I'm comparing injection molding and vacuum thermoforming for high wall automotive footwell trays, mainly using TPE-type materials.
From what I've seen, thermoforming obviously has a tooling cost advantage, but once you get into deeper draws, the material can thin out quite a bit around the vertical walls and tighter radii. I'm wondering how much that actually matters for long-term dimensional stability, especially after repeated hot/cold cycles inside a car.
Injection molding gives you more control over wall thickness, ribs, and local reinforcement, but the tooling cost gets pretty serious once the floor geometry becomes complicated.
For parts like this, how much of the warping resistance comes down to maintaining more consistent wall sections versus designing in ribs, radii, and proper stress relief?
I'm less interested in the cost side and more curious about what tends to keep the perimeter from slowly changing shape over time.