• Title/Summary/Keyword: molding stability

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A Study on Properties of the Glass Fiber Reinforced PPS Composites for Automotive Headlight Source Module (자동차 전조등 광원 모듈용 유리섬유강화 PPS 복합재료 특성 연구)

  • Heo, Kwang-Yeol;Park, Sung-Min;Lee, Eun-Soo;Kim, Myung-Soon;Sim, Ji-Hyun;Bae, Jin-Seok
    • Composites Research
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    • v.29 no.5
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    • pp.293-298
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    • 2016
  • In this paper, Glass Fiber Reinforced Thermoplastic (GFRTP) for automotive headlight source module was fabricated by compounding and injection molding using PPS (Poly Phenylene Sulfide) resin with glass fiber which has three cross section (round type, cocoon type, flat type). Tensile, flexural, impact properties were investigated on effect of cross section, glass fiber contents. And it was observed flatness, dimensional stability, fluidity depending on glass fiber cross section. As a result, flat glass fiber reinforced thermoplastic's mechanical properties were most excellent. Also, dimensional stability and flatness showed better results when using flat glass fiber.

Characteristics of Heavy Metal Oxide Glasses in BaO-GeO2-La2O3-ZnO-Sb2O3 System for Infrared Lens (적외선 렌즈용 BaO-GeO2-La2O3-ZnO-Sb2O3계 중금속 산화물 유리의 특성)

  • Sang-Jin Park;Bok-Hyun Oh;Sang-Jin Lee
    • Korean Journal of Materials Research
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    • v.33 no.10
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    • pp.414-421
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    • 2023
  • Infrared radiation (IR) refers to the region of the electromagnetic radiation spectrum where wavelengths range from about 700 nm to 1 mm. Any object with a temperature above absolute zero (0 K) radiates in the infrared region, and a material that transmits radiant energy in the range of 0.74 to 1.4 um is referred to as a near-infrared optical material. Germanate-based glass is attracting attention as a glass material for infrared optical lenses because of its simple manufacturing process. With the recent development of the glass molding press (GMP) process, thermal imaging cameras using oxide-based infrared lenses can be easily mass-produced, expanding their uses. To improve the mechanical and optical properties of commercial materials consisting of ternary systems, germanate-based heavy metal oxide glasses were prepared using a melt-cooling method. The fabricated samples were evaluated for thermal, structural, and optical properties using DSC, XRD, and XRF, respectively. To derive a composition with high glass stability for lens applications, ZnO and Sb2O3 were substituted at 0, 1, 2, 3, and 4 mol%. The glass with 1 mol% added Sb2O3 was confirmed to have the optimal conditions, with an optical transmittance of 80 % or more, a glass transition temperature of 660 ℃, a refractive index of 1.810, and a Vickers hardness of 558. The possibility of its application as an alternative infrared lens material to existing commercial materials capable of GMP processing was confirmed.

Study on Ultra-precision Grinding of EL-Max Material for Hot Press Molding (핫 프레스 성형용 EL-Max 소재 초정밀 연삭 가공에 관한 연구)

  • Park, Soon Sub;Ko, Myeong Jin;Kim, Geon Hee;Won, Jong Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.12
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    • pp.1267-1271
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    • 2012
  • Demand for optical glass device used for lighting could increase rapidly because of LED lighting market growth. The optical glass devices that have been formed by hot press molding process the desired optical performance without being subjected to mechanical processing such as curve generation or grinding. EL-Max material has been used for many engineering applications because of their high wear resistance, high compressive strength, corrosion resistant and very good dimensional stability. EL-Max is very useful for a glass lens mold especially at high temperature and pressure. The performance and reliability of optical components are strongly influenced by the surface damage of EL-Max during grinding process. Therefore, the severe process condition optimization shall be necessary for the highly qualified EL-Max glass lens mold. To get the required qualified surface of EL-Max, the selection of type of the diamond wheel is also important. In this paper, we report best grinding conditions of ultra-precision grinding machining. The grinding machining results of the form accuracy and surface roughness have been analyzed by using Form Talysurf and NanoScan.

