Effects of nano-fillers and process conditions on the microstructure and mechanical properties of microcellular injection molded polyamide nanocomposites

2003 ◽  
Vol 24 (6) ◽  
pp. 655-671 ◽  
Author(s):  
Hrishikesh Kharbas ◽  
Paul Nelson ◽  
Mingjun Yuan ◽  
Shaoqin Gong ◽  
Lih-Sheng Turng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Process Conditions ◽  
Microstructure And Mechanical Properties ◽  
Injection Molded

Micro-Injection Molding of Polymer Nanocomposites Composition-Process-Properties Relationship

2021 ◽  
Vol 36 (3) ◽  
pp. 276-286
Author(s):  
Z. Dekel ◽  
S. Kenig
Keyword(s):  
Mechanical Properties ◽  
Plug Flow ◽  
Volume Resistivity ◽  
Process Conditions ◽  
Polyamide 66 ◽  
Fountain Flow ◽  
Microinjection Molding ◽  
Injection Molded ◽  
Composition Process ◽  
Rheological Percolation

Abstract The mechanical, electrical, thermal, and rheological properties of micro injection molded nanocomposites comprising 2% and 5% carbon nanotubes (CNTs) incorporated in polycarbonate (PC), and polyamide 66 (PA) were studied. The design of experiments method was used to investigate the composition-process – properties relationship. Results indicated that the process variables significantly affected the flow patterns and resulting morphology during the filling stage of the microinjection molding (lIM) process, using 0.45 mm diameter lIM samples. Two distinct flow regimes have been identified in lIM using the low cross-section samples. The first was a conventional “fountain flow,” which resulted in a skin/core structure and reduced volume resistivity up to 10 X cm in the case of 5% CNTs and up to 100 X cm in 2% CNTs, in both polymers, respectively. In addition, inferior mechanical properties were obtained, attributed to polymer degradation under high shear rate conditions, when practicing high injection speeds, high mold temperatures, and high screw rotation velocities. The second was a “plug flow” due to wall slippage, obtained under low injection speeds, low mold temperatures, and low rotation velocities, leading to a substantial increase in modulus of elasticity (60%) with increased electrical resistivity up to 103 X cm for 5% CNTs and 105 X cm for 2% CNTs, respectively. The rheological percolation threshold was obtained at 2% CNTs while the electrical threshold was attained at 0.4% CNTs, in both polymers. It was concluded that in lIM, the process conditions should be closely monitored. In the case of high viscous heating, degradation of mechanical properties was obtained, while skin- core morphology formation enhanced electrical conductivity.

Effects of Process Conditions on the Mechanical Properties of Microcellular Injection Molded Polycarbonate Parts

2007 ◽  
Vol 27 (2) ◽  
pp. 153-165 ◽  
Author(s):  
Shia Chung Chen ◽  
Jui Pin Yang ◽  
Jeng Sheng Hwang ◽  
Ming Hsiu Chung
Keyword(s):  
Mechanical Properties ◽  
Process Conditions ◽  
Injection Molded

scholarly journals Effects of Injection-molded Conditions on the Microstructure and Mechanical Properties of PC/LCP Blends

2006 ◽  
Vol 63 (6) ◽  
pp. 360-367 ◽  
Author(s):  
Jianhui QIU ◽  
Noboru NAKAYAMA ◽  
Tetsuo KUMAZAWA ◽  
Guoyue CHEN ◽  
Makoto KUDO ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure And Mechanical Properties ◽  
Injection Molded

Correlation Between Mechanical Properties in Standard Test Specimens and Injection Molded Thin-Wall Parts

2013 ◽  
Author(s):  
Laurentiu I. Sandu ◽  
Felicia Stan ◽  
Catalin Fetecau
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Injection Molding ◽  
Process Conditions ◽  
Thin Wall ◽  
Optimal Process ◽  
Melt Temperature ◽  
Molded Parts ◽  
Injection Molded

In this paper, we investigated the effect of injection molding parameters on the mechanical properties of thin-wall injection molded parts. A four-factor (melt temperature, mold temperature, injection speed and packing pressure) and three-level fractional experimental design was performed to investigate the influence of each factor on the mechanical properties and determine the optimal process conditions that maximize the mechanical properties of the part using the signal-to-noise (S/N) ratio response. The mechanical properties (e.g., elastic modulus, yield strength and strain at break) were measured by tensile tests at room temperature, at a crosshead speed of 5 mm/min, and compared with those of the injection-molded specimens. The experimental results showed that the tensile properties were highly dependent on the injection molding parameters, regardless of the type of the specimens. The values of Young modulus and yield strength of the injection-molded specimens were lower than those of the injection-molded parts, while the elongation at break was considerably lower for the injection-molded parts. The optimal process conditions were strongly dependent on the measured performance quantities (elastic modulus, yield strength and strain at break).

Comprehensive study on the relationships between the processing, the microstructure, and mechanical properties of injection molded polypropylenes

2017 ◽  
Vol 58 (S1) ◽  
pp. E215-E225 ◽  
Author(s):  
Carlos N. Barbosa ◽  
Ricardo Simoes ◽  
Markus Franzen ◽  
Thomas Baranowski ◽  
Julio C. Viana
Keyword(s):  
Mechanical Properties ◽  
Microstructure And Mechanical Properties ◽  
Injection Molded ◽  
Comprehensive Study
Sign in / Sign up

Export Citation Format

Share Document