Synergistic Effect of APP and TBC Fire-Retardants on the Physico-Mechanical Properties of Strandboard

This study explored the feasibility of fabricating fire-retardant strandboard with low mechanical properties deterioration to the physico-mechanical properties. A hybrid fire-retardant system of ammonium polyphosphate (APP) and 1,3,5-tris(2,3-dibromopropyl)-1,3,5-triazinane-2,4,6-trione (TBC) was investigated. Thermogravimetric analysis results show that both APP and TBC enhance the thermal stability and incombustibility of wood strands. An infrared spectrum was applied to investigate the effect of flame retardants on the curing behaviors of polymeric diphenylmethane diisocyanate (PMDI) resin. Based on the results of limiting oxygen index (LOI) and Cone calorimetry (CONE), APP and TBC both lead to a higher fire retardancy to strandboard. It is worth mentioning that the two flame retardants lead to evidently differential influences on the modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), and water-soaking thickness swelling (TS) properties of strandboard. Hence, a hybrid flame retardant is prominent in manufacturing strandboard with both good fire retardant and satisfying physico-mechanical properties.

Analysis of the Manufacturing Variables of Binderless Panels Made of Leaves of Olive Tree (Olea europaea L.) Pruning Waste

While the construction industry consumes more raw materials than any other industrial sector, agriculture generates a large amount of waste that is not managed properly. The olive industry produces more than 7.5 million tons of waste that could be recovered. This paper presents a new method to valorize the leaves of olive tree pruning waste consisting of the manufacture of ecologic boards without adhesives by hot pressing. In order to analyze their influence, three manufacturing variables were varied to obtain the boards: leaf type (shredded and whole leaves), temperature (130, 140 and 150 °C) and time (4, and 12 min). Twenty-four boards were made and were then tested for their mechanical, physical and thermal properties according to the EN standards. The boards showed good results of thickness swelling (TS), water absorption (WA) and of thermal conductivity and can be used as an alternative for manufacturing thermal insulation boards. With a smaller particle size of shredded leaves, longer pressing times and higher pressing temperatures, the mechanical behavior of the boards could improve. The olive leaves are a low-cost renewable resource, and manufacturing products with a long, useful life can be beneficial to the environment.

Study of Homogeneous Chipboard Manufacturing u sing Betung Bamboo (Dendrocalamus Asper) Mixed with Polyethylene Addictive

Bamboo is an evergreen plant native to Asia and America that grows at every altitude, even in unideal climate conditions. Betung bamboo or its scientific name Dendrocalamus Asper is one of the bamboo species that are easily found in peninsular Malaysia. This study examined the characteristics of Betung bamboo and its potential to manufacture chipboard. Several tests were conducted, namely modulus of elastic (MOE), modulus of rupture (MOR), thickness swelling (TS), and water absorption (WA) to evaluate the potential of Betung bamboo as the primary material in the manufacture of chipboard mixed with polyethylene as additive are the parameters considered. This study found that the composition of 70% bamboo and 30% polyethylene was produced optimum chipboard which met BS EN standards (British and European Standard). It was also found that the MOE and MOR values of the resulting chipboard exceeded the medium density board standards. For WA and TS values, the chipboard achieved the standard requirements. Thus, this study concludes that chipboard made of Betung bamboo with the addition of polyethylene is suitable to be applied for internal and external doors, and internal paneling for any commercial or domestic building and furniture.

Selected Properties of Plywood Bonded with Low-Density Polyethylene Film from Different Wood Species

In this work, the effects of wood species and thickness of low-density polyethylene (LDPE) film on the properties of environmentally-friendly plywood were studied. Rotary-cut veneers from four wood species (beech, birch, hornbeam and poplar) and LDPE film of four thicknesses (50, 80, 100 and 150 µm) as an adhesive were used for making plywood samples. The findings of this study demonstrated that plywood samples using all the investigated wood species bonded with LDPE film showed satisfactory physical–mechanical properties. Poplar veneer provided the lowest values for bending strength, modulus of elasticity and thickness swelling of all the plywood samples, but the bonding strength was at the same level as birch and hornbeam veneer. Beech plywood samples had the best mechanical properties. An increase in LDPE film thickness improved the physical–mechanical properties of plastic-bonded plywood.

