The effects of hole size on open hole tensile properties of Kevlar-glass fibre hybrid composite laminates were thoroughly investigated in this work. Woven Kevlar/glass fibre epoxy composite laminates were fabricated using hand lay-up and vacuum bagging technique. Specimens of five different hole size (1 mm, 4 mm, 6 mm, 8 mm and 12 mm) were carefully prepared before the tensile test was performed according to ASTM D5766. Results indicated that hybridizing Kevlar to glass fibres improved tensile strength and failure strain of hybrid composite specimen. In addition, increasing the hole size reduced strength retention of the hybrid specimen from 96% for 1 mm hole size to 62% and 44% for 6 mm and 12 mm, respectively. Fractography analysis showed that several types of failure mechanisms were observed such as brittle failure, ductile failure, fibre breakage, delamination and fibre-matrix splitting. It is concluded that as hole size increased, failure behaviour changed from a matrix dominated failure mode to a fibre-dominated failure mode.
This paper investigates the effect of acid and silane treatment of Carbon Nanotubes (CNT) on wear properties of epoxy polymer composite. The wear test done was based on ASTM D3389 standard using the Abrasive Wear Tester (TR 600). Characterisation analysis was also done using Transmission Electron Microscopy (TEM) in order to study the dispersion of the CNT inside the epoxy matrix. When untreated CNT was added to the epoxy with amounts of 0.5, 0.75 and 1.0 wt%, the wear rates did not improve except for 0.5 wt% CNT filled epoxy. This was due to the lack of dispersion which causes larger chunks of material being dug out, thus contributing to a higher mass loss and wear rate. When treated with acid and silane, 0.75 wt% and 1.0 wt% CNT filled epoxy composites showed improvement. The TEM images of 0.5 wt%, 0.75 wt% and 1.0 wt% PCNT filled epoxy supported the claim of the lack of dispersion of PCNT inside the epoxy.
In recent years, injection moulding process is one of the most advanced and efficient manufacturing processes for mass production of plastic bottles. However, a good quality of parison is difficult to achieve due to uncontrollable humidity, pressure inlet and water inlet velocity. This paper investigates the effect of using multiple mould cavities to improve the process fill time and injection pressure in the production of PET plastic bottles using MoldFlow software. The modelling of parison was developed using CATIA with the consideration of every part of the parison. MoldFlow software was used to analyse the flow of 20 g parison with different cavity numbers (1, 8, 16, 24 cavity), as well as its corresponding runner size towards its fill time and injection pressure. Other important parameters that affect the production of parison, such as melting temperature, mould temperature, atmospheric temperature and cooling time, were remained constant. The fill time required to produce 24 moulds was improved by 60% compared to using 8 mould cavity only, and this enable the production of more plastic bottles in a day. Therefore, fill time and injection pressure are two important parameters to be considered in the injection moulding process, especially to reduce parison defect and increase its production rate.
This paper presents a study on the effect of Arenga Pinnata fibre volume fraction on the tensile and compressive properties of Arenga Pinnata fibre reinforced epoxy composite (APREC). The composites were produced using four different Arenga Pinnata fibre volume contents, which were 10vol%, 15vol%, 20vol%, and 25vol%, in unidirectional (UD) fibre alignment. Tensile and compression tests were performed on all APREC specimens in order to investigate the effect of fibre volume fraction on modulus of elasticity, strength and strain to failure. The morphological structure of fractured specimens was observed using scanning electron microscopy (SEM) in order to evaluate the fracture mechanisms involved when the specimens were subjected to tensile or compressive loading. The results indicated that the higher the amount of Arenga Pinnata fibres, the higher the stiffness of the composites. This is shown by the increment of tensile and compressive modulus of the specimens when the fibre volume content was increased. Tensile modulus increased up to 180% when 25vol% Arenga Pinnata fibre was used in APREC compared to Pure Epoxy specimen. It can also be observed that the tensile strength of the specimens increased 28% from 53.820 MPa (for Pure Epoxy) to 68.692 MPa (for Epoxy with 25vol% APREC addition). Meanwhile, compressive modulus and strength increased up to 3.24% and 9.17%, respectively. These results suggest that the addition of Arenga Pinnata fibres significantly improved the tensile and compressive properties of APREC.
This paper investigates the flexural properties of Arenga Pinnata fibre reinforced epoxy composite
(APREC) in relation to its fibre arrangement. The composites were produced using Arenga Pinnata fibre
as the reinforcement material and epoxy resin as the matrix. In this work, two types of Arenga Pinnata
fibre arrangement were under-studied, randomly distributed and unidirectional distributed (UD). Samples
were prepared at 10vol%, 15vol%, 20vol%, and 25vol% of fibres reinforcement to matrix ratio for both
types. Three-point bending configuration flexural tests were performed for both randomly distributed
APREC and UD APREC at 10vol%, 15vol%, 20vol%, and 25vol% respectively. Results indicated that
UD APREC have better flexure modulus and flexure strength for all the fibre loading percentages (vol%)
as compared against the randomly distributed APREC. The 25vol% UD APREC showed the highest
modulus (3.783 GPa) with an increment of 31.0% as compared against the pure epoxy (2.888 GPa).
