• The Korean Journal of Rheology
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• v.9 no.3
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• pp.111-117
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• 1997

대표적인 신장유동의 하나인 방사공정을 통해 액정고분자를 포함한 블렌드 섬유의 신장유동의 특성과 형구학적 성질간의 관계를 고찰하였다. 신장유동에 의해 분산상인 액정 고분자는 미세섬유구조를 바뀌었고 압출온도가 높을수록 더욱 발달된 미세섬유구조를 가졌 다. 이러한 분산상의 미세구조 변화에 대한 설명은 블렌드의 신장유동특성을 나타내는 신장 점도비로서 가능하였다. 즉, 압출온도가 높을수록 방사사선에서 신장변형률속도가 z지고 신 장점도비가 작아지므로 분산상의 신장변형이 더 많이 되었다고 판단된다. 방사이전의블렌드 내의 분산상은 압출온도를달리하여도 모두 구형으로 존재함을 발견하였고 이사실로부터 분 산상의 미세섬유구조는 방사사선에서의 신장변형에 의해 주로 이루어졌음을 확인하였다.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.411-416
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• 2012

This study was carried out to investigate the effects of the extrusion process on the change of components in ginseng. The extraction yields from ginseng by distilled water extraction were highest in the extruded ginsengs, whereas it was lowest in the white ginseng. The contents of crude saponin were highest in the extruded ginseng, and they increased as the extrusion temperature was raised. The total contents of 11 kinds of ginsenosides increased in the order of red, white and extruded ginsengs. In particular, red ginseng showed higher contents of Rg1, Rg3 and Rb2, whereas Re was highest in white ginseng. In addition, the contents of Rg2, Rh1, Rh2 and Rg3 in the extruded white ginseng became higher. Free sugar contents were greatest in red ginseng. However, they were lowest in the extruded ginseng. White ginseng had a greater L value, whereas extruded ginseng demonstrated higher a and b values. In conclusion, the extraction yields, the contents of saponin, and ginsenoside-Rg2, Rh1, Rh2 and Rg3 were increased through the extrusion process.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.349-356
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• 1995

플라스틱 압출제품의 품질특성은 제품의 강도인데 제품의 강도는 일반중소기업체에서 별도의 측정기구를 갖추고 관리하기가 어려우므로 대용특성으로 제품이 중량을 사용하고 있다. 제품의 중량은 실린더의 온도와 금형의 온도 및 압출속도에 영향을 받는데 일반적으로 현장작업자의 경험과 감에 의존하여 상황에 따라 작업조건을 변화시켜 관리하고 있다. 그런데 작업조건을 관리하는 곳이 실린더에 5군데, 금형에 3군데 및 압출속도 등 아홉가지로 어느 인자가 전체 작업에 영향을 미치는 지 알수 없다. 이때 중회귀(Multiple Linear Regression)모델을 이용하여 실린더와 금형의 온도를 독립변수(Independent Variable)라 두고 제품의 중량을 종속변수(Dependent Variable)로 하여 최근 3개월간의 작업데이타를 수집하여 품질관리 전용 프로그램인 JUSE-QCAS를 사용하면 회귀선의 모수를 쉽게 추정할 수 있으며 제품의 중량에 영향을 미치는 실린더 및 금형의 온도를 관리 할 수 있어 품질을 안정적을 유지.관리할 수 있다.

• Journal of Ocean Engineering and Technology
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• v.11 no.2
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• pp.18-27
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• 1997

Al 6061 alloy reinforced with 10 vol.% ${\delta}-Al_2O_3$ short fiber was fabricated by Rheo-compocasting and squwwze cating. Extrusion processings were performed at temperatures from 40$0^{\circ}C$ to 55$0^{\circ}C$ with various extrusion ratio for curved shape dies. In proportion to the increase of extrusion ratios and temperatures, ultimate tensile strength for extruded materials improved. SEM observation of fractured surfsce was capcble oof accounting for fracture mechanism and bounding state of fiber and matrix.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.261-265
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• 2014

As the need for miniaturization in water purification filter increases, the development of filter media for single filtration with multiple function was strongly required. In this study, the molded activated carbon composed of single unit was manufactured by extrusion-sintering process, and then the flow rate, density and porosity were investigated using the molded activated carbon manufactured at various extrusion temperature. We confirmed that it was possible to manufacture the single unit-molded activated carbon when the extrusion temperature was $140{\sim}230^{\circ}C$ more than $133^{\circ}C$ being of polymer binder melting point, and the optimal extrusion temperature for the molded activated carbon with maximum flow rate was $170^{\circ}C$ since the molded activated carbon had low density and high through porosity. Also we confirmed that the flow rate through the molded activated carbon was strongly dependent upon through pore porosity compared to total porosity for the molded activated carbon.

