注塑模具的设计与热分析英文文献和翻译(6)
Table 2
Material properties for mould and product
Carbon Steel (AISI 1050), mould ABS Polymer, product
Density, ρ 7860 kg/m3 Density, ρ 1050 kg/m3
Young’s modulus, E 208 GPa Young’s modulus, E 2.519 GPa
Poisson’s ratio, ν 0.297 Poisson’s ratio, ν 0.4
Yield strength, SY 365.4 MPa Yield strength, SY 65 MPa
Tensile strength, SUTS 636 MPa Thermal expansion, α 65 × 10−6 K−1
Thermal expansion, α 11.65 × 10−6 K−1 Conductivity, k 0.135 W/(m K)
Conductivity, k 49.4 W/(m K) Specific heat, c 1250 J/(kg K)
Specific heat, c 477 J/(kg K)
S.H. Tang et al. / Journal of Materials Processing Technology 171 (2006) 259–267 263
the products. Fig. 8 shows nodes selected for plotting time
response graphs.
Figs. 9–17 show temperature distribution curves for dif-
ferent nodes as indicated in Fig. 8.
From the temperature distribution graphs plotted in
Figs. 9–17, it is clear that every node selected for the graph
plotted experiencing increased in temperature, i.e. from the
ambient temperature to a certain temperature higher than
the ambient temperature and then remained constant at this
temperature for a certain period of time. This increase in tem-
Fig. 6. Loaded model for analysis of product.
contour plots of thermal or heat distribution at different time
intervals in one complete cycle of plastic injection molding.
For the 2D analysis of the mould, time response graphs
are plotted to analyze the effect of thermal residual stress on
perature was caused by the injection of molten plastic into
the cavity of the product.
After a certain period of time, the temperature is then
further increased to achieve the highest temperature and
remained constant at that temperature. Increase in temper-
ature was due to packing stages that involved high pressure,
Fig. 7. Contour plots of heat distribution at different time intervals.
264 S.H. Tang et al. / Journal of Materials Processing Technology 171 (2006) 259–267
Fig. 11. Temperature distribution graph for Node 302.
Fig. 8. Selected nodals near product region for time response graph plots.
Fig. 12. Temperature distribution graph for Node 290.
which caused the temperature to increase. This temperature
remains constant until the cooling stage starts, which causes
reduction in mould temperature to a lower value and remains
at this value. The graphs plotted were not smooth due to the
absence of function of inputting filling rate of the molten
Fig. 9. Temperature distribution graph for Node 284.
Fig. 10. Temperature distribution graph for Node 213.
plastic as well as the cooling rate of the coolant. The graphs
plotted only show maximum value of temperature that can
be achieved in the cycle.
The most critical stage in the thermal residual stress anal-
ysis is during the cooling stage. This is because the cooling
Fig. 13. Temperature distribution graph for Node 278.