Evaluation of thermal contact resistance of molten resin–mold interface during high-thermal-conductivity polyphenylene sulfide filling in injection molding
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Akifumi Kurita
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Yohei Yoshimura
Abstract
High-thermal-conductivity polyphenylene sulfide (PPS) has both mechanical and heat dissipation properties, and its low weight and fuel efficiency make it a suitable replacement for metals in automobiles. However, this resin often causes filling defects in the injection molding process. This is due to the higher thermal conductivity, which causes the molten resin to solidify more quickly during the filling process. Therefore, it is important to predict the cooling and filling behaviors of the resin accurately using computer-aided engineering (CAE). Currently, many commercial software programs use thermal contact resistance (TCR) as the thermal boundary condition between the mold and resin. However, there is no established method to accurately evaluate TCR during filling with high spatial resolution and response, and the accuracy of CAE cannot be maintained. Therefore, we used thermography and a prismatic glass insert mold to thermally visualize and analyze the filling process of this resin. Consequently, we succeeded in evaluating TCR values with high spatial resolution and response. The obtained TCR values varied depending on the flow state and pressure. To further validate the obtained TCR values, we compared “the visualization results of real flow conditions” and “the flow prediction results of CAE considering the obtained TCR values”.
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Research ethics: Not applicable.
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Informed consent: Not applicable.
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Author contributions: The authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Competing interests: The authors state no conflict of interest.
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Research funding: None declared.
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Data availability: The raw data can be obtained on request from the corresponding author.
Appendix A: Physical properties of resins used in CAE
This section describes the physical properties of the high-thermal-conductivity PPS (E5101) used for the CAE. The melt viscosities are shown in Figure A.1. These values are obtained using a capillary rheometer (Toyo Seiki Co., Ltd.). The temperatures were 300 °C, 320 °C, and 340 °C. The barrel diameter was 9.55 mm, the die diameter was 1.0 mm, and the three die lengths were 10 mm, 20 mm, and 40 mm. The true viscosity was calculated by applying the Bagley + Rabinowisch correction to the apparent viscosity measured under the above conditions. The PVT characteristics are shown in Figure A.2, which were obtained based on publicly available information from Celanese Corporation. The specific heat values are shown in Figure A.3. The specific heat was measured by the method described in ASTM E1269 using differential scanning calorimetry at decreasing temperatures. Because the specific heat depends on the cooling rate, measurements are taken at two levels: 10 °C/min and 50 °C/min. The specific heat has a maximum value owing to crystallization, and the molten resin is considered to lose flowability at this temperature; therefore, this temperature is defined as the no-flow temperature in the CAE. As shown in Figure A.3, the specific heat peak shifts to the higher-temperature side as the cooling rate decreases. The objective of this study was to evaluate the safety of the unfilled molds during mold filling. Therefore, we adopted 247 °C as the no-flow temperature, where the specific heat peak is obtained at a sufficiently slow cooling rate of 10 °C/min. The thermal conductivities are presented in Figure A.4. The 3D TIMON software used in this study (Toray Engineering D Solutions, Inc.) considers only heat conduction in the thickness direction. Therefore, the thermal conductivity must be evaluated along the wall-thickness direction. The thermal conductivity at 23 °C is obtained based on information published by Celanese Corporation. We newly evaluated the thermal conductivity in the molten state at 300 °C by the flash method as additional information. The measurement device used was an LFA447 manufactured by NETZSCH. In the CAE, we used a linear approximation based on the thermal conductivities at the two values.
Melt viscosity of high-thermal-conductivity PPS (E5101).
PVT diagram of high-thermal-conductivity PPS (E5101).
Specific heat of high-thermal-conductivity PPS (E5101).
Thermal conductivity of high-thermal-conductivity PPS (E5101).
