Absolute filling profile: Flow rate Vs time

[riomilo]

Dear all,

in February I performed a F+P simulation with an absolute filling profile (Flow rate Vs Time).

In that simulation, the machine screw diameter was not defined, but the simulation run without error.

Today, I wanted to repeat the simulation, but this time an error message appeared because the machine screw diameter was not defined. Why the machine screw diameter should be defined if the flow rate is already given? From my understanding, the flow rate at the injection point should be a sufficient border condition for running the simulation, independently from the screw diameter. Isn't it?

Thank you in advance for your responses.

Best regards,

Camilo Cruz

[mayur_dhumal]

Hi Camilo,

Can you please paste the error message number here to understand the problem?

If you have selected a different Injection Molding Machine than the default then you need to enter values for 'machine screw diameter' otherwise run as default setting. Your answer may be here, Please refer this link:

http://help.autodesk.com/view/MFIA/2014/ENU/?guid=GUID-D919B00E-9B4A-4254-AC89-D5362AF52DAC

Thanks,
Mayur

[madhukeshwart]

Error is attached as below & it will be for default machine too

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[riomilo]

Thank you for your answer.

The error number is 99644: No value was found for machine screw diameter for the selected injection molding machine.

I understand that once I define the machine screw diameter, the simulation will run without problem.

Nevertheless, my question is a bit more fundamental.

Why should I define a machine screw diameter if the flow rate is given as parameter?

In fact, the flow rate should be independent from the machine screw diameter.

Best regards,

Camilo Cruz

[mayur_dhumal]

Hi Camilo,

Default machine does not have machine screw diameter values, so even if you keep default setting 'Absolute Filling profile' will give error.

If you don't want to enter any values in machine screw diameter then you will need to select 'relative filling profile.

Relative profiles apply ram speed as a function of the total shot size or stroke, which are determined from the geometry of the part, the runner system and the gate. Relative profiles are usually used when the actual injection molding machine has not yet been selected.

Absolute profiles are used when key machine parameters are known, such as screw diameter and maximum injection rate. By running an analysis with an absolute ram speed profile, you can compare simulation results with actual results obtained using the molding machine.

Yes I got your question correctly.

Thanks,
Mayur

[madhukeshwart · Accepted solution]

. The starting ram position defines the shot size. If this ram position in the profile does not match the shot size, the profile will be extended to or cut off at the starting ram position value.