This study describes the influence of polymer flow length on mechanical properties of tested polymer, specifically polycarbonate. The flow length was examined in a spiral shaped mould. The mould cavity's surface was machined by several methods, which led to differing roughness of the surface. The cavity was finished by milling, grinding and polishing. In order to thoroughly understand the influence of the mould surface quality on the flow length, varying processing parameters, specifically the pressure, were used. The polymer part was divided into several segments, in which the micro-mechanical properties, such as hardness and indentation modulus were measured. The results of this study provide interesting data concerning the flow length, which was up to 3% longer for rougher surfaces, but shorter in cavities with polished surface. These results are in disagreement with the commonly practiced theory, which states that better surface quality leads to greater flow length. Furthermore, evaluation of the micro-mechanical properties measured along the flow path demonstrated significant variance in researched properties, which increased by 35% (indentation hardness) and 86% by indentation modulus) in latter segments of the spiral in comparison with the gate.

Faculty of Technology Tomas Bata University in Zlin Vavreckova 275 760 01 Zlín Czech Republic

Zobrazit více v PubMed

Shaw M.T., Jamieson A.M. Introduction to Polymer Rheology: From Suspenzions to Nanocomposites and Beyond. Wiley; Hoboken, NJ, USA: 2012.

Otsuka M., Oyabe A., Ito H. Effects of Mold Surface Conditions on Flow Length in Injection Molding Process. Polym. Eng. Sci. 2011;51:1383–1388. doi: 10.1002/pen.21931. DOI

Eladl A., Mostafa R., Islam A., Loaldi D., Soltan H., Hansen H.N., Tosello G. Effect of Process Parameters on Flow Length and Flash Formation in Injection Moulding of High Aspect Ratio Polymeric Micro Features. Micromachines. 2018;9:58. doi: 10.3390/mi9020058. PubMed DOI PMC

Salimi A., Subaşı M., Buldu L., Karataş Ç. Prediction of flow length in injection molding for engineering plastics by fuzzy logic under different processing conditions. Iran. Polym. J. 2013;22:33–41. doi: 10.1007/s13726-012-0103-5. DOI

Ershov S.V., Trufanova N.M. Numerical studies of the polymer melt flow in the extruder screw channel and the forming tool. Mater. Sci. Eng. 2017;208:012018. doi: 10.1088/1757-899X/208/1/012018. DOI

Pachner S., Loew-Baselli B., Affenzeller M., Miethlinger J. A generalized 2D output model of polymer melt flow in single-screw extrusion. Int. Polym. Process. 2017;32:209–216. doi: 10.3139/217.3326. DOI

Assoudi R., Lamzoud K., Chaoui M. Influence of the wall roughness on a linear shear flow. FME Trans. 2018;46:272–277. doi: 10.5937/fmet1802272A. DOI

Ebrahimi M., Konaganti V.K., Moradi S., Hatzikiriakos S.G. Annual Technical Conference—ANTEC, Conference Proceedings. Society of Plastics Engineers; Brookfield, CT, USA: 2017. Surface roughness and energy on slip of polymer melts.

Zink B., Szabó F., Hatos I., Suplicz A., Kovács N.K., Hargitai H., Tábi T., Kovács J.G. Enhanced Injection Molding Simulation of Advanced Injection Molds. Polymers. 2017;9:77. doi: 10.3390/polym9020077. PubMed DOI PMC

Hua S., Zhang S., Cao W., Wang Y., Shao C., Liu C., Dong B., Shen C. Simulation of jetting in injection molding using a finite volume method. Polymers. 2016;8:172. doi: 10.3390/polym8050172. PubMed DOI PMC

Gao S., Qiu Z., Ouyang J., Yang Y. Wall slip of linear polymer melts during ultrasonic-assisted micro-injection molding. Polym. Eng. Sci. 2019;59:7–13. doi: 10.1002/pen.24953. DOI

Stanek M., Manas M., Ovsik M., Reznicek M., Senkerik V., Janostik V. Polymer flow influenced by mold cavity surface roughness. Manuf. Technol. 2019;19:327–331. doi: 10.21062/ujep/291.2019/a/1213-2489/MT/19/2/327. DOI

Stanek M. Influence of Tool, Material and Process on the Quality of Injection Molded Products. TBU in Zlin; Zlín, Czech Republic: 2021.

Bellantone V., Surace R., Trotta G., Fassi I. Replication capability of micro injection moulding process for polymeric parts manufacturing. Int. J. Adv. Manuf. Technol. 2013;67:1407–1421. doi: 10.1007/s00170-012-4577-2. DOI

Fluxa P., Stanek M., Ovsik M., Dockal A. Polyoxymethylene flow enhancement using the rough surface injection mould cavity. MM Sci. J. 2020:3878–3881. doi: 10.17973/MMSJ.2020_06_2019018. DOI

Halevi G. Process and Operation Planning Boston. Kluwer Academic Publishers; Norwell, MA, USA: 2013.

Mani M.R., Surace R., Ferreira P., Segal J., Fassi I., Ratchev S. Process Parameter Effects on Dimensional Accuracy of Microinjection Moulded Part. J. Micro Nano-Manuf. 2013;1:1–8. doi: 10.1115/1.4025073. DOI

Manas D., Mizera A., Navratil J., Manas M., Ovsik M., Sehnalek S., Stoklasek P. The electrical, mechanical and surface properties of thermoplastic polyester elastomer modified by electron beta radiation. Polymers. 2018;10:1057. doi: 10.3390/polym10101057. PubMed DOI PMC

Manas D., Mizera A., Manas M., Ovsik M., Hylova L., Sehnalek S., Stoklasek P. Mechanical properties changes of irradiated thermoplastic elastomer. Polymers. 2018;10:87. doi: 10.3390/polym10010087. PubMed DOI PMC

Ovsik M., Manas M., Stanek M., Dockal A., Vanek J., Mizera A., Adamek M., Stoklasek P. Polyamide surface layer nano-indentation and thermal properties modified by irradiation. Materials. 2020;13:2915. doi: 10.3390/ma13132915. PubMed DOI PMC

Oliver W.C., Pharr G.M. Measurement of hardness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodology. J. Mater. Res. 2004;19:3–20. doi: 10.1557/jmr.2004.19.1.3. DOI