Analysis of thermal contact resistance between polymer and mold in injection molding

Bendada, A.; Derdouri, A.; Lamontagne, Mario; Simard, Y.

doi:10.1016/j.applthermaleng.2003.12.027

Cited by 97 publications

(53 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bendada et al [12] investigated heat transfer in injection moulding over time. They found that the shrinkage of the polymer caused sudden forming of air gaps and thereby sudden changes in heat transfer coefficient, h t .…”

Section: Micro-mouldingmentioning

confidence: 99%

Sealing of polymer micro-structures by over-moulding

Vingaard

Christiansen

2011

Int J Adv Manuf Technol

View full text Add to dashboard Cite

A concept for sealing of polymer microstructures by over-moulding with polystyrene was devised and investigated by both experiments and simulations. The depth to which the melt filled the structure, i.e. a groove in the surface of the insert, before solidification was compared with results from simulations by computational fluid dynamics software.In both experiments and simulations, there was clearly an increase of filling depth with groove width and, especially for wide grooves, with injection temperature. In the simulations, changes in prescribed heat transfer coefficient had the largest effect on filling depth in the narrowest grooves. Around the experimental groove widths, there was good agreement between experiments and simulations. It was concluded that sealing by over-moulding is feasible if the depth/width ratio of the structure is large enough which in this paper is larger than six, i.e. up to several times the filling depth in a corresponding metal or silicon structure.

show abstract

Section: Micro-mouldingmentioning

confidence: 99%

Sealing of polymer micro-structures by over-moulding

Vingaard

Christiansen

2011

Int J Adv Manuf Technol

View full text Add to dashboard Cite

show abstract

“…We have assumed a perfect thermal contact between the melt and the mold surface. This is a reasonable approximation during the initial filling phase when the viscosity is low and thermal contraction of the bulk polymer melt is still minimal [51].…”

Section: Discussionmentioning

confidence: 99%

Hydrogen silsesquioxane mold coatings for improved replication of nanopatterns by injection molding

Hobæk

Matschuk²,

Kafka³

et al. 2015

J. Micromech. Microeng.

View full text Add to dashboard Cite

We demonstrate the replication of nanosized pillars in polymer (cyclic olefin copolymer) by injection molding using nanostructured thermally cured hydrogen silsesquioxane (HSQ) ceramic coatings on stainless steel mold inserts with mold nanostructures produced by a simple embossing process. At isothermal mold conditions, the average pillar height increases by up to 100% and a more uniform height distribution is observed compared to a traditional metal mold insert. Thermal heat transfer simulations predict that the HSQ film retards the cooling of the polymer melt during the initial stages of replication, thus allowing more time to fill the nanoscale cavities compared to standard metal molds. A monolayer of a fluorinated silane (heptadecafluorotrichlorosilane) deposited on the mold surface reduces the mold/polymer interfacial energy to support demolding of the polymer replica. The mechanical stability of thermally cured HSQ makes it a promising material for nanopattern replication on an industrial scale without the need for slow and energy intensive variotherm processes.

show abstract

“…For example, the process parameters are corrected by monitoring the cavity pressure in order to reduce shrinkage and warpage resulting from residual stress inside the plastic parts [1][2][3]. There are many methods of monitoring the physical quantities inside a cavity during the process, including measuring the melt flow front [4][5][6][7][8][9], mold heat flux [10,11], mold temperature [11][12][13][14][15], cavity pressure/ temperature [1,2,[14][15][16][17][18][19][20][21][22][23], and dimensions and properties of the molded part [3,[24][25][26][27]. The sensor types include the frequently used contact type, noncontact type [28][29][30][31], and even a wireless type of sensor [32][33][34][35][36].…”

Section: Introductionmentioning

confidence: 99%

Correlation between runner pressure and cavity pressure within injection mold

Tsai

Lan

2015

Int J Adv Manuf Technol

View full text Add to dashboard Cite

Cavity pressure in the injection molding process is closely related to the quality of the molded products and is used for process monitoring and control to upgrade the quality of molded products. However, the sensor installed inside the cavity makes the molded product of the cavity defective, reducing productivity. In view of this, this study investigates the correlation between melt pressure and cavity pressure in different runner positions and determines the appropriate runner position, where the runner pressure can represent the cavity pressure, in order to increase productivity. First, the Taguchi method is used to obtain the optimal parameter combination of injection molding, and then, the experiment is conducted based on this condition in order to discuss the difference between runner and cavity pressure history profiles. According to the experimental results, the quality of molded products can be monitored and controlled by installing sensors at different runner positions, and the maximum value of the cavity pressure profile varies with the runner position. When the distance between the top of the pressure sensor mounted in the secondary runner and the outside diameter of the runner is greater than the maximum thickness of the molded product, the obtained pressure history profile approximates to that inside the cavity. In other words, the runner pressure can represent the cavity pressure. Mold temperature significantly influences the runner pressure history profile and form accuracy (contour precision) of the lens during the injection molding process, which can be used as a process monitoring and control parameter. In addition, the cavity pressure profile at the cooling stage is closely related to the form accuracy of the lens and is the key to determining process monitoring and control parameter.

show abstract

Analysis of thermal contact resistance between polymer and mold in injection molding

Cited by 97 publications

References 8 publications

Sealing of polymer micro-structures by over-moulding

Sealing of polymer micro-structures by over-moulding

Hydrogen silsesquioxane mold coatings for improved replication of nanopatterns by injection molding

Correlation between runner pressure and cavity pressure within injection mold

Contact Info

Product

Resources

About