• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 춘계학술대회논문집
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• pp.54-61
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• 1995

Simultaneous forward-backward extrusion upsetting has been carried out by ratray forging. Two materials has been used commericaly 6.61 aluminium ally and 0.2% steel. The effects of working conditions ; spiral feed ; initial aspect ration of specimen and lubricating condition on the backward and forward extrusion were clarified. The extrusion length increases a sthe aspect rationof the specimen increases, the backward extrusion lengthbeing relatively larger than the forward one. The effects of the spiral feed and the material on the extrusion lengthis remarkably large for the large spiral feed.

• 축산식품과학과 산업
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• 제10권1호
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• pp.22-30
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• 2021

• 한국수산과학회지
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• 제52권3호
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• pp.247-255
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• 2019

This study was conducted to investigate the effects of extrusion pressure and particle size of feed ingredients on the growth performance and plasma hormone activity in juvenile olive flounder Paralichthys olivaceus. Experimental diets were prepared with extrusion pressure manipulated by screw speed [low pressure (LP), 885 rpm/min; high pressure (HP), 708 rpm/min] and different dietary particle sizes [specific surface area: small (SS), $169.9m^2/kg$; large (LS), $67.4m^2/kg$] in a two-level factorial design. Four experimental diets (LP+SS, LP+LS, HP+SS, and HP+LS) were randomly assigned to 12 tanks (3 replicates) stocked with 20 fish (initial weight, 57 g) per tank. After a 4-week feeding trial, the observable trends of the main effects of extrusion pressure and particle size on growth performance showed that LP and SS enhanced fish weight gain. The plasma insulin-like growth factor-I level was significantly higher in fish fed the LP+SS diet than in fish fed the HP+SS diet. These results indicate that manipulation of the physical qualities of feed through adjustment of extrusion pressure and feed ingredient particle size may influence the growth performance of juvenile olive flounder, which should be considered in feed manufacture.

• Preventive Nutrition and Food Science
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• 제17권3호
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• pp.203-209
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• 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.

• 한국식품과학회지
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• 제27권3호
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• pp.404-413
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• 1995

밀기울의 물리화학적 변형을 유도하기 위하여 3가지 형태의 스크류 조합을 달리한 이축 압출성형 가공시 수반되는 시스템 변수(압출온도, 압출압력, 기계적에너지 소모율, 평균 체류시간)의 변화를 분석하였다. 스크류는 reverse screw element(RSE)를 바렐의 중앙부에 3, 4 및 5개를 조합한 형태를 사용하여 스크류의 회전속도 $280{\sim}380\;rpm$, 원료의 공급속도 $22{\sim}38\;kg/hr$, 원료의 수분함량 $17{\sim}33%$ 범위에서 압출성형을 실시하였다. 압출온도는 RSE의 갯수가 증가할수록 상승하였고, 원료의 공급량과 수분함량이 증가할수록 감소하였다. 압출압력은 원료의 충진율이 감소하면 낮아졌으며, RSE가 많을수록 압출온도가 상승함으로서 용융물질의 점도가 떨어져 압력이 감소하였다. 또 원료의 공급량이 증가하고 원료의 수분함량이 낮을수록 압출압력이 감소하였다. 기계적에너지 소모율(specific mechanical energy; SME)은 원료의 공급량과 수분함량이 증가할수록 감소하였으며, RSE의 갯수를 3개에서 5개로 조합하여 사용함에 따라서 SME가 증가하였다. 평균체류시간(RT)은 RSE를 4개 조합한 경우가 가장 길었고, die hole의 크기가 작을수록 RT도 증가하였다. 원료의 공급량이 증가함에 따라서 RT는 감소하였으며, 원료의 수분함량이 증가될수록 RSE가 3개인 경우에는 RT가 증가하였고 4개 및 5개인 경우는 감소하였다.

• Preventive Nutrition and Food Science
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• 제19권2호
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• pp.124-127
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• 2014

The effect of feed moisture contents (30%, 40%, and 50%) and screw speed (200 rpm, 250 rpm, and 300 rpm) on the corn fiber gum (CFG) yield and soluble arabinoxylans (SAX) content of destarched corn fiber was investigated. The CFG yields and SAX contents of extruded, destarched corn fiber were higher than that of destarched corn fiber. In extruded, destarched corn fiber, increased screw speed and decreased feed moisture contents resulted in a higher SAX contents. The maximum yields of CFG obtained from extruded, destarched corn fiber were $79.1{\pm}19.0g/kg$ (30% feed moisture content) and $82.3{\pm}11.30g/kg$ (300 rpm screw speed). The highest SAX content was also observed at a screw speed of 300 rpm. The results of the present study show that water extraction and extrusion combined have the potential to increase CFG and SAX yields from corn fiber.

