy requirements in the manufacturing process of board products, and also provides an alternative route for disposal or value addition to bio-based residues by developing environmentally friendly products. The board manufacturing process was laid out on a central composite design (CCD) to model the response variable, utilizing as much residues as technically feasible. The design allowed for the production of low and medium density boards that can be used for non-structural interior finishes and partition boards. Response surface methodology (RSM) was used to show the relationships between the production variables and predict the board property by variable optimisation. Tests of mechanical and physical properties were conducted on the boards. The density of hemp boards ranged from 0.59–0.83 g/cm3, bagasse boards ranged from 0.54–0.78 g/cm3, pine boards ranged from 0.58–0.84 g/cm3, paper sludge boards ranged from 0.68–0.81 g/cm3 and wastepaper boards ranged from 0.67–0.81 g/cm3. The study has shown that it is feasible to produce phosphate based board products using bio based industrial and agricultural residues. The physical properties of the products met the minimum requirements for cement bonded particleboard (EN 634:2007) and LD-1 grade particle board (ANSI 208.1:1999).
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| 14. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Natural fibre modification and its influence on fibre-matrix interfacial properties in biocomposite materials
- 2020
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Ingår i: Fibers And Polymers. - : Springer. - 1229-9197 .- 1875-0052. ; 21:4, s. 677-689
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Forskningsöversikt (refereegranskat)abstract
- Biocomposite materials manufactured from natural fibres and polymer matrix represent a group of engineered composite products with diverse applications. These materials continue to find increasing applications due to their design flexibility, superior properties and aesthetic appeal. The applicability of these biocomposites, however, depends on theinteraction in the fibre-matrix interface. This paper reviews the state of the art research in fibre-matrix interfacial interaction based on published literature. A brief background on biocomposite materials is presented. The focus of this review is the modification of natural fibres and its effect on fibre-matrix interfacial adhesion and properties. In addition, the effect of chemical treatment on fibre composition and fibre-matrix interfacial bonding mechanism are discussed.
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| 15. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Performance characteristics of treated kenaf bast fibre reinforced cement composite
- 2016
-
Ingår i: Journal of the Indian Academy of Wood Science. - India : Springer. - 0972-172X .- 0976-8432. ; 13:2, s. 156-160
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effect of pretreatment on the properties of kenaf fibre cement boards. Homogenous fibre cement boards were made from kenaf bast fibres, cement and water. The fibres were cut into smaller sizes, mixed with cement and water and formed in rectangular moulds. After demoulding, the boards were cured for 28 days. The fibres were treated at three levels which included hot water, calcium chloride (CaCl2), hot water + CaCl2 and a control (untreated). The fibre cement boards were tested for Modulus of Rupture (MOR), Modulus of Elasticity (MOE), Internal Bond (IB), Water Absorption (WA), Thickness Swelling (TS) and Linear Expansion (LE). The results showed that the mean MOR ranged from 1.31 to 8.25 MPa; the mean MOE from 78.0 to 1636.3 MPa for all treated boards. Mean water absorption ranged from 27.52 to 67.64% and the mean thickness swelling from 14.51 to 48.01% for all treated boards. Statistical analysis showed that the effect of the pretreatment was significant on the properties evaluated (p < 0.05). The study concluded that boards produced from hot water combined with CaCl2 treated fibres exhibited the best mechanical and physical properties.
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| 16. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Phosphate bonded natural fibre composites
- 2017
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Ingår i: Forest Sector Innovations for a Greener Future, June 12-16, 2017. - Vancouver, Canada : International Union of Forest Research Organizations.
-
Konferensbidrag (refereegranskat)abstract
- The demands for wood based composites along with increasing economic and environmental concerns on conventional wood products necessitate moving beyond the traditional processing methods to more costeffectiveand environmentally friendly approaches. In the wake of a fast-setting phosphate binder with a low carbon footprint, this study investigates the potential of different waste residues incorporated in formulated magnesium and calcium phosphate binders to produce commercially-viable composite products. The residues include forest waste from alien invasive trees, agricultural processing waste such as bagasse and hemp hurds, and wood-based industrial residues including papermill sludge, waste paper and sawmill waste. A wide range of composite products were produced that met the requirements of Portland cement particleboard (EN 634: 2007). This study presents the result of the process optimization and test conducted to product technical specifications. The development of phosphate bonded natural fibre composites utilizing lignocellulosic residues promises to bring economic potential to developing countries.
