Lower Thickness Swelling Research Articles

Study of the production process of 3-layer sugarcane-bamboo-based particleboards

This study evaluated the technical viability and performance of two different production processes of 3-layer sugarcane-bamboo-based particleboard (3LP) (3LP-PL: pressing in each layer; and 3LP-NPL: non-pressing in each layer) throughout their thermal, physical, mechanical and microstructural properties. The thermal conductivity was determined according to the methodology established by ASTM-E1530: 2011. Physical and mechanical properties were evaluated following the ABNT NBR 14810:2013 Brazilian Standards recommendations. Microstructural properties of the 3LP studied was assessed by using the Micro-CT technique. Thermal conductivity values of both 3LP were lower than the value required by Brazilian Standards for wood-based particleboards. Physical results indicated that the non-pressing in each layer during the 3LP production resulted in less thickness swelling (TS) and water absorption (WA). Modulus of rupture (MOR) and modulus of elasticity (MOE) of the 3LP-NPL showed an increase of 38 and 29% compared to the 3LP-PL respectively. Additionally, an increase of 31% was found for the internal bond (IB) value of the 3LP-NPL compared to the 3LP-PL. Considering the results achieved for the 3-layer sugarcane-bamboo-based particleboard the non-pressing in each layer during production presented lower TS and WA values and higher MOR, MOE and IB values.

Comparison of the Properties of Fiberboard Composites with Bamboo Green, Wood, or their Combination as the Fibrous Raw Material

The potential of bamboo green (B), an abundant lignocellulosic residue from the bamboo processing industry, was evaluated to serve as an alternative fibrous raw material in the production of fiberboard. Urea-formaldehyde resin-bonded fiberboards were prepared from B, wood fiber (W), and a mixture of the two (BW). The board type depended on the mass fraction of B in fibrous raw materials (including B and W), which were 0%, 20%, 40%, 60%, 80%, and 100%. The analytical methods used to characterize fibers and fiberboards included X-ray diffraction, thermogravimetric analysis, dynamic mechanical analysis, contact angle analysis, physical-mechanical analysis, and scanning electron microscopy. Compared with W, B showed a higher crystallinity index and thermogravimetric stability, but lower surface hydrophilicity and weaker interactions with urea-formaldehyde resin. Compared with W fiberboards, B fiberboards possessed a lower interfacial adhesion but fibrous raw materials in B fiberboards were better dispersed; moreover, B fiberboard displayed a higher dynamic viscosity, thermogravimetric stability, surface wettability, water absorption, and flexural modulus, but lower thickness swelling and flexural strength. The fiberboards produced with BW had better performances than the fiberboards produced with B and W. The 40% B mass fraction resulted in BW fiberboards with the best physical-mechanical properties.

Effect of particle treatment and adhesive type on physical, mechanical, and durability properties of particleboard made from Sorghum Bagasse

Refers to chemical content of sweet sorghum stalk especially for Numbu varian, sorghum bagasse issuitable for materials of particleboard. The objective of the experiment was to evaluate of particle treatment on physichal, mechanical, and durability properties of particleboard made from sorghum bagasse. For particle treatment, Sorghum bagasse immersed in cold water and hot water for 24 and 1 hours respectively. Particleboards were produced in size 25 by 25 cm2 with thickness and density target of 0.8 cm and 0.7 g/cm3. Amount of 10% Urea formaldehyde (UF) and 7% isocyanat (MDI) adhesive level used for manufacturing of board. Particle and adhesive were blended with rotary blending. Afterward, it was placed into mat former with size of 25 by 25 cm2. Mat was pressed by hot press machine. The pressing was conducted on 130°C temperature for UF resin and 160°C for MDI resin, pressure of 25 kg/cm2 and pressing time for 10 minutes. The results showed that particle soaking in hot water produced of lower thickness swelling compared to untreated board. Similar trend also occuron particleboard whichwas bonded with MDI resin. MDI as exterior adhesive resulted good performance in dimensional stability of sorghum bagasse particleboard. For UF bonded particleboard, immersing in hot water resulted in the low MOR, MOE and IB parameter. It’s contrary with MDI bonded particleboard.

