• Title, Summary, Keyword: Injection Molding

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Stress Distribution in Microvascular Anastomotic Coupler (AnaFix®) Micropins with Respect to the Fillet Radius (필렛효과에 따른 미세혈관 문합커플러(AnaFix®) 마이크로핀의 응력분포)

  • Jee, Dae-Won;Kim, Cheol-Woong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.11
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    • pp.1139-1145
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    • 2011
  • An automated anastomotic ring-pin system consisting of both the anastomotic ring-pin system and the coupler device has eliminated the drawbacks of the suture method. High density polyethylene (HDPE), a material with outstanding biocompatibility and injection molding capability, was used in the ring. SUS316 stainless steel, Ti-6Al-4Nb, Ti-6Al-4V, and unalloyed titanium were used in FEM simulations of the micropin. The authors categorized the microvascular anastomotic ring micropins into short neck (SN) and long neck (LN) groups in order to evaluate the effect of the micropin's fillet radius and neck length on the von Mises stress. The micropins were further divided into those with and without fillet. On the basis of the fillet radius rate (FRR), which represents the rate of change in the von Mises stress with respect to the availability and shape of the fillet, and the neck length rate (NLR), which represents the rate of change in the von Mises stress with respect to changes in the length of the neck within the fillet shape, it can be concluded that the SN-3 neck design is the most stable.

A Study on the Characteristics of IR/CR Rubber Blends by Surface Treatment with Chlorine (염소의 표면처리에 따른 IR 및 CR Blend의 특성 연구)

  • Park, Ji-Hye;Lee, Chang-Seop;Park, Hyun-Ho
    • Journal of the Korean Chemical Society
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    • v.54 no.6
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    • pp.749-754
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    • 2010
  • In this study, rubber vulcanization property, change in physical property, morphology and chemical characteristics of blended rubber depending on various IR/CR ratio were investigated for the purpose of the improvement of material property and durability. The effect of surface treatment by chlorine on the friction coefficient was also studied with various conditions of surface treatment. In terms of vulcanization property, as the amount of CR content increased, the speed of cure was decreased, while the density of crosslinking stayed constant. It means hardness and modulus were increased as the CR content increased. It is related to change in cure property and mechanical strength was improved by the effect of crystallization reaction. In the aging property, as the CR content increases, the changed amount of basic properties were decreased, which acts as a reducing factor in change of aged property by complementing weak point in mechanical property. It was found that the degree of property change for surface treated samples were reduced. According to the microscopic result, the degree of surface dispersion on rubber blends was increased by increasing CR content. Rubber surface showed uniform direction in pattern with increased smoothness and luster by treatment with chlorine. The degree of rubber reforming was measured by the remaining amount of chlorine and the friction coefficient was dependent on the amount of chlorine combined with rubber. In the initial stage of surface treatment, from 10 to 40 phr, the friction coefficient of specimen was rapidly reduced. However, as the concentration of chlorine solution increased, the change in friction coefficient was decreased.

Fabrication and Performance Evaluation of MR-16 Lamp Series with Narrow Angular Distribution of Luminous Intensity Using an Aspherical Planar-convex 2×2 Fly-eye Lens Type (평면-비구면 2×2 fly-eye 렌즈형태의 2차 렌즈를 사용한 고효율의 좁은 배광각을 갖는 MR-16 램프 시리즈 제작 및 성능평가)

  • Chu, Kyung-duk;Ryu, Jae Myung;Hong, Chun-Gang;Jeong, Youn Hong;Jo, Jae Heung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.8
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    • pp.25-33
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    • 2017
  • This paper reports the optical design of the MR-16 lamp series with a LED second lens and an aspherical plano-convex lens suitable for a simple and rapid injection molding fabrication method. The fabrication and performance evaluation of the MR-16 lamp series, which was designed with a narrow angular distribution of luminous intensity, were conducted to replace halogen lamps with LED lamps. Four types of LED lamps were fabricated, which have angular distributions of luminous intensity of $22.4^{\circ}$, $31.1^{\circ}$, $37.3^{\circ}$, and $59.9^{\circ}$ and luminous efficiencies of 76.5 lm/W, 75.2 lm/W, 72.0 lm/W, and 77.8 lm/W, respectively, while their spreading angles with an illuminance uniformity of 81% were $3^{\circ}$, $15^{\circ}$, $22^{\circ}$, and $49^{\circ}$, respectively. After eliminating a yellow tail of the LED lamps using a diffusion sheet, the angular distributions of the luminous intensity were measured to be $20.8^{\circ}$, $31.5^{\circ}$, $37.8^{\circ}$, and $68.7^{\circ}$.