• Preventive Nutrition and Food Science
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• 제6권3호
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• pp.163-169
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• 2001

To produce expanded, minimally hard extrudates from blends of raw pork meat (20%), defatted soy flour (25%), and corn starch using a single-screw extruder, various combinations of feed moisture, process temperature, and screw speed were evaluated. First series of extrusion runs were conducted according to a central composite rotatable design/response surface methodology (RSM). Upon assessing the full model for each response, insignificant terms were eliminated to determine final response surface models. Screw speed within the range evaluated was found to have no significant effect on expansion ratio (ER) or shear force (SF) of extrudates. Since examinations of the response surfaces and their generated grids of predicted values indicated that maximum ER and minimum SF were likely to be attained with a moisture-temperature combination outside the RSM experimental range, the second series of extrusion runs were conducted with several selected combinations of moisture and temperature to determine a practical optimum extrusion condition. The combination of 22.78% feed moisture, 16$0^{\circ}C$ process temperature, and 170 rpm screw speed was chosen as such a condition, and used in the final extrusion. The final product required less force to break than did commercial pretzel sticks.

• Animal Bioscience
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• 제36권10호
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• pp.1546-1557
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• 2023

Objective: The present study aimed to evaluate the effects of extruded and unextruded feeding on the performance, milk composition, digestibility and ruminal fermentation of dairy cows through a meta-analysis. Methods: The database was compiled from 53 studies in Scopus and PubMed. The data were analyzed using a random effects model in OpenMEE software. Extruded feed was grouped as the experiment group while and the others as control group. The bias of publication in the main parameter of dairy performance was evaluated by a funnel plot. Results: The result showed that extruded feed enhanced the milk yield, dry matter and crude protein digestibility, butyrate and valerate acid production (p<0.05). Meanwhile, the extruded feed significantly decreased the milk fat and protein concentration (p<0.05). Also, the iso-butyrate and iso-valerate in unextruded feeding was significantly higher than the extruded feed (p<0.05). Conclusion: It was concluded from the meta-analysis that extruded feed effectively improved the milk production and milk lactose concentration, dry matter and protein digestibility, but not the milk fat and protein concentration.

• Journal of Biosystems Engineering
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• 제30권1호
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• pp.8-16
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• 2005

The extrusion-cooking condition on Cordyceps pruinosa was designed using twin-screw extruder. Response surface methodology (RSM) was used to investigate extrusion-cooking using a central composition design with varying die temperature $(114-146^{\circ}C)$, feed moisture $(22-38\%)$, feed rate (4-14 ka/h) and screw speed (120-280 rpm). System parameters (die pressure and specific mechanical energy (SME)) and extrudate parameters (density and water solubility index (WSI)) were statically analyzed using RSH. Die pressure was significantly affected by temperature, moisture contents and feed rate. SM was affected by screw speed and feed rate. When die temperature is $130^{\circ}C$ and moisture content $25\%$, the optimum pressure is shown. SME is about 20 Wh/kg, when feed rate is $10\~12kg/min$ and screw speed $200\~250rpm$. WSI was affected by temperature and moisture contents. Density was not affected by any factor. WSI increases by $7\%$ from about $23\%$ to about $30\%$, as temperature is raised from $120^{\circ}C\;to\;140^{\circ}C$. The WSI of Cordyceps pruinosa pulverized after extruding (PE) is about $26.97\%$ higher than that of raw material and $10\%$ higher than that of pulverized after drying (PD). The content of unsaturated fatty acid were not significantly different in PD and PE. Anti-oxidative activity of PE was 1.67-2.2 times higher than that of PD in Cordyceps pruinosa using 1- dipheny1-2-picrylhydrazyl method (DPPH).

• 한국가금학회지
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• 제17권4호
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• pp.284-295
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• 1990

Extrusion을 달리한 밀기울과 무기태린의 첨가수준의 주요 영양소의 소화율에 미치는 영향을 살펴보고자 증체양, 사료섭취량, 사료효율, 영양소별 소화율, 그리고 tibia의 성분량 변화에 대하여 조사하였다. 1) 증체양은 무기태린의 첨가수준이 0.225％, 0.45％일 경우 Extrusion처리구보다 Non－Extrusion처리구에서 높은 경향을 보였으나, 처리간에 유의성은 찾아 볼 수 없었다. 한편 Extrusion처리에 관계없이 무기태린의 첨가로 증체량이 개선되었으며 인을 첨가한 두처리구(0.225％와 0.45％) 사이에서는 유의성을 인정할 수 없었다. 2) 사요섭취양은 무기태린의 첨가구와 무기태린에서 Non－Extrusion처리구보다 Extrusion처리구에서 높은 경향을 찾아볼 수 있었다. 3) 사료효율은 무기태린을 첨가함으로써 개선되었으나, 인을 첨가한 두 처리구(0.225％와 0.45％) 사이에서는 유의성을 인정할 수 없었다. 4) 건물 소화율은 무기태린의 첨가수준이 높을수록 개선되었으나, Extrusion핵과는 인정할 수 없었다. 5) 인을 첨가한 두 처리구(0.225％와 0.45％) 사이에서 단백질 소화율은 Non－Extrusion 보다 Extrusion처리구가 높았으나, 증체에 직접적인 영향은 없었다. 6) Tibia의 Ca과 P의 함양은 무기태린의 첨가수준에 따라 증가하는 경향을 보였으나, 이러한 증가양상에서 P의 첨가수준과의 직접적인 관계는 찾아볼 수는 없었다.