Specific Process Knowledge/Back-end processing/Polymer Injection Molder: Difference between revisions
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== Switch-over Type == | == Switch-over Type == | ||
The switch-over type is a very important setting! It has a significant impact on the properties of the sample. This setting defines when the injection-phase is done and thus when the machine will continue to the next phase of the injection molding cycle (after pressure / holding pressure). Since this setting defines when we consider injection is done it significantly affects the properties of the produced sample, in particular filling. | The switch-over type is a very important setting! It has a significant impact on the properties of the sample. This setting defines when the injection-phase is done and thus when the machine will continue to the next phase of the injection molding cycle (after pressure / holding pressure). Since this setting defines when we consider injection is done it significantly affects the properties of the produced sample, in particular filling. | ||
*'''Volume-dependent switchover''': A certain volume of polymer is injected. Note that the volume entered (3,2 cm<sup>3</sup> in this example) is not the volume injected, but the amount of polymer left after injection! Also note that changes in shot volume (the amount of polymer in the heating cylinder before injection) will also change injected volume unless the switch-over point is adjusted accordingly. Volume dependent switchover is particularly well suited for developing new injection molding processes (so you can gradually find the point where the cavity is almost filled and then work from there) or if you already know the exact volume of polymer required. | *'''Volume-dependent switchover''': A certain volume of polymer is injected. Note that the volume entered (3,2 cm<sup>3</sup> in this example) is not the volume injected, but the amount of polymer left after injection! Also note that changes in shot volume (the amount of polymer in the heating cylinder before injection) will also change injected volume unless the switch-over point is adjusted accordingly. Volume dependent switchover is particularly well suited for developing new injection molding processes (so you can gradually find the point where the cavity is almost filled and then work from there) or if you already know the exact volume of polymer required. | ||