Extending Flex Life 5× for a TPU Accordion Component

The Challenge

A global mobile accessories brand asked Simblong to improve an existing accordion-style expansion component.

The original sample developed cracks after repeated pressing, resulting in insufficient product life. Compression and rebound did not provide the expected user feel, while trapped gas caused visible molding defects on the product surface.

Simblong’s Solution

Simblong replaced the original material with a higher-durability TPU grade to improve repeated flexing performance.

The wall-thickness transition was adjusted through multiple design iterations until the required compression and rebound characteristics were achieved. The mold was redesigned with multiple venting inserts to improve gas release and reduce surface defects. During production, the mold surface was periodically cleaned with dry ice to maintain consistent venting performance.