Evaluation of heat transfer coefficient between polymer and cavity wall for improving cooling and crystallinity results in injection molding simulation

Liu, Yao; Gehde, Michael

doi:10.1016/j.applthermaleng.2015.01.064

Cited by 39 publications

(20 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because of volumetric shrinkage, an air gap is formed between the cavity wall and the injection-molded part, so heat transfer between the injected part and the mold drops significantly. The melt flow and temperature distribution can be calculated with Navier-Stokes' momentum (1), continuity (2), and energy (3) conservation equations [10,18]:…”

Section: Heat Transfer Equationsmentioning

confidence: 99%

“…The melt flow and temperature distribution can be calculated with Navier-Stokes' momentum (1), continuity (2), and energy (3) conservation equations [10,18]:…”

Section: Heat Transfer Equationsmentioning

confidence: 99%

“…The analytical solution of the part temperature was introduced into the BEM, so the random access memory (RAM) size required for the calculations was reduced by 93% on average and calculation time was shortened by one order of magnitude. Liu and Gehde [10] analyzed the influence of the heat transfer coefficient (HTC) between the polymer and cavity wall on cooling and crystallinity. They found that melt temperature and surface roughness have important roles on the determination of the HTC.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Enhanced Injection Molding Simulation of Advanced Injection Molds

et al. 2017

View full text Add to dashboard Cite

Abstract:The most time-consuming phase of the injection molding cycle is cooling. Cooling efficiency can be enhanced with the application of conformal cooling systems or high thermal conductivity copper molds. The conformal cooling channels are placed along the geometry of the injection-molded product, and thus they can extract more heat and heat removal is more uniform than in the case of conventional cooling systems. In the case of copper mold inserts, cooling channels are made by drilling and heat removal is facilitated by the high thermal conductivity coefficient of copper, which is several times that of steel. Designing optimal cooling systems is a complex process; a proper design requires injection molding simulations, but the accuracy of calculations depends on how precise the input parameters and boundary conditions are. In this study, three cooling circuit designs and three mold materials (Ampcoloy 940, 1.2311 (P20) steel, and MS1 steel) were used and compared using numerical methods. The effect of different mold designs and materials on cooling efficiency were examined using calculated and measured results. The simulation model was adjusted to the measurement results by considering the joint gap between the mold inserts.

show abstract

Section: Heat Transfer Equationsmentioning

confidence: 99%

“…The melt flow and temperature distribution can be calculated with Navier-Stokes' momentum (1), continuity (2), and energy (3) conservation equations [10,18]:…”

Section: Heat Transfer Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Enhanced Injection Molding Simulation of Advanced Injection Molds

et al. 2017

View full text Add to dashboard Cite

show abstract

“…They noted, that the conductance decreases when the roughness increases. Liu et al [25] showed through injection molding simulations that the melt temperature and the cavity surface roughness has important role on the conductance.…”

Section: Introductionmentioning

confidence: 99%

Thermal simulations and measurements for rapid tool inserts in injection molding applications

Kovács

Szabó

Kovács

et al. 2015

Applied Thermal Engineering

View full text Add to dashboard Cite

Rapid prototyping (RP) is a widely used process in the industry to shorten development time.Another advantage of this technology is the ability to create conformal cooling systems, thus not only cooling time and cycle time can be shortened, but also shrinkage, thus warpage can be decreased. The main disadvantage of Rapid prototyping materials is their low thermal conductivity, which strongly influences cooling properties and warpage.The research based on a special developed injection mold for novel rapid prototyping based mold inserts with cooling systems. A method has been introduced to determine the most important thermal parameters for injection molding simulations using rapid tools. Those parameters, which can be measured such as the specific heat and thermal conductivity of the mold materials, are directly implemented into the software. The heat transfer coefficient between the polymer melt and the rapid tool insert surface cannot be measured in a reasonable way, thus simulation software was used to determine that based on indirect calculation 2 derived from real measurements. In the paper, the method was proved with Fused Deposition Modeling (FDM) and Polyjet mold inserts.

show abstract

“…Another analogical aspect can be found in the injection molding of polymers. According to Liu and Gehde (2015), heat transfer is one of the most important segments in injection molding because it significantly affects the temperature distribution of the component and alters the temperature distribution in the mold, thereby affecting the mechanical behavior and dimensional precision of the plastic component, as well as production efficiency. In our case, the question is not of the first molding stage, but the same phenomena are present during the post-processing stage, in which the WPC plate is at an elevated temperature and is pressed into its final geometry.…”

Section: Introductionmentioning

confidence: 99%

Manufacturability of Wood Plastic Composite Sheets on the Basis of the Post-Processing Cooling Curve

Matthews¹,

Toghyani²,

Eskelinen³

et al. 2015

BioResources

View full text Add to dashboard Cite

Extruded wood-plastic composites (WPCs) are increasingly regarded as promising materials for future manufacturing industries. It is necessary to select and tune the post-processing methods to be able to utilize these materials fully. In this development, temperature-related material properties and the cooling rate are important indicators. This paper presents the results of natural cooling in a factory environment fit into a cooling curve function with temperature zones for forming, cutting, and packaging overlaid using a WPC material. This information is then used in the evaluation of manufacturability and productivity in terms of cost effectiveness and technical quality by comparing the curve to actual production time data derived from a prototype post-process forming line. Based on this information, speed limits for extrusion are presented. This paper also briefly analyzes techniques for controlling material cooling to counter the heat loss before post-processing.

show abstract

Evaluation of heat transfer coefficient between polymer and cavity wall for improving cooling and crystallinity results in injection molding simulation

Cited by 39 publications

References 20 publications

Enhanced Injection Molding Simulation of Advanced Injection Molds

Enhanced Injection Molding Simulation of Advanced Injection Molds

Thermal simulations and measurements for rapid tool inserts in injection molding applications

Manufacturability of Wood Plastic Composite Sheets on the Basis of the Post-Processing Cooling Curve

Contact Info

Product

Resources

About