Now showing 1 - 3 of 3
  • Publication
    An investigation of the processability of natural fibre reinforced polymer composites on shallow and flat thin-walled parts by injection moulding process
    ( 2013) ;
    S.M. Sapuan
    ;
    S. Sulaiman
    ;
    E.S. Zainudin
    ;
    K. Abdan
    Currently, many industries are trending towards producing products exhibit such properties as small thickness, lightweight, small dimensions, and environmental friendliness. In this project, flat or shallow thin-walled parts were designed to compare the advantages and disadvantages of lignocellulosic polymer composites (PP + 50 wt% wood) in terms of processability. This study focused on the filling, in-cavity residual stresses and warpage parameters associated with both types of thin-walled moulded parts. Thin-walled parts 0.7 mm in thickness were suitably moulded using lignocellulosic composite materials to determine the effects of filling. The analysis showed, the shallow thin-walled part is preferable in moulding lignocellulosic polymer composite material due to the low residual stress and warpage measured. The results also indicate that the shallow thin-walled part is structurally rigid, such that it can be used in applications involving small shell parts, and can be processed more economically using less material than the flat thin-walled part.
  • Publication
    Energy behavior assessment of rice husk fibres reinforced polymer composite
    (Elsevier, 2020)
    S.A.N. Mohamed
    ;
    E.S. Zainudin
    ;
    S.M. Sapuan
    ;
    ;
    A.M.T. Arifin
    Natural fibre composites, possess characteristics that are beneficial towards the environment and ecosystem, completely biodegradable, renewable, offer strength and reliability of the material properties, and enhance economic development because of its ability in replacing synthetic composites. One of them refers to rice husk, which is a non-timber source that is easily available from agricultural wastes. Hence, rice husk fibres were selected as fibre-reinforced composites, while polypropylene as matrices in this research. Rice husk composite (RHC) specimens were produced via injection molding process. The composite composition was fixed at 35% of fibre content. The cycle tests were conducted to obtain cyclic properties by adhering to specifications outlined in ASTM D3479. Servo-hydraulic machines were used for five different stresses with constant amplitudes of R = 0.1, R = 0.3, and R = 0.5 of S75, S80, S85, S90, and S95 to determine the stress effects on energy dissipation and fatigue life of the material. The results indicated that there was increment in energy loss for the increasing fatigue life in every cycle. This shows that with the addition of natural fibres in composites, the material exhibited viscoelastic behaviour, in which energy loss was represented by matrix cracks and broken fibres.
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  • Publication
    Shrinkages and warpage in the processability of wood-filled polypropylene composite thin-walled parts formed by injection molding
    ( 2013-07-01) ;
    S.M. Sapuan
    ;
    S. Sulaiman
    ;
    E.S. Zainudin
    ;
    A. Khalina
    Reducing volumetric shrinkages and warpage during the injection molding process is a challenging problem in the production of molded thin-walled parts. In this study, the injection molding of shallow, thinwalled parts (thickness 0.7 mm), composed of lignocellulosic polymer composites (polypropylene (PP) + 50 wt% wood), was simulated. The volumetric shrinkages and warpage in the thin-walled parts were evaluated under different process conditions, with varying post-filling parameters, such as mold temperature, cooling time, packing pressure and packing time. The analysis showed that the cooling time and packing time had less of an effect on the shrinkage and warpage; nevertheless the optimal levels for both parameters are required in the molding process for the thin-walled part to achieve the best results. The volumetric shrinkage was lower near the gate than at the end-of-fill location along the flow path. The results also showed that the volumetric shrinkage correlates with the warpage measured on the molded part. The optimum parameters ranges is 40–45 C for the mold temperature; 20–30 s for cooling time; 0.85 from injection pressure (Pinject) for packing pressure; and 15–20 s for the packing time to achieve the best results with the least amount of volumetric shrinkage and warpage.
      3  24