Optimization of Process Parameters of Die Slide Injection by Using Taguchi Method (다구치 법을 통한 다이슬라이드식 사출성형의 공정파라미터 최적화)

  • Jeong, Soo-Jin;Moon, Seong-Joon;Jeoung, Sun-Kyoung;Lee, Pyoung-Chan;Moon, Ju-Ho
    • Korean Chemical Engineering Research
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    • v.50 no.2
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    • pp.264-269
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    • 2012
  • Die slide injection marvelously reduces the cost and time in processing plastic products because they can simplify the conventional process through eliminating additional process. However, this process must resolve some defects like whitening, resin infiltration, blowhole, resin overflow, etc. In this study, the process parameters of the injection molding are optimized by using the finite element method and Taguchi method. The injection molding analysis is simulated by employing the Moldflow insight 2010 code and the 2nd injection is by adopting the Multi-stage injection code. The process parameters are optimized by using the $L_{16}$ orthogonal array and smaller-the-better characteristics of the Taguchi method that was used to produce an airtight container (coolant reservoir tank) from polypropylene (PP) plastic material.rodanwhile, the optimum values are confirmed to be similar in 95% confidence and 5% significance level through analysis of variance (ANOVA). rooreover, new products and old products were compared by mdasuring the dimensional accuracy, resulting in the improvement of dimensional stability more than 5%.

A study on Resin Filling Analysis and Experiment by VAP and VaRTM Processes (VaRTM과 VAP 공정의 수지 충진실험 및 해석에 관한 연구)

  • Dong-Hwan Yoon;Kyeong-Ho Seo;Yu-Jung Kwon;Jin-Ho Choi
    • Composites Research
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    • v.36 no.5
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    • pp.310-314
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    • 2023
  • VaRTM(Vacuum assisted resin transfer molding) and VAP(Vacuum assisted process) processes are a type of RTM(Resin transfer molding) process, and are typical out-of-autoclave (OOA) processes that can manufacture large structures at low cost. In this paper, a resin filling test was conducted to compare the VaRTM and VAP processes, and the filling process and dimensional stability were compared. In addition, an analysis method to simulate the filling process was developed, and a dielectric sensor was used to detect the flow front of the resin, which was compared with the analysis results. From the resin filling test, the total filling time of the composite plate was measured to be 48 minutes for the VAP process and 145 minutes for the VaRTM process, and the filling time by the VAP process was reduced by about 67%. In addition, it was confirmed that the VAP process was superior to the VaRTM process in the thickness control ability and uniformity of the composite plate.

Development of large-capacity stack mold for the high-performance household case (고기능성 생활용기 성형을 위한 대용량 스택금형 개발)

  • Shin, Jang-Soon;Kim, Eu-Jin;Jung, Gui-Jae;Hwang, Soon-Hwan;Heo, Young-Moo;Yoon, Gil-Sang;Jung, Woo-Chul;Seo, Tae-Il
    • Design & Manufacturing
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    • v.2 no.3
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    • pp.28-31
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    • 2008
  • In recent, the demand of high-productivity injection mold is increased because of the growth of international packaging market which is induced by an increase of population. The increase of productivity leads to the large-capacity injection molding machine and peripheral devices. For solving this problem, the stack mold which is based on the exsiting machine and device has researched in advanced countries actively. In this paper, as the preliminary research of stack mold development, the stack mold which has 2 level ${\times}4$ cavity was designed and fabricated. Besides, the motion and structural analysis were performed to verify the stability of developed stack mold.

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Analysis of the change in appearance according to the hardening method of leather (가죽의 경화방법에 따른 외형변화 분석)

  • Youshin, Park
    • Journal of Fashion Business
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    • v.26 no.5
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    • pp.122-134
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    • 2022
  • This study is conducted on hardening leather with improved firmness and stability of shape, based on research on types and thickness of leather. The purpose of this study is to test the physical properties of the leather for molding to prepare the foundation for leather molding based on the test results using four methods by thickness of Vegetable and Split. The tests were conducted using a total of five leather types, including three types of vegetable leathers and two types of split, by thickness. Based on the testing method for leathers in KS M 6882, the tests were performed at 27℃ with relative humidity of 65±20%. The samples were prepared with cowhide, size 9cm× 2cm. The measurement parameters are length and width. thickness, volume, mass, density. Regarding the hardening treatment method, changes in appearance and major physical characteristics of leather were reviewed by soaking in hot water, dry heating, hammering, waxing, and olive oil coating. The study results are as follows. In planar works, it is judged that hardening work using a hammer is more suitable for stiffness or density in order to prevent easy breakage with adult muscle density, rather than boiling water or baking. In conclusion, there is no curling, soot, or breaking phenomenon, and the densest curing method is 50℃ for 20 sec of V2 and 75℃ for 60 sec of V2 in boiling water. The combination of paraffin treatment improve waterproof and quality.

