Apple’s iPhone Duo may look nearly crease-free when new, but its folding display cannot escape physics forever. According to an engineering analysis, repeated folding will eventually leave visible wear along the center of the screen.
However, that does not mean the display has a design flaw. Instead, Apple has reportedly used advanced materials and hinge engineering to delay the crease and control how it develops.
Ultra-Thin Glass Makes Folding Possible
A foldable display cannot use the thick glass found on a traditional smartphone. Instead, it combines a flexible OLED substrate with extremely thin layers of glass. Each glass layer is thinner than a human hair.
Moreover, sliding adhesive separates the layers. This design allows them to move slightly against each other whenever the phone folds. A single thick glass sheet would instead risk cracking or shattering.
Apple’s hinge plays an equally important role. It creates a consistent folding motion and helps distribute stress across the display. The document’s image on page 3 highlights the complex hinge structure beneath the folding screen.
Repeated Folding Eventually Creates Fatigue
Still, no hinge can eliminate material fatigue. Every opening and closing cycle places stress near the center of the display.
Over time, tiny cracks may develop around the hinge area. Some slight delamination may also occur as repeated movement adds cumulative wear. Therefore, the crease can gradually become visible and noticeable to touch.
The report says folding displays are generally designed to survive around 250,000 folds. That works out to more than 125 complete open-and-close cycles each day for five years.
A Crease Does Not Mean Screen Failure
Importantly, a visible crease does not automatically mean the iPhone Duo is failing. The analysis finds no current evidence that normal crease development should become a serious usability problem.
Drops and other impacts could accelerate wear, though. Therefore, real-world durability will become clearer only after customers use the device over an extended period.
