Temperature and shear rate distributions of gas‐assisted injection molded (GAIM) polypropylene and the application in forecast of cooling time

Abstract

An umbrella handle product of polypropylene molded by gas‐assisted injection molding (GAIM) was studied from both aspects: theoretical modeling and simulation as well as in situ temperature measurement. The simulation was primarily through the use of the commercial software Moldflow (version 6.1) coupled with enthalpy transformation method (ETM) in an attempt to investigate the shear rate and temperature fields during GAIM process. A four‐parameter model (FPM) was used to nonlinearly fit the temperature decays during the GAIM cooling stage on the basis of a three‐parameter model (TPM) raised previously in our group. The FPM showed perfect fitting effect as well as presented fairly acceptable cooling time (tc) prediction in comparison to experimental data, which could better reflect the nature of crystalline polymers during melt crystallization process. The understanding of the shear rate and temperature fields would be of practical importance to the further research on relationship of “processing–structure–property” as well as the optimization of cooling parameters for industrial GAIM operations of crystalline polymers. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47390.

A Facile Way of Enhancing Thermal Conduction in Epoxy-Based Nanocomposites via Construction of Well-Defined Hybrid Filler Networks Using a Magnetic Field

“…eq ) have proved to be powerful for studying the cooling (phase change) process of crystalline polymers previously. The present work attempted to apply both TPM and FPM equations to learn the temperature rise process and compare the difference in the fitting effect between model predictions (via TPM/FPM) and experimental data (e.g., Q0, Q1, Q1′, Q4, and Q4′) with the results shown in Figure . , All fitting parameters were summarized in Tables S1 and S2 in the Supporting Information where y = θ, x = ln t , and in the three parameters A - C of TPM, parameter A is related to T 0 , parameter B is related to T w , and parameter C is closely correlated to composites’ properties (i.e., composition, filler content, and dispersion state). …”

“…The present work attempted to apply both TPM and FPM equations to learn the temperature rise process and compare the difference in the fitting effect between model predictions (via TPM/FPM) and experimental data (e.g., Q0, Q1, Q1′, Q4, and Q4′) with the results shown in Figure 4. 46,47 All fitting parameters were summarized in Tables S1 and S2 in the Supporting Information…”

Facile way of dynamically tailoring microporous structures in polyvinylidene fluoride films prepared by thermally induced phase separation

“…From the overall morphologies of the films (Figure 4(a 0 -d 0 )), the microstructure of the films exhibited complex hierarchical structure. In order to further interpret the relationship between microstructures in the films and temperature fields of the polymer solution, enthalpy transformation method (ETM) [49][50][51][52][53][54] was used here to acquire the three-dimensional temperature fields during the film formation process at different TIPS quenching temperatures (cf. Figure 5).…”

Experimental analysis of fluid‐assisted injection molding of pipe fittings with different angles by short‐shot method

“…Yang et al 22 explored the influence of preinjection volume, water pressure, and (A) overflow method (B) short-shot method F I G U R E 1 Fluid assisted injection molding process melt temperature on the melt hollow ratio by computational fluid dynamics method and response surface method. Yang et al 23 developed a polypropylene umbrella handle model by combining the software Moldflow with ETM, and investigated the effects of shear rate and temperature field on the quality of parts during gas-assisted injection molding. Wang et al 24 applied the mechanism of back pressure to study the influencing factors of the gas penetration length and hollow ratio of the short-shot method.…”