Effects of Coating on the Dimensional Stability of Wood-Polymer Composites

Wood polymer composites (WPC) are sensitive to moisture because of the hydrophilic nature of the wood fibers. The main objective of this study was to improve the dimensional stability of WPCs by coating. Polypropylene and polylactic acid were reinforced by three pulp fibers (kraft, thermomechanical (TMP), and chemothermomechanical (CTMP)) at three fiber contents (50, 60, and 70% w/w). The resulting WPCs were coated using two commercial coatings, epoxy and acrylic. Kraft fiber WPCs were less sensitive to moisture than TMP and CTMP WPCs. These differences were explained by the crystallinity of the kraft fibers and their better interfacial adhesion to the polymers. The epoxy coating proved to be more effective than the acrylic coating and significantly reduced the water absorption and the thickness swell for all formulations. Negative relationships between the contact angle and water absorption were obtained. These relationships depend on the fiber content and type, the matrix nature, and the coating.

Effect of filler carbonization on agro-waste based ceiling board

This work presents the use as a filler of carbonized breadfruit seed coat and recycled low density polyethylene as the binder in ceiling board manufacturing. The depulped bread fruit seed was carbonized for 2 h at a temperature of 500°C. The experimental design was set up using the Design Expert software. A total of 30 experimental tests were developed for four parameters and three responses. The parameters are carbonized bread fruit seed coat/recycled Low Density Polyethylene mass ratio (filler-binder mass ratio), compaction time, compaction temperature and compaction pressure while the responses are thermal conductivity, thickness swell and water absorption. The models developed have been validated using the Study of Variance (ANOVA). Using the 3D surface map, the influence of the parameters on the responses was studied. The optimization method of the Design Expert program was used to evaluate the optimal level of the parameters that will produce the best possible result from their combination. The result gave optimal values of 16.206% filler/rLDPE, 9.406minutes compaction time, 200°C compaction temperature and 11 MPa compaction pressure, which gave 0.246% Water Absorption, 1.998% Thickness Swell and 2.898 W/M.K Thermal Conductivity.

Utilization of Ground Peanut Husk as an Alternative Fiber Material for Particleboard

The potential for using peanut (Arachis hypogaea) husks as an alternative fiber for particleboard production was examined at five different levels of melamine-urea-formaldehyde resin (MUF). The resulting panels were evaluated for moisture absorption, thickness swell, flexural properties (modulus of rupture [MOR] and modulus of elasticity [MOE]) and internal bond (IB) strength. MOR, MOE and IB values of panels containing ≥6 percent resin met or exceeded American National Standards Institute standards for multiple grades of particleboard although they were weaker than previous reports of commercially produced wood particleboards. Moisture uptake and thickness swell also improved markedly at resin levels >6 percent. The results suggest that peanut husks are an attractive alternative fiber source in combination with the MUF resin system.

Mechanical and Physical Properties of Particleboard from Untreated and Treated Kenaf Particles

Composite panels were manufactured from kenaf particles and treated with two different alkali treatments using 2% NaOH and 2% KOH with resin contents of 8% and 10% of phenol formaldehyde (PF) at medium density of 650kg/m3. The objectives of this study were to determine the mechanical properties in terms of its modulus of rupture (MOR), modulus of elasticity (MOE) and internal bond (IB), and physical properties namely thickness swelling (TS) and water absorption (WA) of treated kenaf board. The mechanical and physical tests were performed according to the Malaysian Standard (MS1787:2004). The minimum requirements value for MOE, MOR and IB were 2000 MPa, 14 MPa and 0.45 MPa respectively for furniture grade particleboards for use in humid conditions (PF2). According to Malaysian specifications for physical properties, the maximum requirement for thickness swell is 15%. Results indicated that both treated boards with NaOH and KOH showed an increase in strength properties compared to untreated particleboard. Particleboard treated with KOH exhibited the highest MOR and MOE values, while board with NaOH treatment gave the highest IB value. The boards with treated particles gave better performance in terms of physical properties. There were no significant differences in mechanical properties (MOR, MOE and IB) and physical properties for the different alkali treatment. The values of bending strength and IB strength increased with an increase in resin content, while TS and WA increased with a decrease in resin content. In conclusion, NaOH and KOH treated kenaf particles improved board performance and could be considered as an alternative material for particleboard production.

PENGUJIAN KUALITAS KAYU LAPIS UNTUK KONTRUKSI BANGUNAN YANG BEREDAR DI PASARAN KOTA BENGKALIS

Plywood is a composite product in form of an artificial board made of veneer sheets that were bonded together with an arrangement of perpendicular intersection. The quality of plywood circulating in Bengkalis City market was examined onits quality of the surface, inside and back space, moisture content and the thickness of its swell . The examination on the quality of plywood for construction of buildings circulating in Bengkalis City Market was using the standard of SNI 01-5008.2-1999. The test results of 4 plywood trademarks circulating in the market of Bengkalis City on its surface quality was showing that the product as known as Arwana and Tunas trademarks were belong to C class, Fortune that has quality B class, and OFR was on A class quality. While the quality inside of plywood of brand mark as Arwana, Tunas and Fortune were including to class A quality (overlap defect), but those 2 natural and technical defects is not including to SNI requirement criterias (slit and length), OFR trademark plywood’s inside quality was included into A classon its natural and technical defect criteria. Further, the quality of plywood’s back space of those 4 trademarks circulating in Bengkalis City were included into the standard SNI 01-5008.2-1999. The examintaion of moisture content in accordance to SNI 01-5008.2-1999 standard showed that Fortune and OFR trademark were fulfilling the requirement standard of 14%, while Arwana and Tunas were having higher water content (≥ 20%). At last, the thickness swell of all trademarks were in conformity with the SNI 01-5008.2-1999, in which reqiuring its thickness of 12%.

Study on the Fire Retardant Treatment Technologies of Bamboo Particleboard

This paper presents a study on the different fire retardant treatment technologies influence on the physical and mechanical properties of bamboo particleboard. The results showed: the properties of bamboo particleboard would change with changing of fire retardant treatment technology; among them the treated technology of fire retardant spraying after resin blending had larger changed; compared with non-fire retardant bamboo particleboard, the density and moisture content (MC) and 2h thickness swell (2h TS) of fire retardant bamboo particleboard had a little improved, and their internal bond (IB) and modulus of rupture (MOR) and modulus of elasticity (MOE) had slightly reduced.

Within-process and seasonal changes during industrial production of high-density fibreboard. Part 2: PLS modelling of chemical alterations, refining conditions and panel thickness swell

Wood species, carbohydrate composition and the content of extractives were determined from extracted wood chips and refiner fibres over 1 year of sampling at an industrial high-density fibreboard (HDF) plant. Correlations were found among processing variables (discharge screw flow, digester and refiner pressure, and refiner power consumption) and the analysed composition of raw materials and semi-finished product based on partial least squares regression (PLSR) analysis. Moreover, correlations between the degree of hemicellulose degradation and process variables were found. Panel thickness swell (PTS) was found to be affected by several raw and fibre material characteristics (based on PLSR), in which PTS was lower in the case of good fibre quality. These results demonstrate the potential impact of variable raw material properties on product properties and processing conditions in an industrial environment.