Investigating water absorption and thickness swelling tendencies of polymeric composite materials for external wall application in refrigerated vehicles

Replacing external metallic wall of refrigerated vehicles has been on the front burner in many published works as weight of the metallic insulated panel continues to pose a challenge on refrigeration unit and environment. As a follow-up to this problem statement, five (5) composite materials were fabricated as replacement options for metallic external sheet for refrigerated vehicles. The key study of this paper is to investigate the moisture absorption and thickness swelling tendencies of these composite specimens as these properties determine the suitability of these materials for refrigerated wall. Part of the methodology adopted in the manufacturing of these composites were based on fibre loading and orientation in the composite panel. Key findings from this experiment shows that the absorption behaviour of composites at 30 o and 60 o was consistent until 60 hours duration of immersion before a significant disparity was observed. In addition, G­ 30 E (30% reinforced glass fibre in the epoxy composite) was more resilient to moisture attack as a result of enhanced fiber content. The implication of the study is that G 30 E reinforced composite material could be adopted as external wall of food transport system because of its lower thickness swelling and water absorption properties. http://dx.doi.org/10.4314/njt.v37i1.22

Production and characterization of particleboards from cork-rich Quercus cerris bark

Single-layered particleboards were produced from granulated Quercus cerris bark containing cork and phloem granules using standard hot-press equipment and phenol–formaldehyde resin. The experimental boards were tested for thickness swelling, mechanical strength and thermal properties. Scanning electron microscopy observations were carried out to analyze the panel structure. The results showed that Q. cerris bark particleboards had low thickness swelling in water, high resistance to thermal degradation and high calorific values but their mechanical strength was below that of commercial wood particleboards. The produced Q. cerris bark particleboards were adequate for exterior applications where mechanical strength is not the key factor. Potential for process and feedstock optimization was acknowledged.

Selective Biodegradation of Grape Pomace Tannins by Aspergillus niger and Application in Wood Adhesive

The selective biodegradation of grape pomace tannins was studied using Aspergillus niger strains. The conditions were optimized in terms of monomeric catechin production. The optimal degradation conditions were: 10.0 g·L-1 of tannins in the induced medium, pH 6.5, and cultured on a shaking table at a rate of 120 r·min-1 at 28 °C for 36 h. The biodegraded tannins were used to partially substitute for phenol-formaldehyde in adhesive formulations. The biodegradation enabled the production of adhesives and wood panels with better properties (lower resin viscosity, higher internal bond strength, and lower thickness swelling). A particleboard in which the resin contained 60% biodegraded grape tannins displayed good performances (IBdry = 0.46 MPa, IBwet = 0.15 MPa) and passed the standard specifications for dry and wet conditions.

CHARACTERIZATION OF SELECTED PROPERTIES OF COMPOSITES OF WASTE PAPER WITH UNTREATED BAMBOO STEM FIBRE AND RICE HUSK

Composite technology is an excellent approach to utilizing natural fibres and agricultural wastes, which constitute an environmental nuisance. Efforts are being made to characterize the properties of composites produced from different sources of these wastes and fibres to facilitate a choice and selection for different applications. In this study, selected properties of composite samples, produced from waste paper in equal mix-ratio with rice husk and bamboo stem fibres (BSF) separately without chemical pre-treatment using cassava starch as a binder, were characterized. Composites from rice husk are better in terms of their higher compressive strength (71–202N/mm<sup>2</sup>), lower water absorption, at a rate of 1.97–5.19 and 1.09–3.02%/min, and a lower thickness swelling, at a rate of 0.74–1.23 and 0.52–0.70 %/min at 30 min and 1 h immersion time respectively, while that from the BSF is superior for its lower density 0.321–0.358 g/cm<sup>3</sup> and specific weight 3.15–3.51 kN/m<sup>3</sup>. The material composition (percentage fibre volume fraction) appears to have no significant effect on the impact strength 26.0–26.4 kJ/m<sup>2</sup> as well as other selected properties of the composites (p > 0.05). However, all the samples have properties that meet the requirement for composites except that the water absorption and thickness swelling are relatively high. The composites have considerably low density, which makes them suitable in light weight applications. Their compressive and impact strength make them appear specifically relevant for the production of construction blocks and industrial helmets respectively. Meanwhile, the properties are liable to modification with a chemical pre-treatment of the fibres.