Effect of Alkyl Ketene Dimer(AKD) on Red Algae Reinforced Biocomposites (AKD 처리한 홍조류섬유 보강 바이오복합재료의 특성)

  • Lee, Min-Woo;Park, Dong-Hui;Seo, Yung-Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.43 no.2
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    • pp.66-71
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    • 2011
  • Biocomposites were fabricated with biodegradable polymers and natural fibers. Biocomposites have benefits of low cost, low density, and biodegradability over inorganic fiber composite, and give comparable strength properties. Hydrophobic polymer used for sizing in paper industry, AKD (Akenyl Keten Dimer), was applied to natural fibers, red algae fibers (RAF) in this study, to make fiber surfaces more compatible to hydrophobic nature of matrix polymers. Composites with RAF, kenaf, glass fibers, and carbon fibers have been fabricated by a compression molding method and their thermo-mechanical properties have been studied. Also, the thermal dimensional stability test was done from at 30 to $100^{\circ}C$. The storage moduli and the thermo-mechanical stabilities of polypropylene and poly lactic acid based biocomposites were improved by reinforcing with the RAF and much more with AKD treated fibers. Dimensional stability of biocomposite was also markedly improved by AKD pretrement on RAF.

A Quality Stability Estimation of Shock-absorber Tube for automatic drawer (자동서랍함용 완충기 튜브의 품질 안정성 예측)

  • Son, Jae-Hwan;Kim, Young-Suk;Han, Chang-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.7
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    • pp.2919-2924
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    • 2011
  • The automatic drawer is used to absorb the movement shock and adjust its velocity when it opens and closes. The tube in shock-absorber is the cylindrical case which surrounds its parts and is made of acetal. The purpose of this study is to determine the quality stability of the tube in the shock-absorber in injection molding process. The tube which had been manufactured in the process with 4 cavity cooling unit was used. In this study, the analysis and test are carried out to determine its quality stability. Which are the quality analysis with numerical simulation and performance tests of the tube compared with one of foreign make. It is calculated that the injection press is 87.6 MPa and the deflections in X, Y, Z directions are ranged in 0.07~1.00 mm. When the researched tube is compared with the foreign made tube, the maximum bending compressive load is 231 kgf higher, average axial compressive load is 0.05 kgf higher, and the roughness(Ra) on the inner surface is $0.02\;{\mu}m$. lower. In the result, it is known that the quality of researched tube in injection mold process is stable and its performance is superior.

Kinetics of Thermal Degradation of Polypropylene/Nanoclay/Wood Flour Nanocomposites

  • Mohan, D. Jagan;Lee, Sun-Young;Kang, In-Aeh;Doh, Geum-Hyun;Park, Byung-Dae;Wu, Qinglin
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.3
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    • pp.278-286
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    • 2007
  • As a part of enhancing the performance of wood-plastic composites (WPC), polypropylene (PP)/ nanoclay (NC)/ wood flour (WF) nanocomposites were prepared using melt blending and injection molding process to evaluate their thermal stability. Thermogravimetric analysis (TGA) was employed to investigate thermal degradation kinetics of the nanocomposites both dynamic and isothermal conditions. Dynamic scans of the TGA showed an increased thermal stability of the nanocomposites at moderate wood flour concentrations (up to 20 phr, percentage based on hundred percent resin) while it decreased with the addition of 30 phr wood flour. The activation energy $(E_a)$ of thermal degradation of nanocomposites increased when nanoclay was added and the concentration of wood flour increased. Different equations were used to evaluate isothermal degradation kinetics using the rate of thermal degradation of the composites, expressed as weight loss (%) from their isothermal TGA curves. Degradation occurred at faster rate in the initial stages of about 60 min., and then proceeded in a gradual manner. However, nanocomposites with wood flour of 30 phr heated at $300^{\circ}C$ showed a drastic difference in their degradation behavior, and reached almost a complete decomposition after 40 min. of the isothermal heating. The degree of decomposition was greater at higher temperatures, and the residual weight of isothermal degradation of nanocomposites greatly varied from about 10 to 90%, depending on isothermal temperatures. The isothermal degradation of nanocomposites also increased their thermal stability with the addition of 1 phr nanoclay and of wood flour up to 20 phr. But, the degradation of PP100/NC1/MAPP3/WF30 nanocomposites with 30 phr wood flour occurs at a faster rate compared to those of the others, indicating a decrease in their thermal stability.