Moldability improvement in microinjection molding via film lamination

2021 ◽  
pp. 096739112098650
Author(s):  
Dah Hee Kim ◽  
Young Seok Song
Keyword(s):  
Heat Transfer ◽  
Light Guide ◽  
Wall Slip ◽  
Skin Layer ◽  
Pattern Transfer ◽  
Plastic Plate ◽  
Resin Infusion ◽  
Microinjection Molding ◽  
Insulation Effect ◽  
Thin Plastic

The purpose of this study is to integrate a polymeric film onto a mold to impede thermal heat transfer during resin infusion. A thin plastic plate was fabricated by using microinjection molding. A polyimide (PI) film was laminated onto a mold in an effort to produce a thin light guide plate (LGP). The film could decelerate the solidification of molten polymer in the cavity of mold and enhance the wall slip of resin on the mold. The insulation effect was modeled numerically. The surface roughness and pattern transfer characteristics of the LGP were evaluated. It was found that the fluidity of the resin increased due to the decreased skin layer during mold filling. The results showed that the strategy proposed in this study could help decrease the thickness of LGP effectively when manufacturing the part via injection molding.

Investigation of Hydrodynamics and Heat Transfer Effects due to Light Guides in a Column Photobioreactor

2013 ◽  
Author(s):  
Caitlin Gerdes ◽  
Taylor N. Suess ◽  
Gary A. Anderson ◽  
Stephen P. Gent
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Mass Transfer ◽  
Temperature Distribution ◽  
Light Guide ◽  
Flow Patterns ◽  
Light Penetration ◽  
Algae Growth ◽  
Computational Fluid Dynamics Cfd ◽  
Light Guides

Proper light penetration is an essential design consideration for effective algae growth in column photobioreactors. This research focuses on the placement of light guides within a photobioreactor (PBR), and the effect they have on heat transfer, mass transfer, bubble and fluid flow patterns, and mixing. Studies have been done on a rectangular column photobioreactor (34.29 cm long × 15.25 cm wide × 34.29 cm tall) with two light panels along the front and back of the PBR. A bubble sparger is placed along the center of the bottom length of the PBR with both height and width of 1.27 cm and a length of 33.02 cm. Different configurations and numbers of light guides (1.27 cm diameter) running horizontally from the front to the back of the PBR are modeled using the Computational Fluid Dynamics (CFD) software Star-CCM+. It is hypothesized that the addition of light guides will change the flow pattern but not adversely affect the heat or mass transfer of the carbon dioxide bubbles within the PBR. Potential concerns of light guide placement include inhibiting the flow of the carbon dioxide bubbles or creating regions of high temperature, which could potentially kill the algae. Benefits of light guides include increased light penetration and photosynthesis within the PBR. Five different light guide setups are tested with the carbon dioxide bubbles and water modeled as a turbulent multiphase gas-liquid mixture. The near wall standard k-epsilon two layer turbulence model was used, as it takes into account the viscosity influences between the liquid and gaseous phases. Eight different bubble volumetric flow rates are simulated. The bubble flow patterns, temperature distribution, Nusselt number, Reynolds number, and velocity are all analyzed. The results indicate square arrays of light guides give the most desirable velocity distribution, with less area of zero velocity compared to the staggered light guide setup. Temperature distribution is generally even for all configurations of light guides.

Thermal insulation effect of green façades based on calculation of heat transfer and long wave infrared radiative exchange

Measurement ◽  
2021 ◽  
pp. 110555
Author(s):  
Ratih Widiastuti ◽  
Juliana Zaini ◽  
Wahyu Caesarendra ◽  
Georgios Kokogiannakis ◽  
Siti Nurul Nadia Binti Suhailian
Keyword(s):  
Heat Transfer ◽  
Thermal Insulation ◽  
Long Wave ◽  
Insulation Effect ◽  
Long Wave Infrared ◽  
Radiative Exchange

26‐4: Late‐News Paper: Super‐Light Smart Glasses Using a Thin Plastic Light Guide Plate

