• 펄프종이기술
• /
• 제41권1호
• /
• pp.52-60
• /
• 2009

A printing defect known as fluting (or waviness) of the web printed by heatset web offset printing process is one of the chronically serious problems deteriorating print quality. In this paper, fluting occurrence on uncoated papers was explored in terms of many printing conditions including drying temperature, fountain solution amount, ink supply, and press configurations. For this purpose, fluting on prints from real press runs was appraised in a quantitative manner. As results, ink supply was a distinctive factor for fluting such that the lower ink amount, the milder fluting. However increase in fountain solution seemed to make fluting severer while the effect of drying temperature was inconsistent for each paper. This result might indicate variable drying requirements for each paper. Thereby it was suggested that the optimum drying conditions related to the printabilities of each paper need to be established to minimize fluting potential. A press with short dryer and drastic cooling unit produced higher fluting. Suggestions for future work were given along with interpretation for the results.

• 소성∙가공
• /
• 제16권4호
• /
• pp.317-322
• /
• 2007

In order to investigate the cause and condition of fluting in tangential bending of low carbon steel sheet, an analytic analysis, an experiment and a series of finite element analysis for bending process were done. The fluting in bended sheet was related with the yield point elongation of material. Due to the yield point elongation, unstable plastic hinge was occurred in course of bending of elastic perfectly plastic sheet. According to the analysis and computational results, lower yield point elongation than 5% was required to prevent fluting in 0.5-0.6t sheet in $15{\sim}25mm$ radius bending. The tendency of fluting occurrence was reduced as decreasing the radius of bending, increasing thickness of bended sheet, and removing irregularity in sheet and bending processes.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2007년도 춘계학술대회 논문집
• /
• pp.336-339
• /
• 2007

In order to investigate the cause of fluting in tangential bending of low carbon steel sheet, an analytic analysis, an experiment and a series of finite element analysis for bending process were done. The fluting in bended sheet was due to the yield point elongation of material. Due to the yield point elongation, unstable plastic hinge was occurred in course of bending of elastic perfectly plastic sheet. According to the analysis and computational results, lower yield point elongation than 5% was required to prevent fluting in $0.5{\sim}0.6t$ sheet in $15{\sim}20mm$ radius bending.

• 소성∙가공
• /
• 제24권4호
• /
• pp.241-247
• /
• 2015

In order to prevent shape defects such as fluting and stretcher strains during press forming of aged low carbon steel sheets, roller leveling conditions for reducing yield point elongation were studied. Yield point elongations of leveled sheets were determined as a function of leveling, which is defined as the plastic fraction or the ratio of plastically deformed part in sheet thickness section to the whole thickness of the sheet. By adjusting this plastic fraction during leveling to more than 78%, yield point elongation in the leveled sheets was reduced so no fluting occurred during subsequent tangential bending. Stretcher strains can be avoided by leveling the sheet to an 84% plastic fraction condition.

• 산업식품공학
• /
• 제14권2호
• /
• pp.106-111
• /
• 2010

본 연구는 일정한 실험조건 하에서 골심지 시료에 따른 골 성형 실험을 행하여 골심지에 의한 하이로골의 발생과 골판지상자의 압축강도의 관계에 대하여 조사하였다. 골판지의 골 높이가 낮은 골(low corrugation)의 비율이 많은 골심지 그레이드는 장력 변동의 저항에도 약하며 골심지의 이탈력에 의한 강탈(stealing)이 일어나기 쉽고, 결과적으로 낮은 골 비율이 높아졌으며, 골심지 두께 편차가 큰 골심지는 골 성형 시에 슬립현상을 발생하기 쉽기 때문에 불규칙한 골을 연속 형성하는 경향이 있었다. 또한 골심지의 그레이드에 따른 하이로골 분포비율의 실험결과 일반적 경향으로는 그레이드가 높은 골심지 일수록 낮은 골비율이 적었다. 골 성형된 골판지 시트의 두께의 경우는 원지 평량과의 상관성은 적고 골심지 두께와 상관하며 y=3.9732x+4.2712, $R^{2}=0.8142$), 골심지의 밀도에 역상관한다((y=-3.1213x+6.8736, $R^{2}=0.9919$). 하이로골 중에서 낮은 골 분포를 크게 나타낸 골심지 재료의 골판지로 만든 골판지상자의 압축강도가 현저히 낮고 골심지 시료의 그레이드에 따라 13%의 차이가 있었으며 압축강도의 편차도 골심지의 시료에 따라 21%로 크며, 골심지 골은 원지의 두께 및 밀도 등 물리적 특성치의 변동과 관계한다.

