Why the Flexible Protective Hardcoat on the Fold Looked Like a Removeable Protector
May 13, 2019
Some early testers of the Samsung Fold mistakenly removed the protective plastic hard coat installed by Samsung to provide the equivalent of a foldable “Gorilla Glass”. The question is; Why did Samsung use a tough film that doesn't completely cover the corners, so it looks like a removable protector?
We previously reported that Samsung collaborated with Sumitomo Chemical to produce a touch transparent polyimide (PI) that bends numerous times without any visible changes. However, Korean media said that it is not only the transparent PI that Samsung used for the first Fold batch, but actually something new and extra from Segye, SKC and Samsung SDI that co-developed an extra layer of protection, which was then applied to the Galaxy Fold. This Hard Coat Anti-Fingerprint (HCAF) film by Sekyung sits at the very top of an SKC-made PET layer, to which a Samsung SDI Optically Clear Adhesive (OCA) is applied that then gets fused to the clear and transparent PI film by a company called Biel Crystal. The reason that the top HCAF film that Samsung Display developed from scratch has been mistakenly considered for a "user-removable part" is that for added flexibility it is not tucked under the bezel. Needless to say, the publication says that "it is so tightly bonded that removing the film will require significant physical strength," and that the whole stack is actually the foldable screen package itself, so "removing the film means that the display is damaged to the point where it cannot function."
That top HCAF layer is actually what provides the final protection of the Galaxy Fold screen, as it best mimics the oleophobic glass cover used on most phones, rather than if there was only a transparent and flexible but soft PI film. Regardless of the design mishaps many phone makers have expressed interest in the new flexible display package developed by Samsung: This structure has not been previously available to the display industry for years, and Samsung is the first to introduce it, so it is inevitable for late buyers to get interested.
Previously, we reported that the PI film is simply attached to the OLED screen underneath with an extremely durable and flexible adhesive which allows the package to bend at the middle by stretching a bit but not coming unglued and doing this many times while retaining its original size and form. But the new top Hard Coat Anti-Fingerprint layer was added, and the foldable display phones' top suddenly becomes a viable alternative to glass covers. If and when Samsung masters the naked screen corners and tiny particles getting underneath the screen through the hinge cracks, the protective film should work.
US regulations require that Samsung announce by the end of May whether they will fulfill pre-orders of the Fold. Samsung notified customers that if the Fold is not ready by May 31 and customers don’t extend their orders, the company will cancel the orders.