Thermal contact conductance of selected polymeric materials

Marotta, Egidio; Fletcher, L. S.

doi:10.2514/3.792

Cited by 85 publications

(45 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Marotta and Fletcher 5 showed that the contact conductance at selected polymer-aluminum interfaces also did not follow the trend given by either the elastic or the plastic models for contact conductance. Furthermore, the results of Rhee et al, 8 and Narh and Sridhar 9 show that the contact conductance at conforming plastic-metal surfaces is of the order of 0.125-0.25 ϫ 10 5 W/m 2 -K, which is more than an order of magnitude lower than that reported by Marotta and Fletcher,5 for surfaces that were not specially prepared to be conforming. At such interfaces, the effect of the surface waviness is expected to be a dominant factor in determining the magnitude of contact conductance, 10 resulting in a departure from the established contact conductance models.…”

Section: Introductioncontrasting

confidence: 40%

“…[5][6][7][8][9][10][11][12] Such interfaces are typically between materials of widely varying thermal conductivity. From the perspective of processing and product design applications, metals that are most likely to be used (steels, aluminum) have thermal conductivity in the range of 35-250 W/m-K. 13 Plastics, on the other hand, have thermal conductivity generally in the range of 0.1-0.4 W/m-K, 14 while thermal conductivity of elastomers are in the range 0.5-1.5 W/m-K. Seyed Yagoobi et al 15 studied the thermal contact conductance at a paper-metal interface and showed that the contact conductance was a function of the logarithm of the contact pressure.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Finite size gap effects on the modeling of thermal contact conductance at polymer-mold wall interface in injection molding

Sridhar

Narh

2000

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

Heat transfer in polymer processing by injection molding is affected by the thermal contact conductance at the interface between the polymer and the metal mold. The modeling of thermal contact conductance at such interfaces is simplified by the assumption of an isothermal condition at the two contacting surfaces. In this study we examine the validity of such an assumption for the case of an interface involving plastic (a low thermal conductivity material) and metal (a high thermal conductivity material). The study shows that at such an interface between materials of widely varying thermal conductivity, the conditions at the interface depart from the isothermal assumption, with the heat flux becoming more uniform and the temperature difference varying by a larger magnitude across the contact plane. This effect is more pronounced as the width of the gaps increases for the same area of contact. This suggests that the modeling of the contact conductance should be based on average temperatures for the contacting surfaces.

show abstract

Section: Introductioncontrasting

confidence: 40%

Section: Introductionmentioning

confidence: 99%

Finite size gap effects on the modeling of thermal contact conductance at polymer-mold wall interface in injection molding

Sridhar

Narh

2000

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

show abstract

“…It should be noted, however, that the values of Table II are rather high as stated by Shridhar,20 who found that for PS the value of TCR is around 10 −4 m 2 K W −1 . Shridhar also noted that the value of TCR changes during the injection molding cycle and at the later stages of postfilling approaches the values found by Yu et al 18 Moreover, the values quoted by Marotta and Fletcher 19 were found to be rather high and this was attributed to the waviness of the surface of the samples used in that experimental study. Another problem with Eq.…”

Section: Application Of Pham's Equation In Injection Moldingmentioning

confidence: 55%

“…Measurements of TCR are summarized in Table II along with the calculated values for TCC. 18,19 From a design point of view the cooling channel and the mold should not present a lot of resistance in heat transfer. Table II shows that in some cases TCC is less than 500 W m −2 K −1 , which means that the mold-part resistance is the controlling factor.…”

Section: Application Of Pham's Equation In Injection Moldingmentioning

confidence: 99%

Prediction of cooling time in injection molding by means of a simplified semianalytical equation

Zarkadas

Xanthos

2003

Adv Polym Technol

View full text Add to dashboard Cite

ABSTRACT:A simplified semianalytical equation, used successfully in food freezing/chilling time prediction, is proposed as a potential simple alternative for cooling time prediction in injection molding of polymer parts, amorphous or semicrystalline. This equation is based on a convective boundary condition for the mold-part interface and requires information on the thermal contact resistance (TCR) or thermal contact conductance (TCC) at this interface, as well as information on the initial and final product temperatures, the mold surface temperature, and the thermal properties of the part. Eighty-five data points for four polymers, Polystyrene (PS), Polycarbonate (PC), Polypropylene (PP), and Polyethylene (PE) were generated with C-MOLD TM , a commercial injection molding design software, and the performance of the proposed equation was tested. The % mean error and its standard deviation (SD) in cooling time prediction were, respectively, −11.61 and 2.27 for PS, −6.04 and 2.13 for PC, −7.27 and 6.55 for PP, and −8.88 and 2.93 for PE. It was also shown that the accuracy of PREDICTION OF COOLING TIME IN INJECTION MOLDINGthe proposed equation is not affected significantly by the exact knowledge of the TCC, provided that the latter is not smaller than 1000-2000 W m −2 K −1 . Since in this comparison all necessary temperatures were obtained from C-MOLD TM , methods of using the proposed equation independently were tested. The use of the inlet melt temperature as the initial product temperature increased the % mean error by mostly 1.5% while its SD remained practically the same. By incorporating a literature based heat balance method in the proposed equation, it was possible to use it as a stand-alone predictor of polymer cooling time. The % mean error and its SD calculated this way were, respectively, −9.44 and 0.97 for PS, −9.44 and 0.83 for PC, −14.22 and 5 for PP, and −20.12 and 1.38 for PE. The proposed equation, at least in a preliminary stage, can be used successfully to predict the cooling time of the selected semicrystalline or amorphous polymers with the accuracy being higher for amorphous polymers.

show abstract

“…Material characteristics for the Al ux meter and the polymeric specimen are shown in Table 3 (Refs. [23][24][25].…”

Section: Sample Preparationmentioning

confidence: 99%

Parametric Analysis of Heat Transfer on Multistage Cryogenic Radiator

Couto

Mantelli

Marotta

et al. 2002

Journal of Thermophysics and Heat Transfer

Self Cite

View full text Add to dashboard Cite

A theoretical and experimental parametric study of the heat-transfer phenomena on a multistage passive cryogenic radiator is presented. This investigation was performed in the frame of a cooperative effort between Clemson University and the Federal University of Santa Catarina. Passive cryogenic radiator technology is under development at the Satellite Thermal Control Laboratory at the Federal University of Santa Catarina, where two experimental prototypes have been built and ground tested. The mathematical model, developed to predict the temperature distribution on the radiator stages, was used to study the sensitivity coef cients with respect to the design parameters. The design parameters considered are the radiator stage's surface emissivity, the multilayer insulation effective emissivity, the radiator support's global conductance, and the thermal load over the radiator stages. This sensitivity analysis showed that the thermal joint conductance between the stages and the support structure

show abstract

Thermal contact conductance of selected polymeric materials

Cited by 85 publications

References 10 publications

Finite size gap effects on the modeling of thermal contact conductance at polymer-mold wall interface in injection molding

Finite size gap effects on the modeling of thermal contact conductance at polymer-mold wall interface in injection molding

Prediction of cooling time in injection molding by means of a simplified semianalytical equation

Parametric Analysis of Heat Transfer on Multistage Cryogenic Radiator

Contact Info

Product

Resources

About