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| 17. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Phosphate bonded natural fibre composites : a state of the art assessment
- 2019
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Ingår i: SN Applied Sciences. - : Springer. - 2523-3963 .- 2523-3971. ; 1:8
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Forskningsöversikt (refereegranskat)abstract
- Over the last few decades, innovative wood composite products and processes have created markets for new and existing products. Inorganic bonded fibre composites have been developed for high performance applications using conventional cement and concrete. The demands for wood based composites along with increasing economic and environmental concerns on conventional wood products necessitate moving beyond the traditional processing methods to more cost-effective and environmentally friendly approaches. In the wake of the twenty-first century, a fast-setting phosphate binder with a low carbon footprint was developed, which can alternatively be utilized in wood composite development. This paper reviews the recent progress in phosphate bonded composite products, based on published literature from the last two decades. A brief background on Portland cement based natural fibre composites is presented. In addition, the mechanism of the formulation of phosphate binders, the effect of aggregates in the materials and the environmental benefits accruable to such materials are discussed.
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| 18. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Phosphate bonded wood composite products from invasive Acacia trees occurring on the Cape Coastal plains of South Africa
- 2018
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Ingår i: European Journal of Wood and Wood Products. - : Springer. - 0018-3768 .- 1436-736X. ; 76:2, s. 437-444
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Tidskriftsartikel (refereegranskat)abstract
- The feasibility of manufacturing phosphatebonded wood composite board products from four locallyoccurring invasive acacia tree species (Acacia cyclops, A.saligna, A. mearnsii and A. longifolia) was studied usinga formulated magnesium oxide (MgO) and monopotassiumphosphate (KH2PO4) binder system. The optimizationfor the manufacturing process was studied using a centralcomposite statistical design, whereupon the following factorswere considered, i.e. KH2PO4:MgO ratio, the fly ashcontent as partial replacement for the binder and the woodcontent as a ratio of wood to the total inorganic content.A fitted response surface plot was used to show the effectof the main factors and their interactions on the measuredboard properties. A response surface model was developedto predict the parameters leading to the best board properties.All physical properties evaluated met or exceededthe minimum requirements for low density particleboards.The results showed that the variables considered have significanteffects on the physical properties of the boards.The optimum composite manufacturing process for makingdurable products within the scope of the studied specieswas found to be a KH2PO4/MgO ratio of 1.66, an ashcontent of 2.7% and a wood/inorganic ratio of 0.96 for theselected wood species.
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| 19. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Recycled waste paper-cement composite panels reinforced with kenaf fibres : durability and mechanical properties
- 2020
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Ingår i: Journal of Material Cycles and Waste Management. - : Springer. - 1438-4957 .- 1611-8227. ; 22:5, s. 1492-1500
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Tidskriftsartikel (refereegranskat)abstract
- There is a growing interest on recycling of waste fibres as an alternative to landfill disposal. The aim of the study was to investigate the durability and mechanical properties of waste paper-cement composite panels reinforced with varying kenaf fibre content (FC, 2-10%). The panels produced were evaluated for properties including modulus of rupture (MOR) and apparent modulus of elasticity (MOE). The resistance of the panels was tested in the field for both termite damage and fungi decay for a period of 24 weeks. Accelerated decay test was also performed on selected samples. The results showed that the mean MOR ranged from 3.17 MPa for samples with 10% FC to 4.84 MPa for samples with 8% FC. The mean MOE ranged from 248 MPa for samples with 10% FC to 1298.1 MPa for samples with 8% FC. Statistical analysis showed that the effect of the fibre content was significant on the properties evaluated (p<0.05). The study concluded that the optimum fibre content for improving strength and physical properties of paper-cement composites in a ratio of 1:1 (w/w) using kenaf as reinforcing fibre is 8%. The panels were highly resistant to both termite and fungi attack for the study duration.