Experimental study on waterproofing MDF with castor oil-based vegetal polyurethane

This study aimed to analyze the waterproofing MDF with different coatings. For this, a comparative study was conducted with the following coatings on MDF: Vegetable polyurethane resin on castor oil-based, acrylic lacquer and marine varnish. To carry out the research, sewed up the samples in sequence, they received the coatings, and then we performed the test water absorption. As a result, the polyurethane resin to castor oil-based coating was presented the best results, that is, lower levels of water absorption lower thickness swelling and volume. Finally, it is believed that the study of waterproofing MDF plant originated from polyurethane castor oil is beneficial because it is a renewable source of material.

HYDROTHERMAL TREATMENT OF OIL PALM WOOD: EFFECT OF TREATMENT VARIABLES ON DIMENSIONAL STABILITY USING RESPONSE SURFACE METHODOLOGY

Oil palm wood (OPW) extracted from felled oil palm trunks during replanting could be a source of replenishment for the depleted timber sources. Nevertheless, dimensional instability of OPW is one of the drawbacks that need to be addressed before it can be utilised efficiently. Therefore, to improve its dimensional stability, hydrothermal treatment using different buffered media was employed in this study and the optimal treatment condition for OPW were investigated. Response surface methodology (RSM) models for treatment temperature, treatment duration and buffered media of hydrothermally treated OPW were developed. OPW samples were hydrothermally treated with different buffered media (pH 4 to pH 9), treatment temperature (60oC to 160oC) and time (13 min to 147 min). Water absorption (WA) and thickness swelling (TS) of the treated samples were determined. It is demonstrated that hydrothermal treatment has improved the dimensional stability of treated samples with treatment temperature appearing to be the most influential factor. Samples treated in an acidic media displayed lower WA mainly due to the fact that higher amount of hydrophilic hemicellulose was degraded under acidic condition. However, lower TS was observed in the samples treated in alkaline media, probably caused by the removal of lignin that increased the porosity of the OPW.

The influence of raw material growth region, anatomical structure and chemical composition of wood on the quality properties of particleboards

In the present study, the impact of raw material grown region on the physical, mechanical, surface properties and formaldehyde emission of the particleboard was investigated. Ailanthus altissima wood grown in Trabzon had longer fiber length and thicker fiber and trachea cell wall than those of the wood grown in Artvin. The highest amounts of lignin, ash, condensed tannin and solubility values were found in wood grown in Artvin. Ailanthus altissima wood grown in Trabzon had higher amounts of cellulose and hemicellulose than those of the wood grown in Artvin. Particleboards made from wood grown in Artvin had worse surface quality and mechanical strength properties than those of panels made from wood grown in Trabzon. On the other hand, the results showed that particleboards produced from wood grown in Artvin had lower thickness swelling and formaldehyde emision values than those of the panels produced from wood grown in Trabzon.

Bonding of recycled fibres with urea-formaldehyde resins

The work aimed to study the influence of replacing virgin wood fibres by recycled fibres, made from recovered medium-density fibreboards (MDF) by thermo-mechanical pulping, on the physical-mechanical properties and formaldehyde release of urea-formaldehyde (UF)-bonded MDF. It was found that replacement of 33% virgin fibres by recycled fibres decreased significantly the thickness swelling and water absorption of the UF-bonded MDF and mitigated the formaldehyde release. However, supplanting 33% of virgin fibres by recycled fibres had a negative impact on the internal bond strength. UF-bonded MDF with higher amounts of recycled fibres (67 and 100%) could not be produced without applying the hybrid bonding technology, i.e. adding small quantities of polymeric diphenylmethane diisocyanate to the UF resin. MDF made from 100% recycled fibres showed significantly lower thickness swelling values as well as a drastic drop in the formaldehyde release compared with boards made from virgin wood fibres.

Effect of Wood Shaving to Improve the Properties of Particleboard Made from Sorghum Bagasse

The objective of this research was to evaluate the effect of wood shaving added to improve the mechanical properties of particleboard. Wood types were using in this research included of Meranti, Cempedak, Mahagony, and Durian wood. Ratio of Sorghum bagasse and wood shaving was 50/50 (%w/w). Amount of 10% urea formaldehyde (UF) resin used for binding in the manufacturing process. Furthermore, hot pressing of mat at 130°C temperature for 10 minute and 30 kg cm-2 pressure. The final step was conditioning process for 7 days at room temperature before testing of sample. The results showed that the thickness swelling (TS) parameter did not met of JIS A 5908 (2003). Overall the present of wood shaving resulted in decreasing of TS value. Combination of Cempedak and Mahagony wood resulted of the lower TS value compared with control and other treatment. For bending properties, combination of sorghum bagasse and Cempedak wood shaving resulted the best of bending properties. However for the MOE parameter had not met JIS A 5908 (2003). The internal bond (IB) parameter showed that the utilization of wood shaving to produce of particleboard caused of increasing the IB value. The IB value was resulting from this research had met of JIS A 5908 (2003).