It was also observed that there was no significant increment on flexure strength for both random and
unidirectional APREC as compared to pure epoxy (61.125 MPa), but the flexure strength value decreased
for randomly distributed fibre orientation for all fibre volume percentages (vol%)
In this study, oil palm fruit bunch fiber (OPEFB) was used as a secondary filler in HDPE/clay nanocomposites. The composites were prepared by melt compounding, containing high density polyethylene (HDPE), OPEFB fibers, Maleic anhydride grafted polyethylene (MAPE) and four different clay loading (3, 5, 7 and 10 PE nanoclay masterbatch pellets per hundred HDPE pellets). Four OPEFB sizes (180 μm, 250 μm, 300 μm and 355 μm) were added in the composites to investigate its effects on the fracture toughness and impact strength. Fracture toughness of the composites was determined according to ASTM D5045 and single edge notch bending (SENB) was employed during the test while impact tests were performed according to ASTM D256. The effects of alkali treatment were also investigated in this study. The result indicates that the fracture toughness slightly increased as clay loading increased. The highest value of fracture toughness was 0.47 and 1.06 MPa.m1/2 at 5 phr for both types of composites. The presence of OPEFB fiber as a secondary filler in the matrix indicates significant enhancement of fracture toughness up to 133%. However, its impact strength seems to deteriorate with the presence of OPEFB fiber.
The study aims to investigate the effect of injection moulding parameters on plastic flows behaviour of the multiple-cavity polyethylene terephthalate (PET) cylindrical containers via injection moulding process. The motivation of this study is to present an alternative manufacturing solution to make cylindrical type containers that are commonly used in packaging beverages, such as the 330 ml standard size for packaging carbonated soft drink. The PET cylindrical container was modelled using CATIA drawing software and the injection moulding simulation process was done via Moldflow software. The investigation was done by varying two significant moulding parameters; the material melt temperature and the mould temperature. The effects of these two parameters on the PET plastic flow behaviour were studied. In particular, the simulations of the model were analysed and focused on the mould filling time as well as the moulded PET cylindrical container’s shrinkage occurrence. Three types of mould cavities structure were understudied; single-cavity, four-cavity and eight-cavity. Results show that the eight-cavity mould yielded higher production rate. The simulation results indicated that the production rate of 4-cavity and 8-cavity mould increased by 258.5% and 578.8% respectively. It was observed by increasing the melting temperature, the mould filling time is shorter and as a result, the production rate has increased by 7.75% per °C. But with this Mouldflow setting, the volumetric shrinkage and the maximum deflection have been significantly affected; increased by 23.15% and 29.26% respectively. The mould filling time and maximum deflection did not show a steady trend line however, the volumetric shrinkage increased by 7.28% per °C.
This research investigated the wear properties of Carbon Nanotube (CNT) filled epoxy polymer and fiber reinforced composites. The CNT/epoxy composites with 0.5 wt% and 1.0 wt% CNT contents were mixed at 50°C for 1 hour at a speed of 400 rpm using mechanical mixer, while woven glass fiber reinforced polymer (GFRP) nanocomposites were fabricated using vacuum bagging technique. The effect of CNT on wear properties was evaluated using dry sliding abrasion wear test that used vitrified bonded silicon carbide as abrasive wheels. The mass loss and specific wear rate curves show that wear properties of epoxy polymer and GFRP composite systems were enhanced when CNT was added. Epoxy polymer and GFRP nanocomposites showed the highest wear resistance when CNT content was 1.0 wt% and 0.5 wt% respectively. The CNT-filled composite showed improvement till up to 78.9 % from its pure system. This suggested that the load transferability between CNT and epoxy was more effective in nanomodified systems than in its pure systems. Therefore, adding CNT improves the wear properties of epoxy polymer and woven GFRP composite.
In this paper, the wear properties of nano-filled Glass Fibre Reinforced Polymer (GFRP) composite are
studied based on the effects of the architecture of the glass fibre and test environment. Wear tests were
done under two different conditions; dry environment test and wet environment test. The dry and wet
environment tests were conducted using the abrasion resistance tester (TR600) and slurry erosion tester,
respectively; the slurry mixture of sand and water were used in the wet environment test. Two types of
glass fibres architecture were understudied; unidirectional and woven. It was found that 3 wt.% filler
content is the optimum amount to be used for the GFRP composite. Unidirectional nano-filled GFRP
composites exhibited the lowest wear rates due to their closely aligned glass fibre arrangement. The
unidirectional fibre alignment provided less empty spots for the interlocking process to take place, thus
reducing the ploughing action of wearing. However, when tested in the wet environment, effects of
other testing parameters such as the architecture of fibre and filler contents became less significant. The
composites, which were tested in wet environment, showed the lowest wear rates compared to the ones
tested in the dry environment. This is due to the presence of water that helps to wash away the pulverised
glass fibre, thus reducing the friction and the three-body wear effect