Overmolding TPU or TPE onto PP or Nylon HELP

[Cupsy]

Hi,
We have a base shell that is currently made of PP, and we anticipated using TPE for the overmold drink retainer flaps, however in testing the TPE has way too much surface friction, which causes the flap to stick to the drink container and invert as the container is removed.

Thus, we tried overmolding TPU(which seems to have lower surface friction) to the PP with poor results.

Thus, can you guys suggest some material combinations that may work? We need the retainer flap to have low surface friction and be overmoldable onto the shell. Thus, my thought is to try a Nylon6 shell with TPU retainer flap overmolds - thoughts?

other ideas?

Thanks,
Mark

 

[Demon3]

Add some ultrahigh molecular weight silicone as a drop-in solution to reduce friction. UHMW silicones are preferred because they do not migrate which is a major problem for regular silicones. Suppliers are Excista.com, Dow Corning and Wacker.

Chris DeArmitt - PhD FRSC

Plastics & Materials Consulting

http://www.phantomplastics.com

Plastic Training Seminars

http://www.plastictraining.com

 

[Cupsy]

Do you have a recommendation regarding how much UHMW silicone to add, and which brand might work best in our injection molded TPE setup?