Nomenclature
- Q in
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Heat input [W]
- Q heat
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Amount of heat contributing to temperature rise [W]
- Q out
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Heat output [W]
- T 1
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Temperature of resin surface [°C]
- T 2
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Temperature of the mold surface [°C]
- T 3
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Temperature inside the mold [°C]
- R
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Thermal contact resistance at the resin–mold interface [m2·K/W]
- δR
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Error in R [m2·K/W]
- Δx
-
Width of mold surface microelements [m]
- Δy
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Thickness of mold surface microelements [m]
- Δz
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Depth of mold surface microelements [m]
- C v
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Specific heat by volume of the mold [J/(K·m3)]
- a
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Measurement interval distance between T2 and T3 [m]
- λ
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Thermal conductivity of the mold [W/(m·K)]
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© 2023 Walter de Gruyter GmbH, Berlin/Boston
Articles in the same Issue
- Frontmatter
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- Investigation of the effects of water uptake on the mechanical properties of wood dust particle filled Prosopis Juliflora reinforced phenol formaldehyde hybrid polymer composites
- Experimental investigation on mechanical and tribological analysis of pineapple leaf (Ananas comosus) and sisal (Agave sisalana) fibers reinforced hybrid epoxy composites
- An experimental study of weave pattern effect on the mechanical and dynamic behavior of composite laminates
- Structuring step dependent characteristics in joining using pin-like structures in the vibration welding process
- Fabrication of expandable graphite and soybean oil-based synergistic modified polyurethane foam with improved thermal stability and flame retardant properties
- Fabrication of electrospun nanofiber from a blend of PVC and PHB
- Investigation of mechanical and tribological performance of wood dust reinforced epoxy composite under dry, wet and heated contact condition
- Multi-layer co-extrusion blow molding
- Predicting part quality early during an injection molding cycle
- Optimizing laser-based micro-cutting for PMMA microfluidic device fabrication: thermal analysis and parameter optimization
- Preparation of PVDF/PVA composite films with micropatterned structures on light-cured 3D printed molds for hydrophilic modification of PVDF
- Evaluation of thermal contact resistance of molten resin–mold interface during high-thermal-conductivity polyphenylene sulfide filling in injection molding
- Effect of sinusoidal pulsating speed enhancement on the mixing performance of plastics machinery
- Experimental investigation on the mechanical and wear behavior of epoxy/Indian almond/peepal hybrid composites
- Exploration of the thermal and mechanical characteristics of polymethyl methacrylate-based copolymers: implications for wind turbine blades applications
Articles in the same Issue
- Frontmatter
- Research Articles
- Investigation of the effects of water uptake on the mechanical properties of wood dust particle filled Prosopis Juliflora reinforced phenol formaldehyde hybrid polymer composites
- Experimental investigation on mechanical and tribological analysis of pineapple leaf (Ananas comosus) and sisal (Agave sisalana) fibers reinforced hybrid epoxy composites
- An experimental study of weave pattern effect on the mechanical and dynamic behavior of composite laminates
- Structuring step dependent characteristics in joining using pin-like structures in the vibration welding process
- Fabrication of expandable graphite and soybean oil-based synergistic modified polyurethane foam with improved thermal stability and flame retardant properties
- Fabrication of electrospun nanofiber from a blend of PVC and PHB
- Investigation of mechanical and tribological performance of wood dust reinforced epoxy composite under dry, wet and heated contact condition
- Multi-layer co-extrusion blow molding
- Predicting part quality early during an injection molding cycle
- Optimizing laser-based micro-cutting for PMMA microfluidic device fabrication: thermal analysis and parameter optimization
- Preparation of PVDF/PVA composite films with micropatterned structures on light-cured 3D printed molds for hydrophilic modification of PVDF
- Evaluation of thermal contact resistance of molten resin–mold interface during high-thermal-conductivity polyphenylene sulfide filling in injection molding
- Effect of sinusoidal pulsating speed enhancement on the mixing performance of plastics machinery
- Experimental investigation on the mechanical and wear behavior of epoxy/Indian almond/peepal hybrid composites
- Exploration of the thermal and mechanical characteristics of polymethyl methacrylate-based copolymers: implications for wind turbine blades applications
