Adhesion problem in Injection molding

[Anonymous]

Hello Sir,

I am a Phd student that currently involves the numerical modeling of coinjection molding of Polymers. I just would like to know how the Moldflow captures or models the adhesion of the molten metal and mold interface. Is there any simulation tool available in the market that helps in this aspect.

Thanks

[PipePakPat]

You are close to posting your question in the right forum, but not quite there yet.  You will get much more helpful replies if you post to the Autodesk Simulation Moldflow Advisor or Insight forums.  This forum deals with Simulation Mechanical and Multiphysics (Algor) software.

[Anonymous]

I have not 100% got whether you are interested about

• Conditions on the plastic-mold interface during filling/packing/cooling
• Prediction of the effect of adhesion/friction on ejection forces
• Strength of the bond between coinjected plastics

Each one is a separate problem.

Regarding  plastic-mold interface during filling/packing/cooling Moldflow usually assumes that plastic sticks to the metal if the pressure is positive and unbound from the metal if pressure is zero or negative. In "2013 Scandium technical preview" (the most recent technical preview) we can simulate Wall Slip. Currently, we can assume that plastic slips if the pressure is below some threshod and/or the temperature on the contact is above some temperature threshold

Moldflow currently does not do ejection simulation but it is possible to do it using combination of Simulation Moldflow, Simulation Mechanical and Autodesk Moldflow Structural Alliance. 

Moldflow currently does not predict strength of the bond between coinjected plastics (or the strength of the weldlines). There are some works correlating Moldflow predicted parameters (like pressure history, convergence angle, temperature, etc.) with the properties of the bond. You can google for those works. I do not have my own experience in saying how accurate the prediction is.