Effect of Water Absorption Behaviour on Tensile Properties of Hybrid Jute-Roselle Woven Fibre Reinforced Polyester Composites

Incorporating natural fibre as reinforcement in the polymer matrix has shown a negative effect since the natural fibre is hydrophilic. The natural fibre easily absorbs water which causes an effect on the mechanical properties of the composites. The objective of this paper is to investigate the water absorption behaviour of hybrid jute-roselle woven fibre reinforced unsaturated polyester composite and the effect of water absorption in terms of tensile strength and tensile modulus. The effect of hybrid composite on the thickness swelling will be tested. The fabrication method used in this study is the hand lay-up technique to fabricate 2-layer and 3-layer composites with layering sequences of woven jute (J)/roselle (Ro) fibre. The results of the study showed that pure roselle fibres for 2 and 3-layer composites have the highest water absorption behaviour 3.86% and 5.51%, respectively, in 28 days) as well as thickness swelling effect, whereas hybrid J-Ro and J-J-Ro composites showed the least water absorption (2.65% and 3.76%, respectively) in 28 days) in both the tests. The hybridisation between jute and roselle fibres reduced water absorption behaviour and improved the fibres dimensional stability. The entire composites showed a decreasing trend for both tensile strength and tensile modulus strength after five weeks of water immersion. Jute fibre composite hybridised with roselle fibre can be used to reduce the total reduction of both tensile strength and tensile modulus throughout the whole immersion period. Moreover, the tensile testing showed that jute fibre composite hybridised with roselle fibre have produced the strongest composite with the highest tensile and modulus strength compared to other types of composites. The hybridisation of diverse fibre reinforcements aids in minimising the composite water absorption and thickness swelling, hence reducing the effect of tensile characteristics.

Evaluation of Functional Features of Lignocellulosic Particle Composites Containing Biopolymer Binders

In this research, the assessment of the impact of natural biopolymer binders on selected mechanical and physical properties of lignocellulosic composites manufactured with different resination (12%, 15%, 20%). Different mechanical and physical properties were determined: modulus of rupture, modulus of elasticity, internal bonding strength, thickness swelling, water absorption, contact angle, and density profile. Moreover, thermal properties such as thermogravimetric analysis and differential scanning calorimetry were studied for the polymers. The results showed significant improvement of characterized features of the composites produced using biopolymers. However, the rise of the properties was visible when the binder content raised from 12% to 15%. Further increase of biopolymer binder did not imply a considerable change. The most promising biopolymer within the tested ones seems to be polycaprolactone (PCL).

Development of Particleboard from Green Coconut Waste

In this study, green coconut waste was successfully transformed into coconut fibre-based particleboards. In addition to urea-formaldehyde (UF), two types of green binder: BST00 (low ammoniated latex and epoxidized natural rubber latex-based) and BST20 (epoxidized natural rubber latex-based) were used in particleboard fabrication. The particleboards were fabricated using coconut pith and fibre with 15% binder loading through two pre-compression steps followed by a final hot compression at 140 °C for 15 mins at ∼2.1 MPa. Board properties such as density, thickness swelling (TS), water absorption (WA), and internal bond (IB) strength were determined in accordance with JIS A 5908 standard, except for modulus of rupture (MOR) (ASTM D1037). BST00-bonded particleboards exhibit the poorest properties among the three samples, making BST00 the least effective binder. BST20-bonded particleboards show the best overall properties with the highest density of ∼1 g/cm3, IB value of 0.416 MPa, MOR of 11.61 MPa, best water resistance with TS of 14% and WA of 24%. The UF-bonded particleboards have the highest MOR of 12.05 MPa. Overall, the UF- and BST20-bonded coir particleboards met the minimum JIS A 5908 requirement except density (0.4-0.9 g/cm3) and TS (<12%). The green binder BST20 has shown great potential to replace UF.

