Ping‐Yao Wu

ITRI International

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Ta‐Jo Liu

National Tsing Hua University

Jing‐Pin Pan

Industrial Technology Research Institute

Fang‐Ho Lin

National Tsing Hua University

C. C. Liu

National Tsing Hua University

Carlos Tiu

Institute of Chemical Engineering

Po‐Ju Chen

Texas A&M University

Lee‐May Huang

National Tsing Hua University

Hung-Chih Chen

Institute of Biomedical Sciences, Academia Sinica

Chi-Feng Lin

National Pingtung University of Science and Technology

Yu-Rong Chang

Zhongnan Hospital of Wuhan University

Cooperative Institutions

National Tsing Hua University

Industrial Technology Research Institute

National Taiwan University

ITRI International

National Yang Ming Chiao Tung University

Feng Chia University

National Cheng Kung University

National Taiwan Normal University

National Applied Research Laboratories

Atomic Energy Council

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Extrusion die design for slowly reacting materials

Polymer Engineering and Science (1997)

Jing‐Pin Pan Ping‐Yao Wu Ta‐Jo Liu

Abstract The flow distribution of slowly reacting polymeric materials inside an extrusion die was analyzed by lubrication theory. The viscosity of the polymeric liquid was assumed to be time‐dependent owing to chemical reaction. Three types of extrusion dies were considered: a T‐die, a linearly tapered coat‐hanger die with a choker bar, and a curvilinearly tapered coat‐hanger die. It was found that the T‐die is not suitable to deliver the polymeric liquid films, whereas the two coat‐hanger dies can deliver the polymeric liquid films with acceptable flow uniformity and residence time distribution.

Extrusion moulding

Reactive extrusion

Bar (unit)

10.1002/pen.11728

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Citations (9)

Drying‐induced birefringence of polyimide optical films

AIChE Journal (2009)

Po‐Ju Chen Ta‐Jo Liu Ping‐Yao Wu Chi‐Fu Tseng Chyi‐Ming Leu

Abstract Drying‐induced birefringence of polyimide film was investigated. The polyimide solutions were coated and dried on two different types of substrates and then removed for optical measurements. The operating window, which was a region for stable and uniform film formation, was determined experimentally. The out‐of‐plane birefringence (OPBR) was found to increase with decreasing dry film thickness, and the increase became more significant for films less than 10 μm thick. The experimental OPBR results were compared with the predictions of two theoretical models. The results agreed reasonably well with the one‐dimensional model of Lei et al. ( J Appl Polym Sci . 2001;81:1000‐1013). On the other hand, a simple viscoelastic model, which is an extension of the elastic model of Croll ( J Appl Polym Sci . 1979;23:847‐858), could provide clear physical insight, but its applicability was somewhat limited. The effects of several variables such as elasticity number, solidification concentration, yield stress, and mass transfer rate on OPBR were examined. © 2009 American Institute of Chemical Engineers AIChE J, 2010

Elasticity

10.1002/aic.12022

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Citations (7)

Optical-Electronic Properties of Carbon-Nanotubes Based Transparent Conducting Films

Advances in Chemical Engineering and Science (2013)

Kuan-Ru Chen Hsiu-Feng Yeh Hung-Chih Chen Ta‐Jo Liu Shu–Jiuan Huang

Three coating methods (slot, dip and blade coatings) were used separately to coat a well-dispersed single-wall carbonnanotube (SWCNT) solution on polyethylene terephthalate (PET) film, and the resulting optical and electronic properties were measured and compared. It was found that the sheet resistance and the transparency of the SWCNT coated film decreased as the coating speed increased for dip and blade coatings, but were independent of the coating speed for slot coating. All three coating methods were able to produce transparent conductive film with transparency above 85% and sheet resistance close to 1000 ohm/sq. For industrial production, the slot die coating method appears to be more suitable in terms of high coating speed and uniformity of optical and electronic properties.

Optical transparency

10.4236/aces.2013.31013

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Citations (15)

TECHNICAL NOTE: NATURAL CONVECTION OF NON-NEWTONIAN LIQUIDS IN A CYLINDRICAL ENCLOSURE

Numerical Heat Transfer Part A Applications (1994)

Ping‐Yao Wu Ta‐Jo Liu Hsu-Ming Chang

ABSTRACT The Galerkin finite element method was applied to analyze natural convection of non-Newtonian liquids in a cylinder. The non-Newtonian liquids under consideration were assumed to obey the Carreau model. The effect of four variables, the Rayleigh number (Ra), the Carreau number (Cu), the Pradtl number (Pr) and the flow index (n) on natural convection, was examined.

