Material Selection for Interior Trim Clips: Metal vs Plastic 1

[Jonwhardiman]

Hello everyone,

I am a new design engineer for automotive interiors. I was recently tasked with a cost reduction activity to find out what is the criteria for switching from a metal clip to a plastic clip. I understand that it depends on the oem requirements as well as the interior commodity as some areas where there is airbag deployment may prohibit the use of metal clips. However, I would like to know what is the general guidelines for material selection of clips. For example, let's say that the customer drawing specifies for a trim clip that is metal, but I can achieve the same functional properties with a plastic clip. What are the design guidelines or criteria that should be considered when deciding between metal or plastic? Ex: Stress/shearing analysis, assembly/interfacing of adjacent parts etc. I realize that this might be a vague question, however, I am just hoping to receive some direction on what I should consider. I really appreciate any advice, literature, or help that anyone can offer here. Thanks in advanced for your time and consideration!

 

[MikeHalloran]

For a long time, it was metal clips from Tinnerman.
They could be a bitch to get out, they scratched the paint, and they scratched people.

Then it was 'christmas tree clips', which pushed in easy, didn't scratch the paint, and were cheap.
But they were a bitch to get out, and often caused catalyzed injury to technicians, even with special tools, and they were a one-time use thing, so technicans had to stock replacements.

Now it seems to be beautiful, sturdy, integrally molded liftoff clip/hooks. Buzz out a couple of screws, give it a bump here and there, and the door panel just lifts right off without damage or injury, and goes back in reverse order with no new material except a little extra weatherstrip cement on the rain shield.


Someone has been paying attention to repair costs.


Mike Halloran
Pembroke Pines, FL, USA

 

[Jonwhardiman]

Mike thanks for that information! That's some history I wasn't aware of. I still see the Christmas tree clips in-use for some of the current models (Some are metal, some are plastic), either way they can definitely be troublesome to remove. And you are absolutely correct, Serviceability can be a little pricey when you break a couple of clips and have to replace a whole door panel. I do wonder sometimes if that is conveniently the design intent; Or inconveniently depending on how you look at it, or who's making the ($) I guess.