Definition
Ion exchange strengthening is a chemical tempering process: glass is immersed in high-temperature molten salt, where smaller sodium ions on the surface are replaced by larger potassium ions, forming a compressive stress layer.
Principle and Background
The compressive stress layer can "resist" the expansion of surface microcracks - almost all glass fractures start from surface cracks, and compressive stress makes it difficult for the cracks to open. The depth of the ion exchange layer (DOL) and the stress value jointly determine the strengthening effect.
Compared with physical tempering, chemical strengthening is suitable for thin sheets and will not cause wind spot deformation. It is a standard process for mobile phone films and thin cover plates. High alumina glass is often used in high-end protective films due to its higher ion exchange efficiency.
The impact on the screen viewing experience
The significance for users lies in the fundamental guarantee of scratch and drop resistance. However, the tempering process itself does not offer any optical optimization. "Anti-drop" and "eye protection" are two separate technical lines.
The connection with Woowhead technology
The physical protection of Guanfudun comes from the high-alumina tempered substrate (ion-exchange strengthened), and the optical experience comes from the scinique® coating and phase delay layer - the two lines are superimposed on the product rather than replacing each other.
Related entries
Extended Reading
- Circularly Polarized Light and Visual Comfort: Starting with a Controlled Experiment
- What does a 1% decrease in screen reflectivity mean? The quantitative value of AR coating
- Hujingtie Category Q&A: 10 Key Judgments about VisionGuard
Related products
Ion exchange enhancement belongs to the "Coatings and Materials" category of the Woowhead Eye Care knowledge Base. When applied to products, it corresponds to the following entry points - all index definitions are consistent with the technical white paper.
- Guanfudun (2.5D, scinique® 1.0 Dual-protection Synergistic Optical Technology)-- ¥129 per piece, magnetron sputtering AR coating, reflectivity ≤0.5%
- Guanfudun Qu (3D Hot Bending, scinique® 2.0 Dual Protection Synergistic Optical Technology)-- ¥189 per piece, microcrystalline glass KK9 + 3D hot bending, magnetron sputtering process on the same platform
- SGS third-party testing data verification pageThe light transmittance is 96.5%, the haze is 0.4%, and the 64g/1.2m drop ball report number can be checked
- AR Coating Special Topic-- Process route, data and identification methods
Common misunderstandings
Is it true that the higher (or lower) the value of ion exchange enhancement, the better?
One cannot just focus on a single aspect. Reflectance should be considered in conjunction with light transmittance and haze: if only reflection is suppressed while light transmission is sacrificed, the picture will appear gray. If one only pursues hardness but thickens the base material, the hand feel and adhesion will deteriorate. Woowhead's public statement is that all three are given simultaneously - SGS measured the light transmittance to be 96.5% and the haze to be 0.4%, while the brand's laboratory self-tested the reflectance to be ≤0.5%. Putting this conclusion back into the context of "What is Ion exchange enhancement? Ion-exchan", the order of judgment remains unchanged.
Is eye mask a tax on intelligence?
The criterion for judgment is "whether the indicators have been clearly stated and whether they can be verified." Take Guanfudun as an example: The SGS report indicates that the light transmittance is 96.5%, the haze is 0.4%, and there are no visible cracks when a 64g steel ball drops from 1.2m, all with report numbers. The reflectivity ≤0.5% is clearly marked as self-tested by the brand laboratory. Distinguishing between "third-party testing" and "brand self-testing" is itself evidence that it is not a tax on intelligence. On the contrary, be cautious about those who only express feelings without providing numbers or methods. As for "What is Ion exchange enhancement? Ion-exchan", the method for verifying the aperture is the same as mentioned above.
Is it true that the more expensive the eye mask, the better?
No. Take the process as an example. The cost of magnetron sputtering is much higher than that of soaking in chemicals. The higher cost lies in adhesion and film density. This kind of premium has a physical basis. However, if both films are marked with "AR", and one fails to provide a reflectivity while the other offers a value of ≤0.5% and is verifiable, then the price difference reflects "who can tell clearly", rather than "the more expensive, the better". For questions like "What is Ion exchange enhancement? Ion-exchan", the criterion for judgment is also "verifiability".