Rigid PETG Meets Flexible TPU: A Custom Stopper Without Glue

A customer brought TECHNAST a stopper that needed two very different behaviours in one compact part: a solid body to hold its geometry and a flexible end to provide the stopping action.

The previous construction depended on a soft section attached with glue. We rebuilt the part as a multi-material print, combining a rigid PETG body with a flexible TPU contact section and fusing the two materials together during production.

The challenge: rigid support and flexible contact

A single rigid material would not reproduce the flexible end. A fully flexible part would not provide the required structural body. The solution was to assign each material a specific job:

• PETG body: the solid structural portion of the stopper.
• TPU end: the compliant red section that flexes at the point of contact.

Two materials fused into one part

The gray PETG section and red TPU section were printed to meet at a designed interface and fuse into one component. That removes the separate adhesive assembly step and the glue joint the previous stopper relied on.

This is where multi-material 3D printing becomes practical engineering rather than a cosmetic feature: the material changes exactly where the required behaviour changes.

Flexibility where it matters

What this project demonstrates

• A replacement part can combine rigid and flexible behaviour without making the entire component from one compromise material.
• Material selection can be localized to the job each section performs.
• A fused PETG-TPU interface can eliminate a separate post-print gluing operation.
• Physical references can guide the development of a practical custom replacement.

Need a rigid-flex replacement part?

TECHNAST provides custom 3D printing and engineering support in Markham, Ontario. If you have a worn, discontinued or application-specific part that needs more than one material behaviour, talk to the TECHNAST team or send us your project details.