Effects of Variety and Growing Location on Physicochemical Properties of Starch from Sweet Potato Root Tuber

Three sweet potato varieties with purple-, yellow-, and white-fleshed root tubers were planted in four growing locations. Starches were isolated from their root tubers, their physicochemical properties (size, iodine absorption, amylose content, crystalline structure, ordered degree, lamellar thickness, swelling power, water solubility, and pasting, thermal and digestion properties) were determined to investigate the effects of variety and growing location on starch properties in sweet potato. The results showed that granule size (D[4,3]) ranged from 12.1 to 18.2 μm, the iodine absorption parameters varied from 0.260 to 0.361 for OD620, from 0.243 to 0.326 for OD680 and from 1.128 to 1.252 for OD620/550, and amylose content varied from 16.4% to 21.2% among starches from three varieties and four growing locations. Starches exhibited C-type X-ray diffraction patterns, and had ordered degrees from 0.634 to 0.726 and lamellar thicknesses from 9.72 to 10.21 nm. Starches had significantly different swelling powers, water solubilities, pasting viscosities, and thermal properties. Native starches had rapidly digestible starch (RDS) from 2.2% to 10.9% and resistant starch (RS) from 58.2% to 89.1%, and gelatinized starches had RDS from 70.5% to 81.4% and RS from 10.8% to 23.3%. Two-way ANOVA analysis showed that starch physicochemical properties were affected significantly by variety, growing location, and their interaction in sweet potato.

Physico-Mechanical Properties of Particleboards Produced from Macadamia Nutshell and Gum Arabic

Due to the rising prices and high demand for panels and the fact that formaldehyde—a known carcinogen—is used to manufacture conventional particleboard, this study investigated the suitability of particleboard formed from ground macadamia nutshells mixed with 50%, 40%, 30%, and 20% of gum Arabic and determined its physical and mechanical properties. The specific gravity, the bulk density, the x-ray fluorescence, and the scanning electron microscopy analysis of the two materials were analyzed. After production, the particleboards were cured for 56 days in an acclimatized room; then, the physical and mechanical properties were evaluated. Particleboards mixed with 50% gum Arabic and 50% macadamia nutshell showed good results in terms of the lowest average values of water absorption (9.42%) and thickness swelling (6.22%) after 24 h of immersion in distilled water as well as the highest density (1219.20 kg/m3), modulus of rupture (12.21 MPa), modulus of elasticity (1.81 GPa), internal bond strength (1.25 MPa), and compressive strength (22.54 MPa). According to ANSI/A208.1-1999, the particleboards produced met the standard for general-purpose boards except for water absorption (WA) and thickness swelling (TS) characteristics, which were above the maximum of 8% and 3%, respectively.

Particleboards from Recycled Pallets

Worldwide production of wooden pallets continually increases, and therefore in future higher number of damaged pallets need to be recycled. One way to conveniently recycle pallets is their use for the production of particleboards (PBs). The 3-layer PBs, bonded with urea-formaldehyde (UF) resin, were prepared in laboratory conditions using particles from fresh spruce logs (FSL) and recycled spruce pallets (RSP) in mutual weight ratios of 100:0, 80:20, 50:50 and 0:100. Particles from RSP did not affect the moisture properties of PBs, i.e., the thickness swelling (TS) and water absorption (WA). The mechanical properties of PBs based on particles from RSP significantly worsened: the modulus of rupture (MOR) in bending from 14.6 MPa up to 10 MPa, the modulus of elasticity (MOE) in bending from 2616 MPa up to 2012 MPa, and the internal bond (IB) from 0.79 MPa up to 0.61 MPa. Particles from RSP had only a slight negative effect on the decay resistance of PBs to the brown-rot fungus Serpula lacrymans, while their presence in surfaces of PBs did not affect the growth activity of moulds at all.