2020 ◽  
Vol 51 (1) ◽  
pp. 383-386
Author(s):  
Shigenobu Hirano ◽  
Naoki Nakamura ◽  
Masahiro Itoh ◽  
Yoshifumi Sudoh ◽  
Shun Okazaki ◽  
...  
Keyword(s):  
Light Guide ◽  
Smart Glasses ◽  
Light Guide Plate ◽  
Guide Plate ◽  
Thin Plastic ◽  
Late News

Effects of Wall Slip on Convective Heat Transfers of Giesekus Fluid in Microannulus

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Mehdi Moayed Mohseni ◽  
Gilles Tissot ◽  
Michael Badawi
Keyword(s):  
Heat Transfer ◽  
Shear Stress ◽  
Convective Heat ◽  
Slip Flow ◽  
Critical Shear Stress ◽  
Wall Slip ◽  
Outer Wall ◽  
Bulk Temperature ◽  
Brinkman Number ◽  
Thermal Boundary Conditions

Abstract Convective heat transfer and effect of nonlinear wall slip are studied analytically in concentric microannulus for viscoelastic fluids obeying the Giesekus constitutive equation. Laminar, thermally, and hydrodynamically fully developed flow is considered. A nonlinear Navier model with nonzero slip critical shear stress is employed for the slip equation at both walls. Critical shear stress will cause three slip flow regimes: no slip condition, slip only at the inner wall, and slip at both walls. Thermal boundary conditions are assumed to be peripherally and axially constant fluxes at the walls. Governing equations are solved to obtain temperature profiles and Nusselt number and effects of slip parameters, elasticity, and Brinkman number are discussed. Two regimes are compared when slip occurs at both walls or only at the inner wall. The results indicate that by increasing slip effect and elasticity, heat transfer between wall and fluid is enhanced, but it decreases by increasing Brinkman number. In the case where the heat flux is dominant in the outer wall, the inner wall Nusselt curve shows a singularity for a critical Brinkman number because at this Brinkman number the bulk temperature will be equal to the wall temperature.

Flatness and microstructure of a light guide plate fabricated by microinjection molding

2012 ◽  
Vol 53 (1) ◽  
pp. 212-218 ◽  
Author(s):  
Yun-Ho Lin ◽  
Chiung-Fang Huang ◽  
Hsin-Chung Cheng ◽  
Yi Lin ◽  
Jeou-Long Lee ◽  
...  
Keyword(s):  
Light Guide ◽  
Microinjection Molding ◽  
Light Guide Plate ◽  
Guide Plate

scholarly journals UNSTEADY MHD FLOW OF RADIATING CASSON FLUID THROUGH A PERMEABLE CHANNEL WITH SLIP, BUOYANCY FORCE AND HEAT SOURCE

2020 ◽  
Vol 50 (4) ◽  
pp. 315-320
Author(s):  
Om Prakash Verma ◽  
Oluwole Daniel Makinde ◽  
R. L. Monaledi
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Skin Friction ◽  
Buoyancy Force ◽  
Fluid Velocity ◽  
Vertical Channel ◽  
Wall Slip ◽  
Mhd Flow ◽  
Casson Fluid ◽  
Left Wall

Analytical investigation is performed into an unsteady Magnetohrodynamics mixed convective Casson fluid flow and heat transfer characteristics with thermal radiation, wall slip, heat source and buoyancy force in a permeable vertical channel. The fluid is injected into the left wall of the channel and sucked out at right wall. The governing momentum and energy balance equations are achieved and tackled analytically. The effects of numerous thermophysical parameters on the temperature profiles, velocity, Nusselt number as well as skin friction are presented graphically and discussed qualitatively. The results show that a temporal decline in the pressure gradient causes both the temperature and fluid velocity to decrease. Moreover, the enhancement in heat transfer due to wall injection/suction also causes the skin friction to decrease.

scholarly journals HEAT TRANSFER IN VISCOPLASTIC BOUNDARY-LAYER FLOW FROM A VERTICAL PERMEABLE CONE WITH MOMENTUM AND THERMAL WALL SLIP: NUMERICAL STUDY

2018 ◽  
Vol 49 (3) ◽  
pp. 189-204 ◽  
Author(s):  
Annasagaram Subba Rao ◽  
V. Ramachandra Prasad ◽  
V. Naga Radhika ◽  
O. Anwar Beg
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Numerical Study ◽  
Wall Slip ◽  
Layer Flow
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