This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Advances in Thermoset Injection Molding Part IV: Knitline and Elevated Temperature Properties in Thermoset Composites
Annotation ability available
Sector:
Language:
English
Abstract
The injection molding of thermoset composites gives certain advantages over compression molding techniques such as higher productivity rates, better part quality, and better adaptability to automation. The disadvantages of the injection molding process for thermoset composites include lower mechanical properties and fiber orientation effects. Recent developments in process and materials have significantly improved the mechanical properties and surface smoothness of injection molded thermoset composites. Even with these material improvements several molding problems occur in the injection molding production process. Two important production problems are cracks and porosity at the knitline areas and cracks during the handling of the hot part immediately after molding and other elevated temperature processes. This paper will illustrate the development of a unique mold configuration to simulate knitlines in a ribbed rectangular injection mold. By studying mechanical properties in these knitline areas, a method to evaluate process and material variables has been developed. By measuring mechanical properties at elevated temperatures, the strength of the composite during high temperature processes can be simulated. This provides another method to evaluate material variables and their effect in a simulated production situation.
Authors
Citation
Atkins, K., Seats, R., Montagne, M., and Behar, G., "Advances in Thermoset Injection Molding Part IV: Knitline and Elevated Temperature Properties in Thermoset Composites," SAE Technical Paper 930172, 1993, https://doi.org/10.4271/930172.Also In
References
- Wood, Gene 1988 “Analysis on New automated Manufacturing Cells: Methods and Processing that Can Produce Parts in 50 Seconds for S.M.C., the New Z.M.C. Process for Injection Molding of Polyesters, and the Reinforced Thermoplastic Industry.” 43rd Annual SPI-RP Conference
- Montagne, M.H.P. Atkins K.E. Rex G.C. Veit R. 1989 “Low Profile Injection Molding Materials.” 44th Annual SPI-RP Conference
- Atkins, K.E. Seats R.L. Rex G.C. 1991 “Advances in Thermoset Injection Molding.” 46th Annual SPI-RP Conference
- Demiez, Karin 1991 “Injection Molding of BMC Automotive Parts: Higher Performance through a Total System Approach.” 46th Annual SPI-RP Conference
- Atkins, K.E. et al. 1992 “Advanced Injection Molding-Part III: High Strength/Class A Rigid and Flexible Composites.” 47th Annual SPI-RP Conference
- Sanschagrin, B. et. al. 1987 “Weldlines in Injection Molded Polypropylene: Effect of Filler Shape.” 42nd Annual SPI-RP Conference
- Fisa, B. et. al. 1991 “Weldlines in Fiber Reinforced Materials: A Review.” 46th Annual SPI-RP Conference
- Gibson, A.G. et. al. 1988 “A Rheological Model for the Behavior of Reinforced Polymer Melts in Convergent Flow.” 43rd Annual SPI-RP Conference
- Narkis, M. et. al. 1989 “Quantitative Measurement of Fiber Orientation and Fracture, Void and Weld-Lines in Short Fiber Reinforced Thermoplastic Composites.” 44th Annual SPI-RP Conference
- Barker, R.H. 1989 “Elevated Temperature Performance under Stress Load.” 44th Annual SPI-RP Conference
- Herzog, D.J. et. al. 1991 “Expansion of High Temperature Applications for SMC Composites with the Development of a New High Crosslink SMC Vinyl Ester Resin.” 46th Annual SPI-RP Conference