对热流道系统注塑工艺英文文献和中文翻译(8)
A. Demirer et al. / Materials and Design 28 (2007) 1467–1476 1475
Density variation for ABS
1.16
1.15
1.14
1.13
1.12
1.11
1.1
50 40 40 70 60 50
Injection Pressure (MPa)
Fig. 11. Density variation of the injected parts vs. process temperature and injection pressure for ABS polymer when using both HRS and CRS.
Fig. 12. Density variation of the injected parts vs. process temperature and injection pressure for PP polymer when using both HRS and CRS.
Table 5
Density variation of the injected parts vs. process temperature and injection pressure for base polymers when using both HRS and CRS
Base polymer Process temperature (°C) HRS CRS
Injection pressure (MPa) Density (g/cm3) Injection pressure (MPa) Density (g/cm3)
ABS 245 50 1.159 70 1.136
260 40 1.158 60 1.131
280 40 1.157 50 1.117
PP 170 80 0.9652 80 0.9337
120 0.9683 120 0.9636
200 40 0.9605 70 0.9290
100 0.9655 100 0.9258
260 30 0.9370 45 0.9330
tance between the outermost edge of the part and the gate is smaller due to the nozzle location, and the pressure and heat losses are also lower due to the eliminating sprue. Thus, the packing pressure and the melt temperature,
which are the most influential process parameters on the void generation as mentioned above, can be controlled more easily and accurately, so higher sample weights are achievable [10].
1476 A. Demirer et al. / Materials and Design 28 (2007) 1467–1476
The weights of the parts produced in the experiments were measured after 30 days. Figs. 11 and 12 show the vari- ations in densities of the injected parts vs. injection pressure for the experimented temperatures. According to these fig- ures, the density of the injected parts is higher at low tem- peratures than that of high temperatures. The increasing effect of injection pressure on density is also noticeable from the figures. It was observed that the densities of the samples increased with the increasing injection pressure. Determined sample densities vs. process temperature and injection pressure are presented in Table 5.