• 한국정밀공학회지
• /
• 제20권7호
• /
• pp.217-226
• /
• 2003

Twin screw extruders are the heart of the polymer processing industry. They are used at some stage in nearly all polymer processing operations. This paper is concerned with the basic elements of the extruder design. The proper design of the geometry of the extruder screw is of crucial importance to the proper functioning of the extruder. If the material transport instabilities occur as a result of improper screw geometry, even the most sophisticated computerized control system cannot solve the problem. For this purpose, a characteristic design on the screw flights shape of the closely intermeshing co-rotating twin screw extruder. This paper presents design parameters of double flighted screw and triple flighted screw elements, and characteristics of various screw channel area versus screw diameter ratio, K value, in the barrel of screw extruder.

• 한국자동차공학회논문집
• /
• 제8권2호
• /
• pp.72-80
• /
• 2000

This study aims at the optimal design of the screw rotor, its performance analysis, and development of a small screw supercharger which has a low noise compared with the root type supercharger. The basic theoretical equations and the basic design of the screw supercharger have been established. The optical design of the screw rotor's shape has been also performed theoretically. Also, the performance analysis technique of the designed screw rotor has been developed.

• 한국정밀공학회지
• /
• 제20권8호
• /
• pp.185-193
• /
• 2003

The modular self-wiping co-rotating twin screw extruder (SWCOR) has become the most important of twin screw machines. Screw design is one of the most important factors in determining performance of screw extruder. The screw flight and screw channel geometry of SWCOR is determined by the screw diameter, centerline distance, helix angle, and flights number. The maximum allowable throughput rate on a twin screw extruder is determined by a combination of free volume and available specific torque. In this paper we designed geometrical parameters of extruder screw and presented optimal specific torque value in K=1.55, and then developed screw design program for the screw cutting by the use of JAVA API in the twin screw extruder.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
• /
• pp.292-297
• /
• 2001

Twin screw extruders are the heart of the polymer processing industry. They are used at some stage in nearly all polymer processing operations. This paper is concerned with the basic elements of the extruder design. The proper design of the geometry of the extruder screw is of crucial importance to the proper functioning of the extruder. If the material transport instabilities occur as a result of improper screw geometry, even the most sophisticated computerized control system cannot solve the problem. For this purpose, a characteristic design on flights shape of the extruder screw. This paper presents cross section designs of a closely intermeshing twin screw extruder with double-flighted screw elements, and channel depth characteristics for a double flighted corotating self-wiping twin screw extruder.

• 대한치과보철학회지
• /
• 제43권2호
• /
• pp.258-263
• /
• 2005

Statement of problem. Implant screw loosening has been remained a problem in implant prosthodontics. The time needed to insert screw driver into abutment screw head should be shortened for the purpose of decreasing the chair time. Purpose. The purpose of this study was to investigate the effects of the design of abutment screw driver on the amount of time for insertion of screw driver into abutment screw head. Material and methods. Hexagonal and rectangular types of abutment screw drivers were used. The original abutment screw drivers were modified by grinding acute angle of the screw driver tip (modified drivers). Group 1 : hexagonal type abutment screw and original driver Group 2 : hexagonal type abutment screw and modified driver Group 3 : rectangular type abutment screw and original driver Group 4 : rectangular type abutment screw and modified driver UCLA lab analogues were located in acrylic resin block. The angulations of them were 0 and 20 degrees. The times needed for insertion were measured. Group 1 and 3 were used as controls. Results. 1. Group 2 showed shorter insertion time than group 1, regardless of implant angulations (p<.05). 2. Group 4 showed shorter insertion time than group 3, regardless of implant angulations (p<.05). Conclusion. Modified abutment screw drivers required less amount of time to insert screw driver into abutment screw head. Modification of abutment screw driver was beneficial.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1996년도 추계학술대회 논문
• /
• pp.79-84
• /
• 1996

Recently a symmetric and non-symmetric profile of screw rotor has been designed in the interior. Howere the processing method of screw rotor and the cutter design for screw rotor were not studied. Therefor we could not make the shape of the screw rotor designed by profile function with computer. In this study we have made cutter profile design program and manufactured cutters for screw rotors using H.S.S We machined screw rotors of symmetric 4x6 profile non-sysmmetric 4x6 profile with almighty milling machine.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1994년도 추계학술대회 논문집
• /
• pp.907-912
• /
• 1994

Recently, a symmetric and non-symmetric profile of screw rotor has been designed in the interior. However the processing method of screw rotor and the cutter design for screw rotor were not studied. Therefore we could we could not make the shape of the screw rotor designed by profile function with computer. In this study, we have made cutter profile design program, and manufactured cutters for screw rotors using H.S.S. We have machined screw rotorts of symmetric 4*6 profile, non-symmetric 4*6 profile with almighty milling machine.

• 드라이브 ㆍ 컨트롤
• /
• 제11권4호
• /
• pp.46-52
• /
• 2014

This study suggests a small-sized screw decanter specialized for dredging sites. Generally, conventional screw decanters are composed of a cylinder and a cone. However, the suggested screw decanter simply has a cone based on a cone-type bowl structure. In this research, a commercial analysis tool is used to establish an optimal design for the bowl and the screw conveyor. Moreover, the base frame, where the main bearings that support the spindle of the bowl and the screw conveyor are installed, is optimally designed considering the weight of the rotating body and the deflection caused by the high centrifugal force. Furthermore, the natural frequency range of the spinning body, the bowl and the screw conveyor, is applied to this base frame; it is designed not to correspond to the resonance frequency range and achieves stability as a result. This study suggests an optimal design for the rotating body and the base frame of a screw decanter considering its vibration characteristics. Such a design will prevent overuse of materials and help to reduce the weight and volume-and the price-of a screw decanter.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.824-828
• /
• 2002

Twin screw extruders are the heart of the polymer processing industry. The single most important mechanical element of a screw extruder is the screw. The proper design of the geometry of the excluder screw is of crucial importance to the proper functioning of the extruder. If material transport instabilities occur as a result of improper screw geometry, even the most sophisticated computerized control system cannot solve the problem. For this purpose, Tool shape design for the screw flights cutting in twin screw extruder.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.706-709
• /
• 1997

Extruders are the heart of the polymer processing industry. The single most important mechanical element of a screw extruder is the screw. The proper design of the geometriy of the extruder screw is of crucial importance to the proper functioning of the extruder. If material transport instabilities occur as a result of improper screw geometry, even the most sophisticated computerized control system cannot solve the problem. For this purpose, characteristics design on helix angle of the extruder screw. This paper presents strength of the screw flight, optimum helix angle versus dimensionless down channel pressure gradient, optimum helix angle versus the power law index in simultaneous optimization, volumetric efficiency versus helix angle at various number of flights and power consumption versus helix angle in the barrel of screw extruder.