Stable lateral-shearing interferometer for in-line inspection of aspheric pick-up lenses (생산 라인에서의 광 Pick-up용 비구면 대물 렌즈 측정을 위한 안정된 층밀리기 간섭계)

  • 조우종;김병창;김승우
    • Korean Journal of Optics and Photonics
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    • v.8 no.3
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    • pp.189-193
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    • 1997
  • Aspheric pick-up lenses are increasingly used in consumer products such as computer and multimedia, as their mass production has become possible owing to the injection molding process. However still much work needs to be done for more effective manufacture of aspheric lenses, one area of which is the in-line inspection of produced lenses. In this paper, we present a lateral-shearing interferometer that has specially been designed to have a high immunity to external vibration and atmospheric disturbance. The interferometer comprises four prisms. They are directly attached to each other using an immersion oil so that relative sliding motions between the prisms are allowed. Their relative displacement can readily generate necessary lateral-shearing and phase-shifting to determine the wavefront of the beam collimated by the lens under inspection. A special phase-measuring algorithm of arbitrary-bucket is adopted to compensate the phase-shifting error caused by the thickness reduction in the immersion oil. Zernike polynomial fitting has done for determinating quantitative aberration of aspheric pick-up lenses. The interferometer built in this work is robust to external mechanical vibration and atmospheric disturbance so that experimental results show that it has a repeatability of less than λ/100.

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A Study on the Mechanical Properties Experiment for Architectural Application of Polyamide-12 MJF 3D Printing Material - Focusing on the Change in Tensile Properties According to the 3D Printing Orientation - (MJF 3D 프린팅 기반 폴리아미드-12 소재의 건축적 활용을 위한 기계적 특성 실험에 관한 연구 - 출력 방향에 따른 인장 특성 변화를 중심으로 -)

  • Park, Sangjae;Yoo, Seungkyu;Kim, Munhwan;Kim, Jaejun
    • Korean Journal of Construction Engineering and Management
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    • v.21 no.6
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    • pp.95-102
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    • 2020
  • The number of use cases in machinery, aviation, and other industries that manufacture precise parts is increasing, and the construction industry is also increasingly using 3D printing technology. Although various materials for 3D printing are currently being developed and utilized, 3D printing manufacturing has a problem that the mechanical properties of the product may change when compared with conventional manufacturing methods such as injection and molding. This paper verifies the effect of the printing orientation on the mechanical properties of the product in the manufacture of PA12 material and providing basic data on the practical use of the materials as building subsidiary materials and structural materials. The results of the experiment showed that the product printed in the orientation of 0° showed the lowest overall strength and elongation rate, and the product printed in the orientation of 45° showed the highest figure. Overall, tensile strength and yield strength increased between 0° and 45°, and tended to decrease somewhat at 45° to 90°.

Mechanical Properties of Wood Flour-Polypropylene Composites: Effects of Wood Species, Filler Particle Size and Coupling Agent (목분-폴리프로필렌 복합재의 기계적 특성: 목재수종, 충진제 입자크기 및 상용화제의 영향)

  • Kang, In-Aeh;Lee, Sun-Young;Doh, Geum-Hyun;Chun, Sang-Jin;Yoon, Seung-Lak
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.6
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    • pp.505-516
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    • 2009
  • The effects of wood species, particle size of wood flours and coupling treatment on the mechanical properties of wood plastic composites (WPC) are investigated in this study. Chemical components of wood flour from 3 different wood species were analyzed by the chemical analysis. Wood flours of 40~60 mesh and 80~100 mesh were manufactured from Larix (Larix kaempferi Lamb.), Quercus (Quercus accutisima Carr.), and Maackia (Maackia amuresis Rupr. et Maxim). The wood flours were reinforced into polypropylene (PP) by melt compounding and injection molding, then tensile, flexural, and impact strength properties were analyzed. The order of alpha-cellulose content in wood is Quercus (43.6%), Maackia (41.3%) and Larix (36.2%). The order of lignin content in wood is Larix (31.6%), Maackia (24.7%), and Quercus accutisima (24.4%). The content of extractives in wood is in the order of Larix (8.5%), Maackia (4.4%), and Quercus accutisima (3.9%). As the content of alpha-cellulose increases and the lignin and extractives decreases, tensile and flexural strengths of the WPC increase. At the same loading level of wood flours, the smaller particle size (80~100 mesh) of wood flours showed highly improved tensile and flexural strengths, compared to the larger one (40~60 mesh). The impact strength of the WPC was not significantly affected by the wood species, but the wood flours of larger particle size showed better impact strengths. The addition of maleated polypropylene (MAPP) provided the highly improved tensile, flexural and impact strengths. Morphological analysis shows improved interfacial bonding with MAPP treatment for the composites.