Effect of Processing Techniques on the Microstructure and Mechanical Performance of High-Density Polyethylene

Abstract

The versatility of high-density polyethylene (HDPE) makes it one of the most used polymers for vast applications ranging from food packaging to human implants. However, there still is confusion regarding the proper selection of processing techniques to produce HDPE specimens for high-end applications. Herein, we compare the processing of HDPE by two relevant techniques: compression and injection molding. The fabricated samples were studied using uniaxial tensile testing to determine their mechanical performance. Furthermore, the microstructure of samples was analyzed using different characterization techniques. Compression-molded specimens recorded a higher degree of crystallinity (DC) using two different characterization techniques such as differential scanning calorimetry (DSC) and X-ray diffraction (XRD). With this information, critical processing factors were determined, and a general structure–property relationship was established. It was demonstrated that having a higher DC resulted in higher yield strength and Young’s modulus. Furthermore, premature failure was observed in the injection-molded specimens, resulting in lower mechanical performance. This premature failure was caused due to flow marks observed using scanning electron microscopy (SEM). Therefore, it is concluded that compression molding produces superior samples compared to injection molding.

Impact of Hybrid Fillers on the Properties of High Density Polyethylene Based Composites

“…The percent elongation has been measured to be in the r 645% and their values reduce with filler contents. Similar results and behavi reported in [8,[29][30][31][32][33]; this behavior for the composite materials is a result of t stiffness of the composites that was attributed to interaction between the hybrid fillers and the fillers have fewer elongation values; this reduction in el reduced the ductility, and limited the stretching of the composites. In anoth fillers loading have restrained the HDPE polymer chains movement and res presence of highly localized strain, which cause de-wetting between the HDP fillers.…”

“…In addition, in the work of Mourad and his research group [29][30][31][32] and in reference [33] a melting temperature of HDPE and its composites in the range 127.8-132 • C has been obtained; this range is coincident to the temperature range in Figure 1. materials; moreover, other formulations exhibited a similar behavior comp the unfilled HDPE; this indicate that the higher amount of both talc and filler in the presence of highest amount of FS can affect the melting te polymer composites not significantly; these results indicate that filler type a can affect the melting temperature of the final composites materials very s addition, in the work of Mourad and his research group [29][30][31][32] and in re melting temperature of HDPE and its composites in the range 127.8-132 obtained; this range is coincident to the temperature range in Figure 1.…”

“…Formulations 2 (75% HDPE + 25% talc), 6 (75% HDPE + 25% CaCO 3 ), 13 (70% HDPE + 12.5% talc + 12.5% CaCO 3 + 5% FS) and 16 (72% HDPE + 20% talc + 5% CaCO3 + 3% FS) showed high T m , approximately 0.96% (1.29 • C) and 1.08% (1.44 • C) increase, respectively, compared to that of the unfilled HDPE; this implies that 12.5% talc and 12.5% CaCO 3 in the presence of FS at the highest loading level (5%) enhances the stability of the pure HDPE matrix and subsequently improve the melting temperature of the composites materials; moreover, other formulations exhibited a similar behavior compared to that of the unfilled HDPE; this indicate that the higher amount of both talc and CaCO 3 hybrid filler in the presence of highest amount of FS can affect the melting temperature of polymer composites not significantly; these results indicate that filler type and its loading can affect the melting temperature of the final composites materials very slightly [28]. In addition, in the work of Mourad and his research group [29][30][31][32] and in reference [33] a melting temperature of HDPE and its composites in the range 127.8-132 • C has been obtained; this range is coincident to the temperature range in Figure 1. materials; moreover, other formulations exhibited a similar behavior comp the unfilled HDPE; this indicate that the higher amount of both talc and filler in the presence of highest amount of FS can affect the melting te polymer composites not significantly; these results indicate that filler type a can affect the melting temperature of the final composites materials very s addition, in the work of Mourad and his research group [29][30][31][32] and in re melting temperature of HDPE and its composites in the range 127.8-132 obtained; this range is coincident to the temperature range in Figure 1.…”

Effect of Au Plasmonic Material on Poly M-Toluidine for Photoelectrochemical Hydrogen Generation from Sewage Water

“…A potentiodynamic technique in the three-electrode cell was performed in the electropolymerization phase of MT to form PMT, as defined in our previous study [32]. The electropolymerization reaction was carried out on ITO glass (20 Ω) through the anodic polymerization reaction using Potentiostat/Galvanostat Wenking (PGS 95), Hubertusstr, Germany.…”

Investigation of the Warpage of a High-Density Polyethylene Pallet by Plastic Injection Compression Molding: Part I—Numerical Approach

“…By differential scanning calorimetry (DSC) and X-ray diffraction (XRD), a tensile specimen of HDPE formed by ICM was found to have a higher yield strength and Young’s modulus than the one formed by injection molding. These mechanical properties of the specimen are proportional to its crystallization percentage [ 6 ]. The tensile properties were significantly reduced with an increasing temperature, while the elastic modulus and the ultimate tensile strength linearly increased at higher strain rates.…”