• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.245-250
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• 2003

This research conducted milling tests to study effects of cutting environment conditions of ball end mills on the characteristics of hard milling process. KP4 steels and STD11 heat treated steels were used as the workpiece and WC-Co ball end mill tools with TiAIN coated were utilized in the cutting tests. Dry cutting without coolant and semi-dry cutting using botanical oil coolant were conducted and MQL (Minimum Quantity Lubricant) device was used to spray coolant. Cutting forces, tool wear and surface roughness were measured in the cutting tests. Results showed that dry cutting of KP4 and hardened STD11 specimens produced better surface quality and wear performance than MQL spray cutting did.

• 소성∙가공
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• 제13권1호
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• pp.45-52
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• 2004

This research conducted milling tests to study effects of cutting environment conditions of ball end mills on the characteristics of hard milling process. KP4 steels and STD11 heat treated steels were used as the workpiece and WC-Co ball end mill tools with TiAlN coated were utilized in the cutting tests. Dry cutting without coolant and semi-dry cutting using botanical oil coolant were conducted and MQL(Minimum Quantity Lubricant) device was used to spray coolant. Cutting forces, tool wear and surface roughness were measured in the cutting tests. Results showed that dry cutting of KP4 and hardened STD11 specimens produced better surface quality and wear performance than MQL spray cutting did.

• 한국식품조리과학회지
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• 제11권3호
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• pp.213-219
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• 1995

습식 및 건식으로 제분방법을 달리하여 제조한 4종류의 쌀가루로 증편을 제조하여 품질특성을 살펴본 결과는 다음과 같다. 1. 증편의 수분함량은 쌀가루 자체의 수분함량과 비슷한 경향으로 습식제품이 건식제품보다 높았고 가수량 100％인 경우가 80％인 경우보다 높았다. 2. 증편의 색도는 제품의 수분함량이 높을수록 L값은 증가하고 a값과 b값은 감소하는 경향이었다. 저장기간이 경과함에 따라서는 L값은 다소 감소하고 b값은 다소 증가하는 경향이었다. 3. 증편의 기계적 texture측정결과 hardness는 대체로 건식제품이 습식제품보다 높게 나타났고 springiness는 습식제품의 경우는 가수량 80％에서, 건식제품의 경우는 가수량 100％조건에서 더 높았으며 전반적으로는 습식제품이 건식제품보다 높게 나타났다. cohesiveness는 습식제품이 건식제품보다 높았고 chewiness도 습식제품이 건식제품보다 높았다. 4. 증편의 관능검사 결과 whiteness는 습식제품이 건식제품보다 높았고 가수량이 100％인 경우가 80％인 경우보다 높았으며 moistness는 습식제품이 건식제품보다 촉촉하게 평가되었고 가수량이 100％인 경우에 80％인 경우보다 촉촉한 정도가 좋았다. softness는 건식제품이나 습식제품 중 입자가 작은 D-J와 W-P제품이 더 부드러웠고 springiness는 기계측정의 springiness와 비슷한 경향으로 습식제품이 건식제품보다 탄력성이 좋게 평가되었다. chewiness도 습식제품이 건식제품보다 높게 나타났고 기계측정의 chewiness와 같은 경향이었다. 그리고 overallquality는 습식제품이 건식제품보다 더 바람직한 것으로 평가되었다.

• 펄프종이기술
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• 제47권5호
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• pp.23-32
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• 2015

In this study, chemical and physical changes of dissolving pulps which have similar viscosity by dry milling and fractionation were investigated. We used two types of dissolving pulp made from wood and cotton linter fiber, respectively. Dry milling was executed by knife cutter and pulp powders were fractionated by sieve shaker into 4 grades. We analyzed fiber properties, crystallinity index, viscosity, molecular weight of pulp sheet and powders. It was found that poly-dispersity index of cotton linter pulp was smaller than that of wood pulp, meaning that cotton pulp has more narrow molecular weight distribution. It was assumed that these were related to exposure times to chemical treatment which cut cellulose chains not evenly. At least 4 times of chemical treatments for wood pulp were executed and only two times of chemical treatments for cotton linter pulp were done. After dry milling average molecular weight and crystallinity index of cotton linter pulp powders were reduced and these were related to fines content and shape of pulp powders.