Functionally Graded MDP Panels Using Bamboo Particles

MDP (medium density particleboard) panels are normally graded in composition along their cross-section, using low-size particles and high concentration of adhesive on the particleboard surface (leading to improved physical and mechanical properties), and high-size particles in the particleboard core (interior), which provide higher porosity. Then, the aim of this study was to evaluate the impact of using different contents of bamboo particles in the particleboard core, on their physical and mechanical properties. The production of the panels was carried out using Pinusoocarpa (P) and Bambusavulgaris var. Vittata (B) particles in different contents (100% P, 100% B, 50% de B e 50% de P, 25% de B e 75% de P, 75% de B e 25% de P) in the core of the particleboards. The face of the particleboards were composed of P particles. The panels were produced with nominal density of 0.70 g/cm3, 40:60 face:core relation, 11% urea-formaldehyde adhesive in the faces and 8% adhesive for the core, specific pressure of 3.92 MPa, 160 °C temperature and pressing time of 8 min. After seasoning, the panels were submitted to evaluation of the thickness swelling (TS) and water absorption (WA) after 2 and 24 h of immersion, apparent density (AD), internal bonding (IB), modulus of rupture (MOR) and modulus of elasticity (MOE) under static bending. There was no statistical difference between the treatments for AD, IB, MOR and MOE values. Panels produced with high contents of bamboo particles (100% B, 75% B e 50% B) in the core, presented the lower WA and TS values, leading to improved dimensional stability than panels with only pinus particles. The present results show the important impact of using functionally gradation and bamboo particles on the physical properties of the MDP panels produced.

Bi-Sn 용융합금주입 목재복합체의 최적제조조건 및 물리·기계적 특성

ABSTRACT In order to improve the dimensional stability and durability of wood, this study attempted to impregnate bismuth (Bi) - tin (Sn) alloy metal with low melting temperature into solid woods of three species such as radiata pine, redoak and white oak, and investigated to determine an optimum condition of manufacturing the metal alloy-wood compo-sites with natural wood grains. These Bi-Sn alloys were chosen for this study because they were harmless to human and melting at low temperatures. The composites resulted in high dimensional stability and low thickness swelling, and also showed much improved performance such as high bending strength, high hardness, high electric conductivity, andhigh thermal conductivity as floor materials. A proper impregnating condition of all specimens was determined as 10minutes of the preliminary vacuum time, and 185℃ of the heating temperature. The proper processing condition forradiata pine wood was 2.5 minutes of the pressuring time at the pressure of 10 kgf/cm

Medium Density Fibreboard Made from Kenaf (Hibiscus cannabinus L.) Stem: Effect of Thermo-mechanical Refining and Resin Content

The present study deals with the physical and mechanical properties of dry-formed medium density fibreboard (MDF) made from renewable biomass kenaf (Hibiscus cannabinus L.) stem as a function of adhesive level and refining conditions. Raw material was prepared by heating for 5 min at pressure levels of 6 and 8 bars. Experimental samples with a target density of 700 kgm-3 were produced with 10, 12, or 14% urea formaldehyde as a binder. Physical properties of MDF panels, such as thickness swelling (TS) and water absorption (WA) as well as mechanical properties including modulus of rupture (MOR), modulus of elasticity (MOE), and internal bonding (IB), were evaluated. Based on the test results, resin content and refining pressure have significant effects on the physical and mechanical properties of MDF panels. High resin content and pressure produced MDF boards with low WA and TS but high MOR, MOE, and IB. At 8 bars pressure and 14% resin content, the MDF recorded optimum WA (83.12%), TS (20.2%), MOR (25.3 MPa), MOE (3450 MPa), and IB (0.51 MPa).