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| 20. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Recycling sawmilling wood chips, biomass combustion residues, and tyre fibres into cement-bonded composites : Properties of composites and life cycle analysis
- 2021
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Ingår i: Construction and Building Materials. - : Elsevier Ltd. - 0950-0618 .- 1879-0526. ; 297
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the properties and sustainability of cement-bonded composites containing industrial residues such as wood chips, tyre fibres and biomass combustion residues, i.e. bottom ash (BA) and fly ash (FA). The effect of cement-to-raw material (wood/tyre fibre) ratio (C/RM) and the aggregate content (BA and FA) on thermal and mechanical properties of the composites were investigated. Scanning electron microscopy (SEM) and life cycle analysis (LCA) were also conducted. The results revealed that as the aggregate content increased in wood composites, the mechanical properties also increased. The mean thermal conductivity and volumetric heat capacity of tyre composite samples were 0.37 W/mK and 1.2 MJ/m3K respectively, while the respective values for wood composite samples were 0.29 W/mK and 0.81 MJ/m3K. SEM analysis showed adequate bonding between wood/tyre fibres and cement matrix. LCA revealed that the materials share of the total primary energy use was about 60% for all analysed composites. © 2021 The Author(s)
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| 21. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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Shrinkage characteristics of plantation grown Teak (Tectonal grandis Linn.) in Edo State, Nigeria
- 2017
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Ingår i: “Forest Sector Innovations for a Greener Future”, 2017 IUFRO Division 5 Conference and 60<sup>th</sup> Society of Wood Science and Technology (SWST) International Convention, Vancouver, BC, Canada, 12<sup>th</sup> - 16<sup>th</sup> June 2017.. - Vancouver, BC, Canada.
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Konferensbidrag (refereegranskat)
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| 22. |
- Amiandamhen, Stephen, 1983-
(författare)
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Technology and market opportunities in fiber cement composites for small scale enterprises in Nigeria
- 2013
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Ingår i: Global Journal of Agricultural Sciences. - : Global Journal Series. - 1596-2903. ; 12, s. 11-14
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Tidskriftsartikel (refereegranskat)abstract
- Solving problems of unemployment and developing new materials for buildings requires moving beyond the traditional approaches to more economical, environmentally benign performance models and design properties. New approaches should develop models based on the literature and a full understanding of the root causes of failure, derived from careful failure analysis. One of the main drivers of the development efforts in fibre based composites is the trend towards greater environmental awareness and the health hazards associated with the utilization of asbestos fibres. The key to effectively developing marketable fibre cement composites for use as building materials that can be used for construction of safe and affordable structures is to identify the research and development and market needs for such products. This paper looks into the empirical production and market opportunities in terms of product performance accruable to locally manufactured fibre cement ceiling boards.
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| 23. |
- Amiandamhen, Stephen, 1983-, et al.
(författare)
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The effect of chemical treatments of natural fibres on the properties of phosphate‑bonded composite products
- 2018
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Ingår i: Wood Science and Technology. - : Springer. - 0043-7719 .- 1432-5225. ; 52:3, s. 653-675
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Tidskriftsartikel (refereegranskat)abstract
- Phosphate-bonded composites are an emerging class of building materials produced from natural fibres and phosphate based cement pastes. They are durable and possess mechanical properties similar to those of Portland cement. However, the moisture absorption of natural fibre can lead to swelling which may result in the reduction in the mechanical strength properties and eventually negatively affect the long-term performance and dimensional stability of the products. This study was aimed at the modification of some properties of selected biomaterial residues in order to enhance the final properties of the phosphate-bonded composite product. Three different treatments were evaluated viz. 1% caustic alkali, 1% acetic anhydride and hot water on natural fibres derived from slash pine, black wattle and bagasse. The effect of the treatment on the fibres was evaluated via HPLC, SEM and FTIR. Further, the performance of the treated fibres was evaluated in composite panels bonded with magnesium phosphate (MgPO4) and calcium phosphate (CaPO4) cement pastes against the controls. The manufactured panels were tested for flexural properties and dimensional stability. In the MgPO4-bonded panels, the MOR increased from 0.55 MPa for untreated bagasse panels to 0.79 MPa for alkalised panels. Similarly, the MOE increased from 150.04 MPa for untreated bagasse panels to 175.65 MPa for alkalised panels. In untreated MgPO4-bonded panels, the mean density was 0.76, 078 and 0.75 g/cm3, while in alkalised panels, the mean density was 0.81, 0.81 and 0.81 g/cm3 for wattle, pine and bagasse panels, respectively. In the bagasse panels, the water absorption was 54.61% for untreated, 48.74% for hot water extracted, 42.21% for acetylated and 36.44% for alkalised MgPO4-bonded panels. This represents a percentage improvement of 11, 23 and 33%, respectively. Alkali-treated fibres had the best effect overall for all measured properties.