• 한국분말재료학회지
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• 제28권6호
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• pp.462-469
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• 2021

Tin/graphite composites are prepared as anode materials for Li-ion batteries using a dry ball-milling process. The main experimental variables in this work are the ball milling time (0-8 h) and composition ratio (tin:graphite=5:95, 15:85, and 30:70 w/w) of graphite and tin powder. For comparison, a tin/graphite composite is prepared using wet ball milling. The morphology and structure of the different tin/graphite composites are investigated using X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and scanning and transmission electron microscopy. The electrochemical properties of the samples are also examined. The optimal dry ball milling time for the uniform mixing of graphite and tin is 6 h in a graphite-30wt.%Sn sample. The electrode prepared from the composite that is dry-ball-milled for 6 h exhibits the best cycle performance (discharge capacity after 50^th cycle: 308 mAh/g and capacity retention: 46%). The discharge capacity after the 50^th cycle is approximately 112 mAh/g, higher than that when the electrode is composed of only graphite (196 mAh/g after 50^th cycle). This result indicates that it is possible to manufacture a tin/graphite composite anode material that can effectively buffer the volume change that occurs during cycling, even using a simple dry ball-milling process.

• 한국세라믹학회지
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• 제34권11호
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• pp.1187-1197
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• 1997

Dry gel composed of primary particles more homogeneous than starting boehmite powder was prepared by dispersing and gelling the boehmite powder. The transformation temperatures of boehmite powder, dry gel seeded with 0, 1, 3, 5 wt% $\alpha$-Al2O3, and ball milled gel were 1192$^{\circ}C$, 1184$^{\circ}C$, 1141$^{\circ}C$, 1119$^{\circ}C$, 1117$^{\circ}C$, and 1106$^{\circ}C$, respectively. Sintering behavior of dry gel without seed was similar to that of boehmite powder, but the sintered density of dry gel was improved as much as 10%~15% than boehmite powder. In the case of dry gel seeded with 5 wt% $\alpha$-Al2O3, sintering behavior was much improved. The relative density of the gel seeded with 5 wt% $\alpha$-Al2O3 was 96% when sintered at 140$0^{\circ}C$ for 1h. On the other hand, ball milling of the non-seeded sol for 48h resulted in the relative density of 97% when sintered at 130$0^{\circ}C$ for 1h. The size and amount of $\alpha$-Al2O3 particles added by ball milling were 0.107 ${\mu}{\textrm}{m}$ and 0.5 wt%.

• 한국식품영양과학회지
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• 제37권7호
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• pp.900-907
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• 2008

중간소재용 흑미 쌀가루 제조를 위한 조건을 검토하기 위하여 제분조건별 쌀가루의 이화학적 특성을 비교분석하였다. 흑미의 수분흡수속도상수($k_o$)는 $25^{\circ}C$에서 $0.013\;min^{-1/2}$, $35^{\circ}C$에서 $0.016\;min^{-1/2}$, $45^{\circ}C$에서 $0.018\;min^{-1/2}$로 수침온도가 높아짐에 따라 값이 증가하였고, anthocyanin 용출정도도 수침온도 상승과 수침시간 증가에 따라 크게 영향을 받았다. 일반성분과 anthocyanin의 함량은 건식쌀가루에 비해 습식쌀가루가 낮게 나타났으며 제분횟수의 증가에는 영향을 받지 않았다. 건식쌀가루의 평균 입도는 $379{\sim}288\;{\mu}m$로 습식쌀가루의 $336{\sim}253\;{\mu}m$보다 컸으며 제분횟수가 증가함에 따라 60 mesh 이상의 쌀가루 분포비율이 증가하고 쌀가루의 입도가 고르게 분포되는 경향을 보였다. 쌀가루 요오드 반응의 ${\lambda}max$는 $521{\sim}522\;nm$으로 제분조건에 큰 영향을 받지 않았으나, 아밀로스 함량을 제외한 전분손상도, 수분분용 해지수(WSI) 및 수분흡수지수(WAI)는 건식쌀가루보다 습식쌀가루에서 높았다. RVA 호화양상에서 습식쌀가루의 호화온도가 $46.1{\sim}46.4^{\circ}C$에 비하여 건식쌀가루는 $62.5{\sim}69.4^{\circ}C$로 훨씬 높았으며, 습식제분의 경우 제분횟수에 따른 차이가 뚜렷하게 나타나지 않았으나 건식제분에서는 5회 처리까지 호화 온도 감소 현상이 나타났다. 또한 건식 및 습식 쌀가루 모두 제분횟수가 증가하면서 trough, 최종점도 및 consistency는 감소하였고, setback과 breakdown은 건식쌀가루에서는 증가한 반면 습식쌀가루에서는 감소되는 상반된 양상을 보였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.66-70
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• 2003

