Do you have some experience with 2K injection PC ovemolded by POM?

Dera Jiri
I am wondering why you want to overmould POM with PC. The are not very chemically bonded only If you will do a mechanical bond?

Dear Jiri,

In order to support you, can you share some information on the application? The combination POM-PC is not a very usual one. In addition to Vladi who made a relevant remark about the adhesion there is for instance also the large difference in mold shrinkage between the two materials to consider. This will have to be considered when designing the part. The high shrinkage of POM may result in high stresses on the PC part which may eventually result in stress cracking.

Dear Vladi, I do think so. There is problem that connection should be done mechanically. I am afraid that there could be an issue with tightness of connection under different temperature due to different thermal expansion. It seems that we have to do some prototype and test in case we need this application.

Dear Jan, thanks a lot for very useful comment related to shrinkage. Internal stress in the part is important point fo us because it can cause cracks if the part come in touch for example w/ gasoline.
In fact now we are in phase of kind of brainstorming and I don't have any particular application for this combination. I just want to know whether some of members of this group has already experience w/ this kind of resins combination. Anyhow, it is very nice to know that you are here and I can come to you in case I will need some support from you. I wish you successful day.

Jiri

Hi,
Do you mean molding POM over PC components?
We can do if so.
But it could be done double molding as one seamless molding as well.
You might as well the size of components and functions of the parts if you post.
Otherwise applicants who may not quality because of Injection molding size might to reply your posts.

Overmoulding PC with POM . Amorfe overmoulding by cristal material, different shrinkage, different temperature settings e.g machine and molds, different demoulding temperature. Yes it is possible but not that easy. Product design: POM should be mechanical fixed to the PC material during injection moulding ( chemical bounding is not Always possible)

The best combination with PC is ABS, SAN,PBT, PSU, TPE and of course PC.

With POM - the only good combination is POM and it has poor adhesion with most of the plastics.

Overmold design with some locking could work.
Did not find in internet if anyone has tried it.

But if you plan to try please share the results in the forum.

We all would appreciate, me the most.

Thanks

Not a normal application. As with all over moulding with a high shrinkage high mechanical strength material onto a hard plastic or even steel one needs to design the product that allows the over moulded material to shrink without distorting the over moulded material.