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| 24. |
- Chimphango, Anderson, et al.
(författare)
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Prospects for Paper Sludge in Magnesium Phosphate Cement:Composite Board Properties and Techno‑Economic Analysis
- 2021
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Ingår i: Waste and Biomass Valorization. - : Springer Nature. - 1877-2641 .- 1877-265X. ; 12, s. 5211-5233
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the feasibility of utilizing paper sludge (PS) as feedstock in the production of composite boards thatare lightweight, durable and environmentally friendly. PS samples were collected from recycled newsprint (RN), corrugatedrecycled (CR) and virgin pulp (VP) pulping mills in South Africa. The PS was dried and mixed with magnesium phosphatecement to produce boards in a central composite design. Three different fillers including fly ash, calcium carbonate and silicafume were also added to the mix as binder replacement. The PS was characterized before use, and the produced compositeboard was evaluated for mechanical and physical properties. The boards produced had medium to high density (0.52—1.12 g/cm3) that could be used for non-structural interior applications. The results showed that boards containing RN had the highestmean value for modulus of elasticity (MOE) of 769 MPa. The mean MOE for boards containing CR- and VP-PS was357 and 411 MPa, respectively. Calcium carbonate had the best effect on the board properties. Techno-economic analysiswas simulated for four different types of feedstock scenarios at different locations including a combined scenario. Sensitivityanalysis revealed that decreased feedstock cost resulted in decreased minimum required selling price. The analysis alsorevealed that the combined scenario proved to be the most cost-effective and profitable option for the future.
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| 25. |
- Foti, Dafni, et al.
(författare)
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Microstructure and compressive strength of gypsum-bonded composites with papers, paperboards and Tetra Pak recycled materials
- 2019
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Ingår i: Journal of Wood Science. - : Springer. - 1435-0211 .- 1611-4663. ; 65:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The incorporation of recycled papers, paperboards and Tetra Pak as filling materials in brittle matrices presents aninteresting approach in the utilization of waste materials for building construction. This paper examines the compressivestrength and microstructure of gypsum-bonded wastepaper-based composites. Recycled wastepaper of varioustypes (office paper, magazine paper and newspaper), cardboards, paper boxes and Tetra Pak were shredded to shortlength strips of about 4 × 18 mm. The shredded materials were used as filling materials in natural gypsum in a ratioof 1:3 (v/v), and water was added to the mix. The paste was formed in cylindrical samples measuring 10 cm in lengthand 5 cm in diameter. Seven different types of composites were produced depending on the material used. Thecomposite products with newspaper and magazine paper had significantly lower density and compressive strength(p < 0.05) than the others. However, the differences were small to have any practical importance. The density valuesranged between 1.26 and 1.34 g/cm3, and compressive strength was the lowest (4.48 N/mm2) in the gypsum–magazinepaper composites and the highest (6.46 N/mm2) in the gypsum–Tetra Pak I composites. Since the samplesproduced in this study exhibited adequate compressive strength, the products could be suitable for such applicationsas interior walls in building constructions. Scanning electron microscopy (SEM) examination of the fractured surfacesrevealed needle-like structures of gypsite crystals surrounding the fibers, which indicates good adhesion between thehydrophobic matrix and lignocellulosic fibers.
