## 5 Experimental Design  
The experimental design is based on the research of [PERSON] et al. [10] on the flow behavior of the melt in an injection mold, which was conducted using various viscosity models. The focus of the experiments is the tracking of the flow front in the cavity. The experimental configuration involves a two-cavity mold for specimen production, with each cavity measuring 62.0 mm in length and width and a thickness of 2.1 mm. The experiments are conducted using an Engel EM 200/100 tie-bar-less all-electric injection molding machine, which has a 30 mm screw diameter and a maximum clamping force of 1000 kN. In accordance with the simulation, the material Schulamid 66 SK 1000 from LyondellBasell  
Figure 4: Double-logarithmic plot of viscosity versus shear rate for the fitted rheological models and the data points of the CAMPUS database at a temperature of 290 \({}^{\circ}\)C.  
Figure 5: Double-logarithmic plot of viscosity versus shear rate for the fitted rheological models and the data points of the CAMPUS database at a temperature of 300 \({}^{\circ}\)C.  
will be employed in the experiments. Table 4 presents a summary of the material properties of the employed polymer [58]. The injection molding experiments were employed to substantiate the results of the simulations. Initially, the parameters for the injection molding process were identified and established, as outlined in Table 5. Subsequently, a series of fills was conducted without holding pressure, starting with a metering volume set much lower than the required amount to fill the cavity and incrementally increasing it with each cycle. The parts ejected from the mold demonstrated the progression of the flow front [10]. This test involved two consecutive filling stages, allowing for detailed observation of the melt entering the cavity and progressing to full cavity filling. \begin{table}
\begin{tabular}{c c} \hline
**Property** & **Value (Dry/Condensed)** \\ \hline Tensile yield stress & 50/30 MPa \\ \hline Tensile elongation & 6/32\% \\ \hline Young’s modulus & 1800/600 MPa \\ \hline Charpy impact strength (23 \({}^{\circ}\)C) & 80/120 kJ/m\({}^{2}\) \\ \hline Vicat softening temperature (50 \({}^{\circ}\)C/h, 50 N) & 175 \({}^{\circ}\)C \\ \hline Melt temperature & 280–300 \({}^{\circ}\)C \\ \hline Mold temperature & 60–100 \({}^{\circ}\)C \\ \hline Moisture absorption & 2\% \\ \hline Predrying time & 4–6 h \\ \hline Predrying temperature & 80 \({}^{\circ}\)C \\ \hline \end{tabular}
\end{table} 
Table 4: Material properties Schulamid 66 SK 1000 used for experiments. \begin{table}
\begin{tabular}{c c} \hline
**Property** & **Value** \\ \hline Clamping force & 500 kN \\ \hline Mold temperature (inlet flow) & 80 \({}^{\circ}\)C \\ \hline Cylinder temperature zone 1 (nozzle) & 275 \({}^{\circ}\)C \\ \hline Cylinder temperature zone 2 & 280 \({}^{\circ}\)C \\ \hline Cylinder temperature zone 3 & 265 \({}^{\circ}\)C \\ \hline Cylinder temperature zone 4 & 255 \({}^{\circ}\)C \\ \hline Cylinder temperature zone 5 (feeding) & 40 \({}^{\circ}\)C \\ \hline Injection speed & 37.2 cm\({}^{3}\)/s \\ \hline Metering volume & variable \\ \hline Metering speed & 0.4 m/s \\ \hline Back Pressure & 50 bar \\ \hline Residual cooling time & 15 s \\ \hline Melt cushion & constant \\ \hline Changeover point holding pressure & constant \\ \hline Shut-off nozzle (yes/no) & yes \\ \hline \end{tabular}
\end{table} 
Table 5: Experimental set-up data for the injection molding machine Engel EM 200/100. The influence of filling pressure causes the melt column to undergo compression between the screw tip and the flow front. After reaching the changeover point and stopping injection, this column decompresses, affecting the filling level achieved. As the simulation does not account for compressibility, it is crucial to maintain the melt column size constant to ensure accurate comparison with experimental results. Therefore, the filling series was conducted by adjusting the metering volume rather than altering the changeover point.