Validation of finite element analysis for a new external finger fixator to correct flexion deformity - a preliminary result

The purpose of this study is to validate of a new external finger fixator components by using finite element analysis (FEA). The new external finger fixator consists of proximal, middle and distal phalanges support sections and means for rigidly connecting each support to a hinge and its corresponding attached to phalanx through the movements of flexion or extension. The results from the analysis found that the entire components of the fixator conform to the performance based on the requirements for general duty (500 N load applied on uniformly distributed load). This analysis shows that the new external fixator is able to restore full function and dynamic range of motion for patients with flexion deformity at the finger joints without failure

Response Surface Methodology Models of Processing Parameters for High Performance Phenolic Compreg Wood

The aim of the study was to develop response surface methodology (RSM) models for polymer loading, density, dimensional stability, strength and stiffness of compressed wood of sesenduk (Endospermum diadenum) treated with phenol formaldehyde (PF). Central composite design (CCD) using RSM with three processing parameters was studied in their specific ranges: PF concentration (PC) from 24-40%, pre-curing time (PCT), 3-9 h and compression ratio (CR), 70-90%. The experimental design was analysed and interpreted using the Design Expert Software (Stat Ease version 8) and the responses of 3d plots were built using the same software. Quadratic models in terms of PC, PCT and CR were developed for polymer loading, density, reduction in water absorption and modulus of rupture in static bending. Multiple linear equations were developed for anti-swelling efficiency and modulus of elasticity. The experimental values were in good agreement with predicted ones and the models were highly significant with correlation coefficients between 0.626 and 0.926. PC and CR had significant effects on the responses. The range of PCT used did not significantly affect the responses. It was also found that the improvement of properties ranged from moderately to highly correlated with the polymer loading in the compreg wood

Impregnation of sesenduk (Endospermum diadenum) wood with phenol formaldehyde and nanoclay admixture: effect on fungal decay and termites attack

The aimed of this study was to evaluate the resistance of sesenduk (Endospermum diadenum) wood, treated using admixture of low molecular weight phenol formaldehyde (LmwPF) resin and nanoclay, against white rot fungus (Pycnoporus sanguineus) and subterranean termites (Coptotermes curvignathus Holmgren). Seven sample groups including untreated sesenduk wood and treated sesenduk wood using 10, 15 and 20% LmwPF resin and the admixture of the 1.5% nanoclay with every level of resin concentrations. Air-dried samples were impregnated using vacuum-pressure process. After impregnation, the treated samples were heated in an oven at 150° C for 30 min. Five test blocks from each treatment group were tested separately against P. sanguineus and C. curvignathus in accordance with AWPA E10-12 and AWPA E1-13 standards, respectively. The results showed that both treatments had significant effects on the percentage weight loss and decay rate of the samples. The weight loss due to termite attack was found reduce with the increasing PF concentration. Generally, the addition of 1.5% nanoclay in PF resin slightly increased the resistance against both deteriorating agents compared to the wood treated using PF alone. It was found that the PF resin can be used as an effective method to improve the durability of sesenduk wood

Possibility of improving the properties of Mahang Wood (Macaranga sp.)through phenolic compreg technique

Lesser known wood species (LKS) have the potentials to become alternative sources of timber supply for wood based industries if their properties can be improved. In this study, Mahang wood (Macaranga sp.) was impregnated 15% (w/v) low molecular weight phenol formaldehyde (LMWPF) followed by compressing in a hot press at 70, 60 and 50% compression ratios (CR). The treated wood was partially dried in an oven at 65°C until 10% moisture content and subsequently followed by curing at 150°C for 30 min in a hot press. The results showed that the phenolic compreg technique had successfully increased the dimensional stability and mechanical properties of the wood. The polymer retention calculated based on weight gain regardless of compression ratio was approximately 30%. The majority of the properties were improved by the degree of compression in a hot press. Nevertheless, thickness swelling and swelling coefficient increased which were due to spring back effect. As regards to specific strength (strength to density ratio), the compreg wood displayed lower strength and stiffness in lateral direction compared with untreated solid wood. However, the specific compressive strength perpendicular to grain and hardness of the compreg wood were superior than untreated solid wood. The treatment had also changed the wood into highly resistant to fungal decay

Validation of finite element analysis for a new external finger fixator to Correct flexion deformity – a preliminary result

The purpose of this study is to validate of a new external finger fixator components by using finite element analysis (FEA). The new external finger fixator consists of proximal, middle and distal phalanges support sections and means for rigidly connecting each support to a hinge and its corresponding attached to phalanx through the movements of flexion or extension. The results from the analysis found that the entire components of the fixator conform to the performance based on the requirements for general duty (500 N load applied on uniformly distributed load). This analysis shows that the new external fixator is able to restore full function and dynamic range of motion for patients with flexion deformity at the finger joints without failure