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| 26. |
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| 27. |
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| 28. |
- Izekor, David, et al.
(författare)
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Effect of taper and sawing methods on log conversion among selected sawmills in Edo State, Nigeria
- 2016
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Ingår i: Nigerian Journal of Forestry. ; 46:1-2, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- This study was carried out to determine the effect of taper and sawing methods on log conversion among selected sawmills in Egor andOvia-North East Local Government Areas of Edo State. Ten representative sawmills and thirty round logs were sampled for eachspecies making a total of 300 logs based on the relative abundance of available timber species were sampled. The diameter of the logs,length and girth at small and large ends were measured before conversion. The data were analyzed using descriptive statistics. Theresults obtained showed that Egor Local Government Area has the highest frequency of the selected species representing 56% of totallogs sampled while Ovia North-East Local Government Area has 44% of total logs sampled. Conversion efficiency varied from 56.49to 76.26%. Factors such as inherent defect in the timber, age of the machine and the severity of the log taper affected conversionefficiency at the sawmills. Lumber recovery efficiency increases with bigger log, short log length and narrower taper. Therefore, logsize, taper and log length have positive relationship on lumber recovery efficiency.
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| 29. |
- Izekor, David, et al.
(författare)
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Utilization of fuelwood as household energy among residents of Benin metropolis, Edo State, Nigeria
- 2017
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Ingår i: Nigerian Journal of Agriculture, Food and Environment. - 0331-0787. ; 13:2, s. 174-178
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Tidskriftsartikel (refereegranskat)abstract
- The study evaluates the utilization of fuelwood as household energy among residents in Benin metropolis. Its utilization andavailability as household energy source as well as reasons for its preference to other household energy sources was assessed.A random sampling technique was used to select 10 communities within the study area namely; Uselu, Siluko, Uwelu, Ogbaarea, Airport road, Ekehuan, Evbotubu, Aduwawa - Urora quarters, Upper sakponba The survey was carried out in theseareas with the aid of a semi-structured questionnaire administered to respondents who utilize and sell fuelwood in thesecommunities. A total of 200 copies of questionnaire were administered. The main variables measured were those of fuel woodconsumption, availability and sources of fuelwood utilization. The results showed that the 50% of the respondents utilizedfuelwood as their source of domestic house hold energy. 51% of the respondents sourced their fuelwood from fuelwoodvendors while 25% source for fuelwood from their local farmland. 60% of the respondents in the study area spent an averageof N200 daily on fuelwood while 52% of the respondents have a weekly expense of above N700 on fuel wood utilization. Theaverage weekly consumption of fuelwood by 50% of the respondents was between 22 – 27 kg. Hevea braziliensis representing33% of fuelwood species was the most abundant fuelwood consumed by residents in the study araea. The results from T-testand Pearson correlation showed that there was a significant difference in the amount of fuelwood consumed in the differentcommunities within the study area. Therefore the quantity of fuelwood consumed is related to the number of persons perhousehold.
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| 30. |
- Kumar, Anuj, et al.
(författare)
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Forest Biomass Availability and Utilization Potential in Sweden : A Review
- 2021
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Ingår i: Waste and Biomass Valorization. - : Springer. - 1877-2641 .- 1877-265X. ; 12:1, s. 65-80
-
Forskningsöversikt (refereegranskat)abstract
- In recent years, there has been a growing interest in many parts of the world for more effective biomass utilization due to legislative and public interest in sustainable development. Whilst much of the effort has been on energy generation from biomass, there is considerable interest on biomass availability and utilization for other end uses. With about 1% of the world’s commercial forest areas, Sweden provides about 10% of the sawnwood, and pulp and paper that is traded on the global market. The Swedish agricultural sector also contributes to biomass availability, not only by production of sustainable food crops, but also by utilizing side streams and underutilized land for biomaterial purposes. To meet the challenges that climate change presents, there has to be a shift to sustainable biomass production and increased interest in promoting a circular bioeconomy. This review presents a systematic assessment on the availability of biomass and its utilization potential in Sweden. The review also focuses on biomass production and trade in the Swedish forest industry. In addition, the environmental impact of biomass utilization is discussed.
