• Title/Summary/Keyword: injection compression molding

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An Optimum Design of Replication Process to Improve Birefringence, Radial-Tilt and Land-Groove Structure in DVD-RAM Substrates (DVD-RAM 기판의 복굴절, Radial-Tilt 및 전사성 향상을 위한 사출압축성형공정 최적화)

  • Gang, Sin-Il;Seong, Gi-Byeong;Lee, Nam-Seok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.4
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    • pp.637-643
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    • 2002
  • The objective of this study is to provide a simple methodology to find optimum processing conditions to fabricate sub-micron structured DVD-RAM substrates with superb optical and geometrical properties. It was fecund that the birefringence, which is regarded as one of the most important optical properties for an optical disk, was very sensitive to the mold wall temperature history. Also, the integrity of the replication, represented by the land-groove structure and the radial tilt were influenced by the mold temperature and the compression pressure. A set of optimum conditions were obtained by applying Design of Experiment and the objective functions composed of three different objectives.

ULTRASIM$^R$ Integrative Simulation Technology on the Development of Automotive Plastic Parts

  • Jae, Hyung-Ho;De Matos, Zeidam Rachib;Kim, Min-Oug;Glaser, Stefan;Wuest, Andreas
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.04a
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    • pp.132-137
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    • 2012
  • To enhance the CAE accuracy, the definition of material behavior is one of key influence on the result. In case of plastic material with fiber reinforcement, the anisotropic material behavior should be taken into account to increase of CAE accuracy. BASF has developed an innovative CAE tool, ULTRASIM$^R$, which is capable of generating material models of thermoplastic materials for structural simulation. ULTRASIM$^R$, not only the glass fiber orientation effect, but also the weld line effect, tensile-compression anisotropy, strain rate effect are combined in a non-linear material law, which will be evaluated in a unique failure criterion, thus resulting in an highly accurate CAE approach.

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Permeation Property of Ionomer Film with New Multifunctional Ionic Site (다관능기를 도입한 아이오노머 필름의 기체투과 특성)

  • Lee, Bo-Mi;Jeong, Sam-Bong;Nam, Sang-Yong
    • Korean Journal of Materials Research
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    • v.22 no.5
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    • pp.227-236
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    • 2012
  • Ionomer is a thermoplastic that is composed of covalent bonds and ionic bonds. It is possible to use this material in processes such as injection molding or extrusion molding due to the material's high oil resistance, weatherproof characteristics, and shock resistance. In this study, a new ionomer having a multifunctional group was prepared by a stepwise neutralization system with the addition of acidic and salt additives. In step I, to increase the contents of the multifunctional group and the acid degree in ethylene acrylic acid (EAA), MGA was added to the ionomer resin (EAA). A new ionomer was prepared via the traditional preparation method of the ionic cross-linking process. In step II, metal salt was added to the mixture of EAA and MGA. The extrusion process was performed using a twin extruder (L/D = 40, size : ${\varphi}30$). Ionomer film was prepared for evaluation of gas permeability by using the compression molding process. The degree of neutralized and ionic cross-linked new ionomer was confirmed by FT-IR and XRD analysis. In order to estimate the neutralization of the new ionomer film, various properties such as gas permeation and mechanical properties were measured. The physical strength and anti-scratch property of the new ionomer were improved with increase of the neutralization degree. The gas barrier property of the new ionomer was improved through the introduction of an ionic site. Also, the ionic degree of cross-linking and gas barrier property of the ionomer membrane prepared by stepwise neutralization were increased.

Effects of MWCNT type and flow type on the electrical conductivity of polycarbonate/MWCNT nanocomposites (MWCNT종류와 유동 형태가 폴리카보네이트/MWCNT 나노복합체의 전기전도도에 미치는 영향)

  • Bui, Duc Nhat;Son, Younggon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.9
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    • pp.13-19
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    • 2018
  • Effects of multiwall carbon nanotube (MWCNT) type and flow type (shear and elongational flow) on the electrical conductivity of polycarbonate (PC)/ MWCNT nanocomposites were investigated. Two different MWCNTs produced a huge difference in electrical conductivity in an injection molded PC/MWCNT nanocomposite. It was observed that MWCNTs having a higher aspect ratio provide much lower electrical conductivity in injection molded PC/MWCNT nanocomposites while the conductivities of compression molded samples from two different MWCNTs were the same. We found that this is due to a difference in the deformability of the two MWCNTs. As the aspect ratio of the MWCNT increases, the orientation of MWCNT by the external force becomes easier and the conductive path diminishes. Consequently the conductivity of the nanocomposites decreases. Nanocomposite samples prepared at a higher extensional rate and shear rate showed lower electrical conductivity. This is also attributed to the flow induced orientation and reduced conductive path of the MWCNTs. The experimental results were discussed in relation to variation in the tube-tube contact due to the change of the MWCNT orientation.

Improving Charge Injection Characteristics and Electrical Performances of Polymer Field-Effect Transistors by Selective Surface Energy Control of Electrode-Contacted Substrate (에폭시 개질 한 다관능 아크릴레이트를 포함하는 충격 저항성이 향상된 불포화폴리에스터 SMC (Sheet Molding Compound) 소재제조 및 그의 물성연구)

  • Jang, Jeong Beom;Kim, Taehee;Kim, Hye Jin;Lee, Wonjoo;Seo, Bongkuk;Kim, Yongsung;Kim, Changyoon;Lim, Choong-Sun
    • Journal of Adhesion and Interface
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    • v.21 no.3
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    • pp.101-106
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    • 2020
  • In this study, epoxy-modified acrylate was synthesized. The synthesized acrylate was added to the composition for sheet molding compound (SMC) in the range of 5 phr to 15 phr. The prepared SMC prepreg was molded at high temperature and pressure to produce a glass fiber reinforced composite. Physical properties such as tensile and impact strength of the composite were measured, respectively. Experimental data show that the composite with 5 phr of synthesized acrylate has 20% improved tensile strength and 12% improved impact strength than that of the reference sample.