Carreau fluid

Enclosure

10.1080/10407789408955954

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Citations (6)

Design of an extrusion die with a variable choker bar

Journal of Applied Polymer Science (1994)

Ping‐Yao Wu Ta‐Jo Liu Hsu‐Ming Chang

Abstract A novel approach is proposed to adjust flow nonuniformities caused by production variations from an extrusion die. A mathematical model that is based on the lubrication approximation was developed, and the effect of four types of production variations was examined separately. To each production variation, a specially designed choker bar was constructed and inserted into the extrusion die to correct flow nonuniformities. © 1994 John Wiley & Sons, Inc.

Bar (unit)

Material Flow

10.1002/app.1994.070510605

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Citations (11)

Three minimum wet thickness regions of slot die coating

Journal of Colloid and Interface Science (2006)

Yu-Rong Chang Hsien‐Ming Chang Chi-Feng Lin Ta‐Jo Liu Ping‐Yao Wu

Meniscus

10.1016/j.jcis.2006.11.054

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Citations (85)

Theoretical analysis on extrusion die flow of electronic packaging materials

AIChE Journal (1999)

Jing‐Pin Pan Ta‐Jo Liu Ping‐Yao Wu

Abstract A mathematical model has been developed to describe the extrusion die flow of reactive electronic packaging materials. This model assumes that the flow is 1‐D in the manifold of the die, but the flow obeys the 2‐D Hele–Shaw model in the slot section. A realistic viscosity expression that includes the effects of chemical reaction and heat transfer has been adopted. A linearly tapered coat‐hanger die was selected for illustration and the packaging material was chosen to be the epoxy system. Some example calculations are presented to illustrate the effects of several parameters on the flow distribution. Two optimization approaches were adopted to improve the uniformity of the flow; both the Taguchi method and the method of inserting a specially designed choker bar are applicable. However, using a choker bar appears to be more effective and flexible.

Bar (unit)

Electronic Packaging

10.1002/aic.690450221

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Citations (5)

A simple model for heat transfer inside an extrusion die

Polymer Engineering and Science (1995)

Ping‐Yao Wu Lee‐May Huang Ta‐Jo Liu

Abstract A simple model based on the lubrication approximation has been developed to analyze heat transfer of power‐law fluids inside an extrusion die. This model can effectively predict the influence of temperature variations and other production alterations on flow uniformity. The predictions of this model are compared with those based on three‐dimensional finite element simulation, and the agreement is satisfactory. The optimal design concept can be incorporated into this model so that a specially designed choker bar can be inserted into the extrusion die to reduce flow nonuniformities. The shape of the choker bar is initially suggested by the lubrication model; minor corrections through the three‐dimensional finite element simulation are then introduced so that a choker bar can be properly constructed to eliminate flow nonuniformities.

Bar (unit)

10.1002/pen.760352108

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Citations (15)

Experimental study on tensioned‐web slot coating

Polymer Engineering and Science (2007)

Fang‐Ho Lin C. C. Liu Ta‐Jo Liu Ping‐Yao Wu

Abstract Tensioned‐web slot coating (TWSC) technology was developed in the early 1980s and was considered an efficient method for thin liquid film coating. An experimental study was carried out to investigate the effects of several key parameters on the minimum wet thickness of TWSC. The experiment was performed on a pilot coater with dilute Newtonian poly(vinyl) alcohol (PVA) solutions as test fluids coating on polyethylene‐terephthalate (PET) substrates. It was found that the minimum wet thickness for TWSC was between 0.5 and 1.5 μm, which is much lower than that obtained using conventional slot die coating. The minimum wet thickness was proportional to the tension number T N , which is defined as the ratio of fluid viscous force over web tension. Furthermore, on the basis of the experimental data, two additional dimensionless groups: dimensionless pressure P N and dimensionless surface tension L N were found to be relevant to the performance of TWSC. A universal correlation involving these dimensionless groups as well as the die geometry was used to predict the minimum wet thickness of TWSC. POLYM. ENG. SCI., 47:841–851, 2007. © 2007 Society of Plastics Engineers

Dimensionless quantity

Tension (geology)

10.1002/pen.20764

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Citations (18)

Validity of one‐dimensional equation governing extrusion die flow

AIChE Journal (1997)

Yun‐Wey Yu Ping‐Yao Wu Ta‐Jo Liu

DEPT

10.1002/aic.690431123

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Citations (7)