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| 31. |
- Kuqo, Aldi, et al.
(författare)
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Enhancement of physico-mechanical properties of geopolymer particleboards through the use of seagrass fibers
- 2023
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Ingår i: Construction and Building Materials. - : Elsevier. - 0950-0618 .- 1879-0526. ; 374
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Tidskriftsartikel (refereegranskat)abstract
- Two types of geopolymer-bonded boards were produced using initial wetting of lignocellulosic aggregates followed by dry mixing and hot-pressing. Boards were prepared by incorporating large fractions of lignocellulosic material (up to 50 wt%). Geopolymer particleboards (GP) were produced using wood particles whereas geopolymer sandwich boards (GSB) were produced from wood particles and seagrass fibers, with the latter allocated in the outer layers. Inclusion of seagrass fibers was found to enhance bending strength and toughness of GSB by up to 20 and 40 % respectively. The bending strength tended to increase with the addition of lignocellulosic aggregates, reaching up to 8.9 N mm−2. Fire resistance of GSB was slightly higher compared to GP. Further investigations such as FT-IR, XRD analysis and visual examination by digital microscopy showed an adequate degree of geopolymerization and mixing of the precursor and alkaline activator, indicating the high effectiveness of the mixing technique.
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| 32. |
- Mngomezulu, Lehlohonolo, et al.
(författare)
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Influence of heat curing and aggregates on the properties of phosphate bonded biocomposites
- 2019
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Ingår i: SN Applied Sciences. - : Springer. - 2523-3963 .- 2523-3971. ; 1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- There is renewed effort in reducing the carbon footprint of conventional building materials by employing novel phosphate cements. This study investigates the influence of industrial aggregates, namely fly ash, silica fume and calcium carbonate on biocomposite properties. The biomaterials used included pine, bagasse and wattle. The density of the boards produced ranged from 0.82 to 1.16 g/cm3, and the MOE ranged from 410.57 to 1737.87 MPa. The study concluded that biomass type, curing temperature and aggregates have significant effects on the biocomposite properties. The boards produced met the physical property requirements for use as non-load-bearing structures in humid and external conditions.
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| 33. |
- Olayiwola, Hamed, et al.
(författare)
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Investigating the suitability of flyash/metakaolin-based geopolymers reinforced with South African alien invasive wood and sugarcane bagasse residues for use in outdoor conditions
- 2021
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Ingår i: European Journal of Wood and Wood Products. - : Springer. - 0018-3768 .- 1436-736X. ; 79, s. 611-627
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Tidskriftsartikel (refereegranskat)abstract
- The prevailing approach of total clearing to contain the spread of invasive plants (IP) in South Africa is generating enormouslignocellulosic wastes. This study examined the possibility of utilizing these wastes in the production of geopolymercomposites for use in outdoor environments. Untreated wood particles from Acacia mearnsii and A. longifolia, as well assugarcane bagasse residues, were incorporated into a geopolymer matrix developed from a binary precursor system of 75%fly ash and 25% metakaolin. The variables considered included precursor-activator ratio (PA), curing pattern (CP), lignocellulosicmaterial (LM), and alkali concentration (Mcon). The production process was established using a mixed factorialexperimental design. PA and CP were considered at 2 levels, while LM and MCon were considered at 3 levels. The densityof the boards exceeded 1 g cm−3 and are classified as high-density boards. The boards have comparable sorption propertiesto the cement-bonded particleboard according to the EN 632-2: 2007 standard. However, only A. longifolia boards producedwith 12 M NaOH and PA ratio of 2:1 met the mechanical strength requirements. Thermogravimetric analysis revealed thatthe boards are thermally stable. These results have shown that South African woody IPs are suitable for geopolymer woodcomposites, but there is still concern about their durability in the alkaline matrix. Scanning electron microscopy micrographsindicated mineralization of the particles and a partial degradation of hemicellulose was confirmed by Fourier transform infraredspectroscopy. Although the degraded components did not prevent geopolymer setting, there is need to further investigatethe extent and means of preventing degradation as this can derail the intended use of the product.
