How many of you have used SIGMASOFT simulation program? If you know of a good article that compares them along with Moldex3D please let me know.

I have demoed SIGMASOFT

Can you share your experience with it? Do you feel it does a better or an equal job as moldflow when it comes to fill+pack+cool+warp. The reason i am asking is that when i read the information on their website it comes across as a very powerful tool with some very advanced capabilities.

Hi Nishit. Which website have you read the information from? Do you have concerns that Moldflow solvers aren't providing good results? In my experience Sigma, Moldex and Visi haven't been a comparison to Moldflow in reality, but only on paper, where say so doesn't bring value add to the important decision making process that we are all faced with in reality.

I am a moldflow user (infact, an everyday user) and am quite satisfied with moldflow results (atleast for fill+pack) but there are some aspects where the results have been questionable and we haven't been able to match reality. Again, i dont expect 100% real-world matching and i understand some cases will be different but that is the reason i'd like to understand if someone else can fill in those gaps. Nothing wrong with that i believe.

Also, some of the advanced capabilities (transient cooling, post-molded shrinking, crystalization effets, ejection simulation, conformal cooling, etc.) that i was talking about are being introduced in moldflow as we discuss this but they have been in Sigmasoft for quite a while which in my mind gives them some credibility.

Also i have heard from some very prominent Hot runner manufacturers that Sigma soft does a heck of a better job at capturing shear imbalances in the runner system than moldflow.

Till date i have never been able to capture shear imbalances in a geometric balanced runner system using moldflow. I have done everything i can possibly think of for the mesh and follow every single recommendation but never had a successful result and that problem is one of the first examples on Sigmasoft's website. Now those things make me wonder is there something better out there...

I also wanted to bring up a another "glitch" that i dont think has been solved yet. A little while ago i was flowing a perfectly cylindrical barrel like part with two symmetric gates one on each side. I dont expect any core deflection but yet there was .004-.005" deflection in moldflow. I also send the model to support and they were satisfied with the mesh quality and how it was staged but were unable to explain the unexpected result. This make me nervous about using core-deflection at all cause i dont know when the results are good and when not...

Nishit - I believe Sigma can predicted shear imbalances is because it is using a 3D mesh for the runner and part (I believe, I'm a Moldflow user not a Sigma user). If beam elements are used in moldflow to model the runner the solver takes the midstream data and that is why a shear imbalance cannot be modeled and predicted. Moldflow can predict shear imbalances if the runner is modeled in 3D and you have at least 10 rows of elements. This creates a very large mesh, but I've been able to model such an imbalance.

As to your question of core deflection, I think one issue could be the symmetry of your mesh. I'm not sure what mesh you are using, but if the mesh is not symetric across all axis there will be slight pressure differences and this could cause some slight deflection.

Hello Erik,

I am moldflow user too and mostly 3D. I have spent a lot of time modeling the classic runner imbalance (fan gated, u-shaped, 8-cavity piece) in 3D using all of the mesh recommendations (10 layers, aspect ratio, iel, etc....) and an extremely high tetra element count, but have never captured the imbalances. I would love to see what you were able to acheive (if you can share an image).

As for the mesh symmetry, at the time moldflow support team told me that the mesh was not an issue as for why i was seeing the problem. But on a different note, i dont think you have too many options to ensure a symmetric 3D mesh.

I just sat thru a sigmasoft webinar yesterday and i asked some of the questions that i face problems with in moldflow and they seemed like a simple deal with sigmasoft. One of my questions was "Do we need any special mesh requirements to capture shear imbalances and other problems (jetting, etc.)" and they said you do what you are supposed to do for every part and it just analyses those conditions everytime.

I agree that moldflow resin library is the key here but simulated an advanced set of problems with relative ease is also important.

Again, i am not trying to judge or replace one with the other but instead meaningfully compare the various programs to see how they could complement each other.