*Influence of Injection Molding Parameters on the Mechanical Properties of Injected PC/ABS Parts DOI: http://dx.doi.org/10.5772/intechopen.95089*

number of experiments required could be reduced to nine, instead of 81 (34 ) experiments to find out the parameters that influence on the mechanical properties.

As depicted in **Table 3**, an orthogonal array (OA) L**9** was involved to investigate the effect of the process IM parameters. Three levels for each factor were studied. The DOF for the three levels was 2 (DOF = number of levels−1).

The elaboration of the injected PC/ABS parts was done within the SKG factory. Each combination was iterated 5 times (9 × 5 = 45). The tensile strength and the elasticity module of the injected PC/ABS parts were regarded as the desired responses.


**Table 3.**

*Quality Control - Intelligent Manufacturing, Robust Design and Charts*

the factors and their levels was made as illustrated in **Table 2**.

strength and the elasticity module.

*Geometric and process factors in three levels.*

**2.5 Tensile tests**

**Table 2.**

in **Figure 2**.

Following preliminary tests carried out within the SKG Company, the choice of

The impact of the injection molding parameters on the mechanical characteristics are evaluated through the S/N ratio obtained in the Taguchi experimental plan. The S/N ratio was calculated by the larger is better quality characteristic for determining the effect of each process IM factor. The responses required are the tensile

**Index Factors Unit Level 1 Level 2 Level 3** A Material Temperature °C 240 250 260 B Injection Pressure bar 30 40 50 C Holding Time sec 4 8 14 D Temperature Mold °C 40 50 60

The tensile tests were carried out, with imposed displacement, on a machine of

All tests were achieved at ambient temperature and for a strain rate of 5 mm/ min. The local deformation of the specimens during these tests was measured using an extensometer having an initial length of 25 mm and an elongation of ±1 mm. The measurement was repeated at least 4 times for the samples and the average of three sample readings was taken for accurate results. The specimens used for the simple tensile test are taken from the ISO 527-2 standard. Its geometry is illustrated

The injection molding (IM) process parameters considered in this study were:

In order to optimize these parameters, the famous optimization approach Taguchi was adopted. One main reason for using Taguchi is the low number of experiments. The

material temperature (A), injection pressure (B), holding time (C) and mold

the LLYOD INSTRUMENT type equipped with a 5 kN load cell.

**154**

**2.6 Experimental**

*Tensile specimen geometry (in mm).*

**Figure 2.**

temperature (D).

*Experimental layout using an L9 orthogonal array.*