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| 34. |
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| 35. |
- Olayiwola, H. O., et al.
(författare)
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Characterization of unary precursor-based geopolymer bonded composite developed from ground granulated blast slag and lignocellulosic material residues
- 2022
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Ingår i: European Journal of Wood and Wood Products. - : Springer Nature. - 0018-3768 .- 1436-736X. ; 80:2, s. 377-393
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Tidskriftsartikel (refereegranskat)abstract
- The excellent properties of geopolymer composites and their ability to be synthesized from various industrial waste streams make them promising green binders in wood-based composite manufacturing. The study characterized 100% slag unary precursor-based geopolymers reinforced with lignocellulosic material residue. The residue included sugarcane bagasse (SCB), Port Jackson (Acacia saligna) and Black wattle (Acacia mearnsii). The production process was established based on a mixed factorial design using Statistica 13.3. The factors considered included a curing pattern at 2 levels, sodium hydroxide concentration at 3 levels and lignocellulose material at 3 levels. Other parameters, such as precursor-activator ratio and sodium hydroxide-silicate ratio were constant. Statistical analysis revealed that curing temperature and sodium hydroxide concentration had a significant effect on the board properties and the addition of lignocellulose material improved the flexural strength. Curing at 40 degrees C influenced the reaction kinetics, enhanced microstructural properties, and produced a dense geopolymeric matrix which resulted in improved physical and mechanical properties. However, increasing the sodium hydroxide concentration beyond 6 M caused efflorescence and deteriorated the mechanical property of A. mearnsii and bagasse boards. Partial degradation of the fibres was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis, but the degraded products did not inhibit geopolymer setting. Scanning electron microscopy indicated a uniform board structure surrounded with micro crystals of calcium silicate hydrate (C-S-H). A. saligna boards produced with 6 M NaOH and cured at 40 degrees C met the technical specification of cement-bonded particleboards for outdoor applications according to the British standard EN 634-2.
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| 36. |
- Owofadeju, Femi, et al.
(författare)
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Effect of enzymatic treatments on strength properties of unbleached Kenaf bast pulp
- 2013
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Ingår i: Bioscience Research Journal. - : Nigerian Society for Experimental Biology. - 0795-8072. ; 25:2, s. 97-102
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Tidskriftsartikel (refereegranskat)abstract
- Kenaf bast fibres were obtained from the Institute of Agricultural Research and Training (IAR & T), MoorPlantation, Ibadan. The fibres were washed with fresh water, air dried and cut into smaller pieces of 3-5cm long for ease ofpulping. These were cooked for 55 minutes at 170oC in a single batch of a digester. The pulp obtained was washed, oven-driedand soaked in distilled water and beaten at three levels of 900, 1800 and 4800 revolutions respectively. The pulp was treated withMultifect-B, an enzymatic mixture of glucanases and xylanases for 30, 60 and 120 minutes prior to handsheet making. Tear andBurst index were calculated from the resulting handsheets. The results showed that the tear strength decreased from 7.6 mN.m2/gat initial to 6.3 mN.m2/g at 120 minutes of enzyme contact for unbeaten pulp, while pulp beaten at 900 revolutions exhibitedhighest decrease in tear strength from 9.2 mN.m2/g at initial to 5.6 mN.m2/g at 120 minutes, representing a 40% decrease. Forpulp beaten at 1800 revolutions, the burst index increased from 3.1 kPa.m2/g for untreated to 3.4 kPa.m2/g at 60 minutestreatment time and decreased sharply to 2.8 kPa.m2/g at 120 minutes. However, there was no significant difference in the tearindex with the levels of beating (p < 0.05). It was concluded that enzymatic hydrolysis significantly improved burst index whileonly affecting the tear index.
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