The Improvement in Physical and Static Bending Properties of Woven Oil Palm Plywood

The physical and static bending properties of woven oil palm plywood pre-treated with low molecular weight of phenol formaldehyde (LMWPF) were investigated using MS standard 1787: Part 6 and 10. The oil palm veneers were cut into three different split widths of 15, 20 and 25 mm; and manually woven into veneer sized of 40 cm2. The plywoods were fabricated into three different matrix layers of Type 1 (all three layer contained woven veneers), Type 2 (only core layer contained woven veneer) and Type 3 (face and back layers contained woven veneer). All plywood were made using a urea formaldehyde resin (UF) with spread rate of 200g/m2, pre-pressed for two minutes and hot pressed at 130 °C for 12 minutes. The results revealed that Type 1 plywood gave the lowest thickness swelling, while Type 3 gave the highest static bending properties.

The suitable harvesting season and the part of moso bamboo (Phyllostachys pubescens) for producing binderless boards

The properties of the binderless boards of moso bamboo depending on the harvest seasons and the parts of the height were reported and the optimum harvesting conditions investigated. The binderless boards were prepared from the powdered bamboo harvested each month from June to May, and the parts in height. The hot water extract (HWE), lignin, α-cellulose, and hemicelluloses contents were examined. The board properties were evaluated with internal bonding (IB), water absorption (WA), and thickness swelling (TS). From the experiment, the boards prepared between March and October had higher HWE content and higher IB and lower WA and TS than the ones prepared in other months. The board from the top part showed lower IB and higher WA and TS than the bottom and the middle. The boards prepared from the residue after extraction of HWE showed lower IB than the unextracted samples. These results indicated that for producing board from bamboo, the suitable harvesting season is when HWE contents are higher and that the suitable parts in height for harvesting are the bottom and the middle where lignin contents are not low.

The lamination influence on properties of agro-based particleboard

Response surface methodology (RSM) based on a three-level, three-variable central composite rotatable design was applied to evaluate the effects of the parameters such as ratio of rice straw (Oryza sativa)/poplar (Populus deltoids) wood particle bonded with urea-formaldehyde resin in panels, species of wood veneer coating these panels and amount of adhesive in glue line on the modulus of rupture (MOR), internal bonding (IB), and thickness swelling (TS) of panels. Mathematical model equations were derived by computer simulation programming to optimize the properties of the particleboard. These equations that are second-order response functions representing MOR, IB, and TS were expressed as functions of three operating parameters of panel properties. Predicted values were found to be in a good agreement with experimental values (R 2 values of 0.96, 0.98 and 0.98 for MOR, IB, and TS, respectively). This study has shown that the RSM could efficiently be applied for modeling panel properties. It was found that the variables affected the properties of panels. Straw usage up to 30% in the mixture did not cause a significant decrease in MOR, IB, and TS. Using beech veneer and 190 g/m2 glue line had the highest MOR and lowest TS.

Particleboard from waste tea leaves and wood particles

The study investigated the use of waste tea ( Camellia sinensis) leaves mixed in various proportions with Paraserianthes falcataria (moluccan sau) wood particles for the manufacture of particleboard. Boards containing waste tea leaves alone showed low thickness swelling and water absorption after 24 h soaking in water. Addition of P. falcataria wood particles from 20% to 50% to waste tea leaves resulted in boards with satisfactory thickness swelling, water absorption, internal bond, stiffness, and strength well above the minimum requirements for general use particleboards set by EN 312-2 (1996). Results of the study showed that waste tea leaves can be used as an alternative material either alone or in combination with wood particles for the manufacture of particleboard.

Evaluation of the Properties of Particleboard Made Using Oil Palm Starch Modified with Epichlorohydrin

The objective of this study was to investigate the physical properties, including density, moisture content, thickness swelling, and water absorption, in addition to the mechanical properties such as modulus of rupture, modulus of elasticity, and internal bond strength of experimental panels that were made from rubberwood particles using oil palm starch modified with epichlorohydrin as a binder. The samples were also examined using X-ray diffractometry, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. The panel properties were compared with the properties of panels manufactured using native oil palm starch. The properties of starch and starch adhesives were also investigated. The panels were produced based on 0.60 g/cm3 and 0.80 g/cm3 target densities and two press times of 15 and 20 min. The results showed that the 0.80 g/cm3 panels manufactured using modified oil palm starch and with 15 min of press time had better properties than did the others. However, a lower thickness swelling value was found for panels with density 0.60 g/cm3 and with 15 min of press time. Based on the results in this study, it can be concluded that the use of oil palm starch modified with epichlorohydrin as a binder has the potential to be used as a green adhesive in commercial applications.