Effect of chemical blowing agent, melt temperature, and mold temperature on the fluidity of glass fiber-reinforced polycarbonate in injection molding

ABSTRACT

Glass fiber (GF) reinforced polycarbonate (PC) is a composite material that is used in the production of mobile phones, automobiles, LCD monitors, and laptops. With an increase in the GF content, the fluidity of the composite material decreases owing to the flow resistance of GF. A decrease in the fluidity leads to a decrease in processability and moldability; thus, applications of GF reinforced polymers are limited. Here, we investigated whether the fluidity of GF reinforced PC can be increased by using a chemical blowing agent (CBA) and by controlling the melt temperature and mold temperature. In this study, PC was reinforced with GF (45 wt%) using a CBA. Samples of GF reinforced PC were injection molded with respect to varying variables such as CBA content, melt temperature, and mold temperature. We used a spiral mold to compare the fluidity and measured the spiral flow length of the samples. The results indicated that increase in the CBA content increased the fluidity of GF reinforced PC. Furthermore, the results confirmed that the addition of CBA exhibits a considerably higher effect on fluidity than an increase in the melt temperature or mold temperature. Our findings are expected to significantly impact the expanding applications of GF reinforced plastics in the future.

Graphical abstract

KEYWORDS:

• Chemical blowing agent (CBA)
• fluidity
• melt viscosity
• melt flow index
• polycarbonate
• glass fiber-reinforced polymer
• injection molding

Conflicts of Interest

The authors declare no conflict of interest.

Additional information

Notes on contributors

Kihyoung Kim

Kihyoung Kim graduated from Yonsei University with a master's degree in mechanical engineering. His field of research includes injection molding and reinforced plastics.

Youngjae Ryu

Youngjae Ryu is a Ph.D. candidate in the department of mechanical engineering at Yonsei University. His research focuses on microcellular foaming and manufacturing process.

Joo Seong Sohn

Joo Seong Sohn is a Ph.D. candidate in the department of mechanical engineering at Yonsei University. His research interests are microcellular foaming and bioplastics.

Sung Woon Cha

Sung Woon Cha is currently a professor of the mechanical engineering at Yonsei University. He graduated from MIT with a Ph.D. in Mechanical Engineering. His major research interests are microcellular foaming and axiomatic design.