Hiroyuki Inoya

Study on the Effective of Utilization in Vent-Type Injection Molding

. In this study, characteristics of glass fiber reinforced recycled-PET composites by using direct fiber feeding injection molding (DFFIM) process were studied. The results, when varied processing conditions, indicated that decreasing of matrix feeding screw speed and increasing of number of glass fiber led to the increasing of fiber loading content, respectively. The average fiber length of glass fiber tended to decrease with the increasing of fiber loading content. Tensile modulus and tensile strength exhibited almost linear correlation with glass fiber load content. For study on stability of DFFIM process performance, at earliest stage of DFFIM process, discarding of at least five injected shots must be done in order to prepare the system availability of DFFIM process. The DFFIM machine could uninterruptedly manufacture composites without any problems occurred during 7 hours, which consequently provided high stability of product quality with long-term fabrication.

Optimizing of vented injection molding on mechanical performance and miscibility of recycled poly(ethylene terephthalate) and polycarbonate blends

Abstract Blending of recycled poly(ethylene terephthalate) (RPET) and polycarbonate (PC) was performed by melt compounding. The blends were subsequently fabricated to dumbbell specimens by vented injection molding. The mechanical properties, thermal characteristic and morphology of RPET/PC blends were investigated as a function of PC contents. Vented injection molding presented an advantage for superior mechanical properties of RPET/PC blends. The addition of PC enhanced impact strength and fracture toughness with remaining tensile properties. The glass transition temperatures of PET and PC shifted toward each other, which indicated their partial miscibility of RPET and PC in the blends. The toughness mechanism of RPET and PC was related to core-shell structure and good interfacial adhesion at higher contents of PC.

Development of Cotton Candy Method for High Productivity Polypropylene Fibers Webs

The cotton candy method (CoCAM) is developed for high productivity of polymer micro-and nano-fibers. Polypropylene was molten in a single screw extruder of the CoCAM at air pressures of 0.2-0.5 MPa with nozzle temperatures of 280-350 °C and the constant air temperature of 600 °C. The distance from the nozzle to the collector was set at 10-90 cm. Thermal images informed the accumulation of PP fibers flows at shorter collector distance. The diameters of PP micro-fibers decreased with increasing the air pressures and the nozzle temperatures. Crystallinity of the PP micro-fibers increased when increasing the nozzle temperature due to higher occasion of molecular orientation. The degree of the fiber entanglement in the PP micro-fibers decreased when increasing the collector distance, which affected on the declination of tensile strength. Ductility of the PP micro-fibers improved at high collector distances. The optimum condition of the PP micro-fibers was found at the average diameter of 2.3 μm at 0.5 MPa with the nozzle temperature of 340 oC collected at 60 cm. The productivity of the PP micro-fibers webs from the CoCAM was 144 g/h.

RETRACTED: Fabrication of Poly(Lactic Acid) Nanofibers by Cotton Candy Method

The poly (lactic acid) (PLA) fiber of biodegradable polymer was fabricated by cotton candy method with small nozzle. The air pressure was varied from 0.2-0.5 MPa with nozzle temperature of 210-260°C. The morphology of fiber was determined by scanning electron microscope (SEM). Thermal properties were examined using differential scanning calorimetry (DSC). SEM results suggested that diameters the PLA fiber at temperature 250°C and air pressure of 0.2 MPa were smaller than the fiber at low and high temperature. The sizes of the fibers were lower than 1 μm and the fibers were irregular size. Crystallinity significantly decreased when increasing barrel temperatures while it slightly changed when varied air pressure. The productivity of PLA fibers was around 30-180 g/h depended on controlled the nozzle temperature and the air pressure.

Effect of Scratch on the Mechanical Property of Injection Moldings

As well known that material’s scratch behavior/resistance is considering as a kind of surface toughness parameter, which can affect product’s appearance quality and mechanical property reduction. Material’s surface scratch damage may also accelerate critical fracture existence in following mechanical test process.In this paper, dumbbell and plate samples of neat polycarbonate (PC) and 20wt% of glass fiber (GF) additive corresponding GF/PC composite were fabricated by injection molding technology. Basically, scratch damage performance was investigated by applying various scratch depths in dumbbell sample thickness direction following with tensile property change discussion. Initially, cross-section of scratch path in samples was observed to investigate various scratch parameters’ effect on scratch damage. Afterwards, dumbbell tension, plate’s drop weight impact test and bending test were conducted. Finally, dumbbell sample tension’s brittle fracture and plate’s impact damage tolerance were discussed based on tension strain, impact energy absorption and fractural appearance. The results indicates that material’s critical scratch depth could make sample’s tension fracture change from ductile to brittle, affecting material’s failure early-warming. Additionally, PC material with surface damage would decrease the energy absorption during plate bending process bearing smaller maximum load and deflection.Copyright

Mechanical Properties of Glass Fiber Reinforced Polyoxymethylene Composites by Direct Fiber Feeding Injection Molding

In this study, the short glass fiber reinforced polyoxymethylene composites were fabricated by direct fiber feeding injection molding (DFFIM). The processing parameters such as number of fiber, matrix feeding speed and screw rotational speed are study the effect on fiber content, fiber length and mechanical properties. Fiber orientation and fiber distribution are observed by scanning electron microscope. The maximum and minimum fiber content are 34.1 and 11.5 wt.%, respectively. The increasing of number of fiber and screw rotational speed and the decreasing of matrix feeding speed lead to the increasing of fiber content. Tensile modulus increase when fiber content increase. However, tensile strength do not increase when fiber content is over 23.3 wt.% due to poor orientation and distribution of glass fiber.© 2014 ASME

Hydrothermal Aging and Mechanical Property of Injection Molded Jute/Glass/Polypropylene Hybrid Composites

As well known, the durability of the material is always considered in the safety design of the materials. Therefore in this study, the property of injection molded hybrid jute/glass reinforced polypropylene (PP) composites was firstly investigated after the hot water immersion experiment. The hydrothermal aging performance was investigated in the 80 °C hot water immersion experiment with a series of immersion time and different fraction of jute fiber and the effects of hot water immersion on the mechanical properties of composites have been evaluated based on the tensile test. Water absorption and weight loss of the reinforced PP composites were recorded and discussed. It is found that with the increase of jute fiber content, the tensile modulus is increased. However, the increasing of jute fiber content decreased the tensile strength of hybrid composites. For the effect of hydrothermal aging, the weight by water absorption was significantly affected by the jute fiber content. The specimens with higher jute fiber content absorbed water easier and significant materials loss by aging was also occurred. Tensile properties of hybrid composites which contain jute fiber showed the lower tensile strength than the monotonic glass/PP composite. It is considered that the hydrophilic property of jute fiber decreases the resistance of the hybrid composite in high humidity environment.Copyright