comparing warpage

[kulandaivel_palanisamy]

Dear Users,

I want to compare warpage of a part with different injection locations (ex. pin point gate, Submarine gate & edge gate). Is it ok to put only the injection cones (with out feed) to compare the warpage. I am using Glass fiber filled PA6.

I understand that the Feed system pressure, Clamp force & shear rate will vary based on the actual feed system. What may be the difference between simulation with injection cone & simulating with feed system?

Please do share your experiences.

Thanks & Regards

JK

[nordhb]

Hi,
intially it should work fine to use injection cones only, as doing analysis of warpage trends.
When decided for the best gate location, add runner system to confirm the results.

Using the injection cones only means you will not get information what happens in gate, no entrace effects can be analyzed.
Adding feed system you will get more information on pressure drop, shear heating, gate freeze off et.c.

Regards,
Berndt

[JCourter]

Hello JK,

To add to what Berndt said.  Another thing to consider is mesh type.  The recognition of an injection cone differs between 3D and Dual Domain/Midplane.

That is Dual Domain and Midplane only recognize the injection cone as a starting point for flow.  Essentially excluding any affect the gate and feed system would have on the part.

3D on the other had will recognize the existence of a gate, the size of which is dictated by either a specified value (Process Settings-->Advanced Options-->Edit Solver Parameters-->Fill+Pack Tab-->Solver Setup-->Solver Parameters-->Gate Contact Diameter) or by the surface area of elements the node selected contacts.

Other than that, to get an idea of trending, etc. for comparison sakes running without a feed system should be sufficient in most cases.  Recognize though, there will be the potential unique scenarios the affect of the feed system is significant enough that it's exclusion could be problematic.

-Justin

[kulandaivel_palanisamy]

Thanks to Berndt & Justin.

[kulandaivel_palanisamy]

Dear all,

In moldflow there are different analysis sequence. I like to get clarified the difference between

1. Filling + Packing + Warpage

2. Cooling + Filling + Packing + Warpage

I guess, Incase of new part development, mostly it will be F+P+W. and incase of mold validation it may be with C+F+P+W.

If I am doing only F+P+W with out considering cooling channels, how moldflow calculates the warpage and

if I consider C+F+P+W with cooling channels, how the warpage calculation works and what will be mold temperature for these two options plays a role in warpage calculation.

I'll appreciate your comments.

Thanks & Regards

JK

[Anonymous]

Hi JK

If ur using moldflow 2012 you can use the transient cooling option to simulate cool +Fill+

pack+warpage

IF u don't have any info how ur cooling is going to be u can use F+P+W analysis

difference will be the solver will simulate cooling analysis first based on ur process conditions and will give Temp Mold and Temp Part. This Temp result is thermodynamic condition of equilibrium so that after some number of cycle the mold reached a temp distribution

Transient cooling also have 2 options 1 is within cycle cooling and 2 nd is moldflow tells us how many cycles needed

The drawback of this analysis is if ur mold is hot runner mold Moldflow can not simulate the heating phase of you are hot runner system so it is a Transient cooling analysis and not Transient heating.

Generally the Temp play inside a Moldflow is 1 st cooling and after that thermal heating a after both we will reach thermodynamic condition of equilibrium.

In short wt u can simulate is a normal cooling analysis based on beam element the solver is BEM Boundary element method

of u can go for transient cooling analysis

the Temp Results from cooling analysis will be used for filling and packing. So the Cooling analysis is not directly connected to Warpage but via filling and packing and temp distribution in filling and packing will effect Warpage

Take care

[GalSherbelis7635]

Hello,

Fiber orientation is greatly effected by the fill pattern. If the feed system greatly affects the fill pattern then you must model it. It is generally true to say that if your feed system is unbalanced you should model it (because the injection cones impose an "equal pressure" at all gate locations).

Regards

Gal