• 소성∙가공
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• 제14권3호
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• pp.233-238
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• 2005

Blow molding is divided into three categories, injection stretch blow molding, injection blow molding, and extrusion or direct blow molding. Extrusion blow molding has been studied experimentally to characterize the blowing behavior of parison. Blow conditions such as blowing temperature and cooling time were the experimental variables in this blowing experiment. Wall thickness of the lower part of blow molded sample was thicker than that of the upper part because of the sagging of parison during extrusion process. As temperature increases the wall thickness and the weight of blow molded sample decreased. No thickness variations in the blowing sample were observed according to the cooling time. The lower part of the sample showed high degree of crystallinity compare with the upper part of the sample. Thus the lower part of the sample was strong mechanically and structurally. It was recognized that the uniform wall thickness could not be obtained by only controlling the operational conditions. Parison variator should be introduced to get uniform wall thickness of parison and subsequently produce uniform wall thickness of blow molded product.

• 소성∙가공
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• 제11권8호
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• pp.651-667
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• 2002

Overview of plastics processing is described and the research trend of the processing is also noted. The main manufacturing processes in the plastics industry are injection molding, blow molding, compression molding, transfer molding, extrusion and thermoforming. The principles of those processes have been discussed and molds for shaping operation have been mentioned. References for each process have also been presented.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2001년도 International Conference CALS/EC KOREA
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• pp.105-109
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• 2001

성형의 종류 ◈금속 성형 ㆍ 스탬핑(Stamping) ㆍ 정밀 블랭킹(Fine Blanking) ㆍ 딥 드로잉(Deep Drawing) ㆍ 다이캐스팅(Die Casting) ㆍ 인베스트먼트 주조(Investment Casting) ㆍ 분말 야금(Power Metallurgy) ㆍ 인발(Wire Drawing) ㆍ 압출(Extrusion) ㆍ 단조(Forging) ㆍ ㆍ코이닝(Coining) ㆍ... ◈비금속 성형 ㆍ 사출(Injection) ㆍ 압축(Compression) ㆍ 블로우 성형(Blow Molding) ㆍ 진공 성형(Vacuum Molding) ㆍ 발포 성형(Foam Molding) ㆍ 피복(Encapsulation) ㆍ 회전식(Rotational) ㆍ 주조(Casting) ㆍ 적층(Laminating) ㆍ 압출(Extrusion) ㆍ...(중략)

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제3회 금형가공 심포지엄
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• pp.163-177
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• 2004

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.585-590
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• 1997

Conventional foaming process has defects such as lower mechanical properties than ur~foaming material due to non-uniform cell distribution and environmental pollution problem caused by chemical blowing agency. So, a new foaming process such as Microcelluar plastics has been introduced to use inactive gases as a foaming agency. In order to apply Microcellular plastics for mass production process system such as extrusion, injection molding and blow molding, it needs to predict the change in material properties of polymer according to the amount of meltingas. In Polymer molding applying Microcelluar plastics, the change of viscosity among several material properties is the most important factor. Therefore, this paper is aimed to establish the method which not only finds out but also predicts the change of viscosity of ABS(Acrylonitri1e Butadiene Styrene) resin according to inert gas amount in extrusion molding.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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• pp.212-220
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• 2000

Single flighted screw extrusion is the most cost effective method for the production of film, sheet, pipe and the fundamental step in other processes including blow molding and injection molding. The temperature of polymer melts and injection pressure play a very important role in the injection molding machine. Thermal distortion and displacement of screw by temperature difference and injection pressure difference cause adhesive wear by metal-to-metal contact. In this paper we analyze thermal distortion and stress of screw includes pressure and temperature distributions by finite element analysis to understand dynamic characteristics of screw.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2003년도 학술대회지
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• pp.341-347
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• 2003

Single flighted screw extrusion is the most cost effective method for the production of film, sheet, pipe and the fundamental step in other processes including blow molding and injection molding The temperature and injection pressure in barrel play a very important role in quality of products. Because thermal distortion and displacement of barrel by temperature difference and injection pressure difference cause irregular resine melting and flow. In this paper thermal distortion and stress of barrel includes pressure and temperature distributions by finite element analysis to understand dynamic characteristics of barrel.

• Korea-Australia Rheology Journal
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• 제11권4호
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• pp.305-311
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• 1999

The shear behavior of polymers obtained by means of devices such as capillary and cone-and-plate rheo-meters is commonly used to assess their processing performance and as a characterization tool. However, the number of instances when two polymers have the same shear properties but perform differently during certain types of processing operations (e.g. film blowing and sheet extrusion) indicate that shear properties alone may not be sufficient to characterize polymeric fluids. We begin by defining the kinematics of shear-free or extensional flow and the associated material functions. The extensional and shear behavior of three different types of polyethylene (PE) are then compared to illustrate the points that one cannot ascertain the extensional properties of polymer melts from their shear properties and, furthermore, there may not be a simple relation between properties obtained from one type of extensional flow and those of another type. The kinematics of most processing flows are extensional rather than shear in nature, and , hence, the performance of polymers during processes such as fiber spinning, film casting, film blowing, thermoforming, blow molding, and even extrusion is more readily accounted for through extensional viscosity measurements. Methods for carrying out extensional flow measurements are then reviewed including approximate methods. To illustrate the sensitivity of extensional viscosity measurements to subtle changes in the molecular architecture of PEs, results are presented for samples with a narrow molecular weight distribution but with varying numbers of long chain branches. Finally, constitutive equations which allow one to separate shear and extensional flow behavior are discussed as any attempts to simulate the subtle processing differences between two polymers will require constitutive equations of this nature.