Insert Molding of a Stainless Steel Tube

Hi,

This is a pretty techie question but I was hoping someone on this forum had some metal insert molding experience…

I am on a project right now that requires insert molding a stainless steel tube into a low durometer PVC part. We are trying to determine if we can get an airtight/watertight seal between the stainless tube and the PVC. So far we have not had a lot of luck. Does anyone know of a substance that could be used to coat the stainless steel so that the PVC would adhere better and create a seal? How about geometry options? Our customer came to use with a polished piece of stainless but we are starting to look into knurled and grooved surfaces to create a better seal. Any suggestions? Thanks in advance for any help.

If you haven’t done so already, contact these guys:

www.mnrubber.com/

I don’t know about the specifics of PVC to stainless, but I know they are able to bond stainless to other elastomers and get a water tight seal. (suitable for medical apps)
Good luck!

Thanks for the info. I left a voicemail on the technical support line of Minnesota Rubber. Hopefully they will get back to me with some answers.

I have heard of insert molding stainless into other materials (ABS, other thermoplastics, various elastomers), however, I have not heard about what they do for PVC. Unfortunately, our customer wants to stay with PVC otherwise I would choose another material. PVC is just not right for this application in my opinion.

Anyway, I am just trying to elimate a step in the process by insert molding the stainless. It would save the customer a lot of headaches and product failures.

Thanks again.

what surface prep, if any, are you (or can you) do pre-mold?

i.e. bead blast, acid etch, etc.