• 펄프종이기술
• /
• 제40권2호
• /
• pp.37-42
• /
• 2008

Defects of corrugated board were limiting factors to the corrugated industry's growth. On-line detecting systems of defects are beneficial to increase profits of the corrugated board companies by reducing base paper consumption, increasing process reliability, and increasing productivity. By replacing naked eye inspection of defects to a defects detecting system, continuous inspection without fatigue may guarantee final products quality. The system was developed, which was consisted of line scan CCD camera, lens, illuminating parts, high speed image processor, software, various input parts, and output parts. First installation location of the system was at before fluting process after base paper unwinding, and surface of liner board was inspected by the system. Second installation location was after fluting process and combining process for liner board. Production loss includes ragged appearance of edge, irregular flute shape, wrong combination of flute, score cracking, defects in base paper, and flute cracking. The production loss was analyzed before and after the system installation at a commercial domestic mill. The production loss ratio was defined as a production loss weight per total production weight. The production loss ratio before the installation was decreased a lot from 1.28%(during 3 months before installation) to 0.76%(during 12 months after the first installation) and to 0.25%(during 6 months after the second installation).

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
• /
• pp.552-554
• /
• 1999

In this paper, a robust control system with the disturbance observer is proposed for BLDC servo system. The overall control system consists of the speed controller which is implemented with PI controller and the disturbance observer with free parameters. The proposed control system is designed the command input response and the closed loop characteristics independently by using two-degrees-of-freedom concept, so it can improve the closed loop characteristics with no influence on the command input response. The effective suppression of disturbance with the observer improves the characteristics of the closed loop of the system. And also, by fluting the bandwidth of free parameters, measurement noise is considered. To verify the better performance of the proposed control system than that of the conventional PI controllers, the performance of the controller is analyzed theoretically and some simulation results are presented.

• 한국반도체및디스플레이장비학회:학술대회논문집
• /
• 한국반도체및디스플레이장비학회 2006년도 추계학술대회 발표 논문집
• /
• pp.184-189
• /
• 2006

In the process of accurate manufacture and measurement, it is necessarily required to isolate external or internal vibration due to external disturbance and internal actuators. The higher vibration isolation system gets damping around resonance, the better it is generally. This paper analyzes the performance of an existing passive air-spring for vibration isolation table by rising experiment and simulation. Optimal design for a passive air spring can be obtained by fluting the size of the orifice. Also design for an active isolation system is carried out by applying PID controller and considering non-linearity of pneumatic characteristics with help of look-up table. We have developed the act ive vibration isolation table wi th the bet ter isolation performance.

• 한국실내디자인학회:학술대회논문집
• /
• 한국실내디자인학회 2005년도 춘계학술발표대회 논문집
• /
• pp.273-274
• /
• 2005

The purpose of this design is to find out the design for an ophthalmic hospital focusing on the patient needs and changed healthcare environment. A cellularized hospital system appears variety design. This space needs well-balanced and ease of mind, because of ophthalmic needs a clear description attention. The concept of this design is to give human colour intellect and rich colour-sense. The waiting area wall is finished the graphic design sheet of leaves, which is covered with the fluting glass and indirect lighting. The colour is extracted in nature. The colour techniques of graphic design is gradation, the colour plan select from Y to G-GB. The material is selected within natural colour. The treatment area is functional space and the waiting area is sensitivity space. The hospital design must change with user as a leader.

• 암석학회지
• /
• 제18권3호
• /
• pp.211-221
• /
• 2009

울산시 이진리 지역에 분포하는 미문상 화강암에 대한 암석학적 특징이 지형형성에 미치는 영향을 분석하였다. 연구지역의 화강암은 대부분 담갈색 내지 회백색을 띠며, 1~2 mm 내외의 중립 내지 세립의 석영 및 정장석으로 구성되어있다. 대부분 석영과 정장석이 연정을 형성하여 미문상 조직을 보인다. 미문상화강암이 분포한 연구지역에는 인셀베르그, 토르, 타포니, 나마와 같은 미지형이 관찰된다. 연구지역의 북측에는 타포니가, 남측에는 나마가 주로 발달해 있으며, 연구지역 전역에 걸쳐 플루팅 코어와 래이즈드 림이 나타난다. 미문상 화강암의 조직적 특징을 분류기준으로 하여 외대(A) 내대(B)로 구분하였으며, 미문상 조직이 내대에서 외대로 갈수록 뚜렷해지는 경향을 보였다. 지형학적 특징이 이에 부합하여 나타난다. 즉, 외대의 지형학적 특징은 범바위 같은 타포니로 이루어진 미지형이 주로 나타나며, 내대는 차일암과 같은 대(platform)로 대표되는데 이는 암석학적 특성이 관련된 것으로 판단된다. 연구지역 전역에 걸쳐 나타나는 플루팅 코어, 래이즈드 림 등의 특이지형은 미문상 화강암의 성인과 관련된 정동의 발달과 연관되어 있으며, 타포니, 나마 등의 미지형 형성에도 기원적인 요소로 작용했던 것으로 해석된다. 암석의 입도와 정동의 분포 상태 등의 조직적 차이가 미지형의 발달에 영향을 미치는 것으로 판단된다.