• Food Engineering Progress
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• v.14 no.2
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• pp.127-134
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• 2010

This study was to develop high-nutritious energy bar from extruded hemp obtained by extrusion process. Mixture of rice flour and defatted hemp was extruded at a barrel temperature of 110 and 130$^{\circ}C$, and moisture content of 20 and 25%. Properties of extrudates such as bulk density, expansion index, breaking strength, apparent elastic modulus, water absorption index (WAI), water solubility index (WSI) have been analyzed. The antioxidant potential was determined by the DPPH-radical scavenging assay. The expansion index was the highest in rice-hemp extrudate at 130$^{\circ}C$ barrel temperature and 20% moisture content among the other hemp-added extrudates. The WAI was increased with increase in moisture content, while the WSI was increased with increase in barrel temperature. The peak viscosity of rice extrudate had higher valule than those of extrudate added with hemp. DPPH scavenging activity of rice-hemp extrudate at 130$^{\circ}C$ barrel temperature and 20% moisture content showed the highest value. Sensory properties, moisture content and color were assessed for quality of energy bar. The color values of the energy bar indicated decreasing L (lightness) and b (yellowness), and increasing a (redness) after 30 days storage at ambient condition. The highest overall acceptable was the energy bar added with rice-hemp extrudate at 130$^{\circ}C$ barrel temperature and 20% moisture content.

• Journal of the Korean Magnetics Society
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• v.6 no.5
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• pp.310-316
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• 1996

In this study magnetic properties of anisotropic ferrite bonded magnets produced by extrusion molding with a variety of magnetic field, extrusion mold temperature and extrusion rate were investigated. X-ray diffraction study showed the alignment of magnetic powder was decreased by molten flow in extrusion mold. When the temperature of extrusion mold was $20^{\circ}C$, the degree of alignment as much as 82% could be achieved under the applied magnetic field of 4 kOe. The bonded magnets having the remanence of 2.2 kG was able to fabricated by extrusion molding when the packing density of Sr-ferrite powder was 50 vol%.

• Food Science and Preservation
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• v.14 no.5
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• pp.451-456
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• 2007

The vitamin C content in extruded comstarch matrix was shown to depend on extrusion process variables (barrel temperature and water content), the packaging method, and the storage period. In addition, loss rates of vitamin C under different processing conditions were calculated. Extrusion process variable were barrel temperature ($80^{\circ}C,\;90^{\circ}C,\;100^{\circ}C$ and $110^{\circ}C$), and water content (25% 30% both w/w). The vitamin C content decreased as barrel temperature increased from $80^{\circ}C$ to $110^{\circ}C$ and water content increased from 25% to 30% when either LDPE plastic film packaging or ON film vacuum packaging were employed. As barrel temperature and water content increased, vitamin C decreased in comstarch packed in either LDPE film or ON film. As temperature increased, vitamin C loss rate increased under both packaging conditions, but the loss tate was only 50% of the LDPE film packaging rate when ON film vacuum packaging was used. In conclusion, the higher the temperature, and the greater the water content, the less vitamin C was inactivated during extrusion cooking, although the loss rah of vitamin C became faster as temperature and water content rose. In conclusion, extrusion process could be applied for making vitamin C matrix to extend vitamin C preservation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.1018-1024
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• 2008

The objective of this study is to compare the physicochemical properties and release characteristics of red ginseng (A) and tissue cultured mountain ginseng (B) extruded tissue cultured mountain ginsengs at barrel temperatures 110 (C) and $120^{\circ}C$ (D) to produce tissue cultured mountain ginseng-like comercial red ginseng by extrusion process. Extrusion process variables, water content and screw speed were fixed at 25% and 200 rpm, respectively. In the results, reducing and total sugar content were found to be relatively higher in A. The acidic polysaccharides content of B was the lowest among the ginseng samples. Acidic polysaccharide was increased 3 times by extrusion process. A and B were three times higher at maximum than C and D in polyphenolic compound. Polyphenolic compound content was relatively low by extrusion of ginsengs. Amino acid contents of B, C and D were $35{\sim}42\;{\mu}g/mL$; in contrast, A contained $25\;{\mu}g/mL$. The crude saponin content of C and D were higher than A and B.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.361-368
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• 2006

Extruded ginseng was manufactured using twin-screw extruder under 300 rpm screw speed, 21 kg/hr feed rate, $80-150^{\circ}C$ extrusion temperature, and by addition of water (12.1-30.6%). Extraction yield and contents of total carbohydrate and uronic acid in extruded ginseng at room temperature extraction (RT) increased with increasing extrusion temperature, whereas those of boiling temperature extracts (BT) were not affected by increasing extrusion temperature. Contents of nonstarch polysaccharide (NSP) in RT and BT extracts increased 340 and 142%, respectively, compared to that of raw ginseng. Main sugar compositions of NSP in RT and BT extracts were arabinose, galactose, and glucose. Extraction yields of total and crude saponins in extruded ginseng at optimize extrusion condition were higher than that of raw ginseng. In RT extracts, molecular weights of polysaccharides from raw were higher than that of extruded ginseng polymer, whereas in BT extracts molecular weights of polysaccharides from extruded ginseng were higher than those of raw ginseng polysaccharides.