Recently, environmental conscious machining becomes one of the most important technology in modern manufacturing industry. Especially in metal cutting, cutting fluid often results in many environmental problems. Many technologies have been developed to reduce the problems of the cutting fluid. But most of the technologies need another devices which sometimes require large space and also are very expensive, such as cooling system. In this paper, air compressor is only used to replace the functions of cutting fluid as semi-dry cutting. Cutting forces, cutting moments, and tool wear were measured to obtain cutting characteristics, and were compared with those of dry cutting and non-dry cutting. In the results of the experiments, semi-dry cutting was found to show better cutting performances than dry cutting and non-dry cutting.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.238-244
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• 2004

This research conducted milling tests to study effects of cutting environment conditions of ball end milts on the characteristics of high speed milling cutting process. KP4 steels and STD11 heat treated steels were used as the workpiece and WC-Co ball end mill tools with TiAIN coated were utilized in the cutting tests. Dry cutting without coolant and semidry cutting using botanical oil coolant by the MQL(Minimum Quantity Lubricant) device were conducted. Cutting forces, tool wear and surface roughness were measured in the cutting tests. Results showed that MQL spray cutting of KP4 and hardened STD11 specimens produced better surface quality and wear performance than dry cutting did.

• 한국식품영양학회지
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• 제28권6호
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• pp.1065-1070
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• 2015

초다수성 가공용 품종인 보람찬 및 한마음 품종의 수분 함량, 수분결합도, 아밀로오즈 함량, 손상전분, 입도 분포 및 호화특성을 분석하였다. 국내 초다수성 품종의 습식 및 건식분쇄에 의한 쌀가루의 수분 함량은 보람찬 및 한마음의 경우, 각각 14.79, 13.56 및 7.98, 7.14%를 나타냈다. 수분결합도의 경우, 보람찬 및 한마음 시료는 습식과 건식분쇄에 의해서 각각 236.67, 231.35% 및 275.83, 279.73%를 나타내어 건식분쇄에 의해 수분결합도가 증가하는 것으로 확인되었다. 습식분쇄된 초다수성 쌀가루의 수분결합력은 대조구로 사용된 일반미의 수분결합력과 비교 시 낮게 나타나는 것으로 확인되었다. 건식분쇄에 의한 호품, 보람찬 및 한마음 품종의 아밀로오즈 함량은 각각 19.12, 19.55 및 19.59%를 나타내었다. 손상전분의 경우, 보람찬 및 한마음 시료의 경우 습식과 건식분쇄에 의해 12.51, 10.69 및 14.98, 15.22%를 나타내어 습식분쇄에 비해 건식분쇄했을 경우 전분손상도가 증가하는 것으로 확인되었다. 또한 습식분쇄된 초다수성 쌀가루의 손상전분은 대조구에 비해 낮게 나타났으나, 건식분쇄 시에는 손상전분 함량이 대조구에 비해 증가하는 것으로 확인되었다. 국내 초다수성 품종의 분쇄방법에 따른 입도 분포의 경우, 최빈값은 습식에 비해 건식으로 분쇄할 경우 입도가 높은 것으로 나타났다. 초다수성 품종인 보람찬, 한마음을 습식 및 건식분쇄한 쌀가루의 최고 점도는 각각 2,300, 2,319 및 3,352, 3,022 cP를 나타내었다. 최고점도 및 최종점도의 경우 습식분쇄한 초다수성 쌀가루 시료는 대조구에 비해 높은 값을 나타내었다. Setback의 경우, 초다수성 품종 중 건식분쇄한 보람찬 쌀가루의 경우 가장 낮은 값을 나타내었으나, 대조구와 비교했을 경우 초다수성 쌀가루의 setback 값은 대조구에 비해 높은 값을 나타내었다.