• Preventive Nutrition and Food Science
• /
• v.17 no.3
• /
• pp.203-209
• /
• 2012

The effects of variable moisture content, screw speed and barrel temperature on the physicochemical properties of red ginseng powder extrudates were investigated. The raw red ginseng powders were processed in a co-rotating intermeshing twin-screw extruder. Primary extrusion variables were feed moisture content (20 and 30%), screw speed (200 and 250 rpm) and barrel temperature (115 and $130^{\circ}C$). Extruded red ginseng showed higher crude saponin contents (6.72~7.18%) than raw red ginseng (5.50%). Tested extrusion conditions did not significantly affect the crude saponin content of extrudates. Increased feed moisture content resulted in increased bulk density, specific length, water absorption index (WAI), breaking strength, elastic modulus and crude protein content and decreased water solubility index (WSI) and expansion (p<0.05). Increased barrel temperature resulted in increased total sugar content, but decreased reducing sugar content in the extrudate (p<0.05). Furthermore, increased barrel temperature resulted in increased amino acid content and specific length and decreased expansion and bulk density of extrudates only at a higher feed moisture content. The physicochemical properties of extrudates were mainly dependent on the feed moisture content and barrel temperature, whereas the screw speed showed a lesser effect. These results will be used to help define optimized process conditions for controlling and predicting qualities and characteristics of extruded red ginseng.

• Journal of Powder Materials
• /
• v.10 no.5
• /
• pp.325-332
• /
• 2003

The effect of extrusion temperature on the microstructure and mechanical properties was studied in gas atomized TEX>$Al_{81}Si_{19}$ alloy powders and their extruded bars using SEM, tensile testing and wear testing. The Si particle size of He-gas atomized powder was about 200-800 nm. Each microstructure of the extruded bars with extrusion temperature (400, 450 and 50$0^{\circ}C$) showed a homogeneous distribution of primary Si and eutectic Si particles embedded in the Al matrix and the particle size varied from 0.1 to 5.5 ${\mu}m$. With increasing extrusion temperature from 40$0^{\circ}C$ to 50$0^{\circ}C$, the ultimate tensile strength (UTS) decreased from 282 to 236 ㎫ at 300 K and the specific wear increased at all sliding speeds due to the coarse microstructure. The fracture behavior of failure in tension testing and wear testing was also studied. The UTS of extrudate at 40$0^{\circ}C$ higher than that of 50$0^{\circ}C$ because more fine Si particles in Al matrix of extrudate at 40$0^{\circ}C$ prevented crack to propagate.

• Transactions of Materials Processing
• /
• v.14 no.3 s.75
• /
• pp.233-238
• /
• 2005

Blow molding is divided into three categories, injection stretch blow molding, injection blow molding, and extrusion or direct blow molding. Extrusion blow molding has been studied experimentally to characterize the blowing behavior of parison. Blow conditions such as blowing temperature and cooling time were the experimental variables in this blowing experiment. Wall thickness of the lower part of blow molded sample was thicker than that of the upper part because of the sagging of parison during extrusion process. As temperature increases the wall thickness and the weight of blow molded sample decreased. No thickness variations in the blowing sample were observed according to the cooling time. The lower part of the sample showed high degree of crystallinity compare with the upper part of the sample. Thus the lower part of the sample was strong mechanically and structurally. It was recognized that the uniform wall thickness could not be obtained by only controlling the operational conditions. Parison variator should be introduced to get uniform wall thickness of parison and subsequently produce uniform wall thickness of blow molded product.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.311-318
• /
• 2001

A three-dimensional numerical analysis of the flow and heat transfer characteristic of wood-flour-filled polypropylene melt in an extrusion die was carried out Used for this analysis were Finite Concept Method based on FVM, unstructured grid and non-Newtonian fluid viscosity model. Temperature and flow fields are closely coupled through temperature dependent viscosity and viscous dissipation. With large Peclet, Nahme, Brinkman numbers, viscous heating caused high temperature belt near die housing, Changing taper plate thickness and examining some predefined parameters at die exit investigated the effect of taper plate on velocity and temperature uniformities. In the presence of taper plate, uniformity at die exit could be improved and there existed an optimum thickness to maximize it.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.17 no.7 s.94
• /
• pp.1740-1750
• /
• 1993

The aluminar short fiber reinforced composite materials for hot extrusion were fabricated by semi-solid stirring method, and extruded at extrusion temperature $400^{\circ}C$ with various extrusion ratio. The hot extrusion load of volume fraction 15% metal matrix composites and base alloy Al7075 has been compared. The fiber length distribution, fiber breakage and fiber orientation are investiged to know the fiber behaviour in before and after hot extrusion. The tensile strength of the hot extruded billet are experimentally determined for different of extrusion ratios, and compared with theorically calculated strength.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.10a
• /
• pp.70-73
• /
• 2007

The forming characteristics of cup-rod combined extrusion process were investigated with process parameter change. Simultaneous forward rod extrusion and backward cup extrusion was conducted with magnesium alloy, AZ31B. Process parameters such as forward extrusion ratio, backward extrusion ratio, and working temperature were controlled in a specific region and the effects of the parameter change were examined. Surface crack was developed in a certain state of the process parameters combination. The crack-free forming limit of the alloy in the combined process was disclosed by the parameter study. The microstructures of the initial and extruded workpieces were observed.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.5
• /
• pp.66-72
• /
• 2003

In case of hollow cylinder extrusion using porthole die, the effects of extrusion parameters-temperature, the speed of extrusion, the shape of the die and mandrel-on metal flow in porthole die extrusion of aluminum have been investigated. However, there have been few studies about condenser tube extruded by porthole die. Original metal flow of condenser tube by porthole die extrusion is similar to hollow cylinder extrusion but the estimation of metal flow for extrusion parameters is different. For example, variation of chamber length in hollow extrusion only affects the welding pressure, however, the welding chamber length in condenser tube extrusion influences to the welding pressure as well as the deflection of mandrel. This study was designed to evaluate metal flow, welding pressure, extrusion load, tendency of mandrel deflection according to angular variation in the bottom of chamber in porthole die. Estimation was carried out using finite element method in as non-steady state. Analytical results can provide useful information the optimal design of porthole die.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.10
• /
• pp.1541-1550
• /
• 2001

This paper describes experimental investigations in the direct extrusion of copper clad aluminum rods through conical dies. Composite materials consist of two or more different material layers. Copper clad aluminum composite materials are being used fur economic and structural purposes and the development of an efficient production method of copper clad aluminum composite material rods by extrusion is very important, It is necessary to know the conditions in which successful uniform extrusion ,and sound cladding may be carried out without any defects in the direct extrusion. There are several variables that have an influence on determining a sound clad extrusion. In order to investigate the influence of these parameters on the hot direct extrudability of the copper clad aluminum composite material rods, the experimental study have been performed with various extrusion temperatures, extrusion ratios and semi-cone angles of die. Subsequently, the microscopic inspection of interface bonding is carried out for extruded products. By measuring hardness, along extrusion way of products, a variation of hardness has been discussed. Proportional flow state has been considered by measuring radius ratio of Cu sleeve and Al core before and after extrusion.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.2
• /
• pp.660-665
• /
• 2014

Optimization of process parameters in polymer extrusion is an important task to reduce manufacturing cost. To determine the optimum values of the process parameters, it is essential to find their influence on the elongation of polymer breathable thin film. The significance of six important process parameters namely, extruder cylinder temperature, extruder speed, extruder dies temperature, cooling roll temperature, stretching ratio, stretching roll temperature on breathable film elongation of polymer extrusion was determined. Moreover, this paper presents the application of Taguchi method and analysis of variance(ANOVA) for maximization of the breathable film elongation influenced by extrusion parameters. The optimum parameter combination of extrusion process was obtained by using the analysis of signal-to-noise ratio. The conclusion revealed that stretching ratio were the most influential factor on the film elongation. The best results of film elongation were obtained at lower stretching ratio.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.3
• /
• pp.571-582
• /
• 1992

Soybeans were dry extruded at three different temperatures (125, 135 and $145^{\circ}C$) for 30 s. Four lambs fitted with cannulae in the rumen and abomasums were used in a balanced $4{\times}4$ Latin square design. Lambs were fed at 2 h intervals for 12 times a day with automatic feeder to maintain steady state conditions in digestive tract. A dual-phase marker system was used to estivate ruminal flow rate of both liquid and solid digesta. Objectives of this study were to determine the effect of extrusion temperature of raw soybean on the ruminal liquid and solid dilution rate, nitrogen digestion and flow at the abomasum and availability of amino acid in lambs. There were no significant effects of extrusion on liquid and solid dilution rate, and liquid volume. Ruminal liquid flow rate was not influenced by extrusion and ranged from 389 to 435 ml/hr. Extrusion had no influence on ruminal OM digestion and flow rate to the abomasums. Dietary N flow to the abomasums increased (p < 0.05) as extruding temperature increased. Extruding temperature had a significant effect (p < 0.05) on flow of N escaping ruminal degradation and ranged from 34.91 to 57.38%. Microbial N synthesized/kg OMTDR ranged from 27 to 37 g and highest with $145^{\circ}C$ ESB diet. Extrusion decreased the amount of degradable amino acid in the rumen and increased the supply of amino acid to the lower gut, especially with 135 and $145^{\circ}C$ ESB diets.