In September 2014, Samsung released the first 3D curved glass phone – Samsung Galaxy Note Edge, at that time, 2.5D glass was already very mature. Although it was only a single-sided curved display, after a great success, Samsung S6 Edge was released in 2015 with a true hyperboloid 3D display. In 2016, starting from Galaxy Note 6, the 3D curved glass display module was fully applied on Samsung mobile phones, now the Samsung Galaxy S series are all 3D curved displays.
Nowadays, there are many more mobile phones with 3D curved displays in the market. Almost all major mobile phone manufacturers except Apple have launched their 3D curved screen mobile phones. The rapid development of 3D curved screens has also led to the fast development of 3D curved tempered glass screen protectors. So far, screen protector manufacturers have introduced various curved tempered glass screen protectors such as full-glue 3D curved tempered glass, edge-glue 3D curved tempered glass, UV-glue 3D curved tempered glass, anyway, the curved edges on the 3D tempered glass are all based on the processing of hot-bending technology. This guide will take you to know everything about 3D curved tempered glass screen protectors and their hot bending technology today.
3D curved edge screen protector & hot bending tempered glass
The hot bending process is originated in South Korea. With the rapid development of glass processing enterprises in recent years, related processes have been inherited and carried forward. Among the 3D glass processes, the hot bending process is undoubtedly one of the most difficult processes. From graphite mold design and CNC machining to the hot bending process, every step is a very big challenge for manufacturers.
The hot bending 3D curved tempered glass film is essentially a flat glass film that is softened by high-temperature heating, then it is annealed in a preset mold with a curved edge to form a tempered glass film with a curved edge effect.
Although the common 2.5D tempered glass film has a certain curvature on the edge of the glass, the whole is still a flat surface, while the two sides of the 3D hot bending tempered glass film are bent, which can completely cover the mobile phone with a curved screen. Compared with the 2.5D flat tempered glass screen protector, the curved tempered glass formed by the hot bending technology can perfectly cover the large curved surface on the edges, this is impossible for a 2.5D tempered glass screen protector.
Pros & Cons of 3D curved edge tempered glass screen protector
The 3D curved tempered glass screen protector has almost all advantages over other tempered glass films, it is thin, transparent and clean, anti-fingerprint, anti-glare, tough, and scratch-resistant. Different from the cold laser engraving 3D screen protector or the dispensing-glue 3D tempered glass, the 3D tempered glass screen protector made with the hot bending process can achieve large curve at the edges, all of the 3D curved tempered glass with hot bending tech is used for big curved display such as Samsung mobile phones, but not for the iPhone. Due to the characteristics of the hot bending process, the 3D hot bending tempered glass film can cover the curved mobile phone display completely without white edges. The hot bending process is the perfect 3D screen protector solution for the 3D curved display.
Although the 3D hot bending tempered glass screen protector is still a kind of tempered glass, because its edge is bent, its drop protection performance of such large-curved hot-bent glass is not good due to its curved edge, it is more fragile compared with the 2.5D flat tempered film.
The 3D glass processing technology is complex, hot bending is one of the most difficult processes. As a result, the cost of producing 3D tempered glass film by hot bending process is much higher than that of the 2.5D flat tempered glass film. Similarly, the sales price is much more expensive.
Another problem is the recognition of in-display fingerprints, especially Samsung’s ultrasonic in-display fingerprint sensor, the 3D tempered glass screen protector is unable to support Samsung’s ultrasonic in-display fingerprint sensor very well. The recognition rate is low or fingerprints are unable to be recognized at all after the 3D tempered glass film is applied.
For Samsung’s curved screen, the manufacturer of 3D tempered glass’ solution is to punch a hole in the middle of the tempered glass film, so that the finger can directly touch the display, this is to allow the sensor to recognize the fingerprint. But problem is that such a hole in the center of the display makes the phone really ugly, many users simply cannot accept it, they turn to find other solutions such as liquid skin films, other plastic & TPU films, or 2.5D tempered glass film for protector the display.
The reason why the 3D tempered film cannot recognize fingerprints on Samsung phones is due to the problem of the ultrasonic signal penetration ability. Adding a layer of film on the Samsung phone screen makes the ultrasonic fingerprints unable to detect and recognize fingerprints. In this regard, Samsung officials also stated that the ultrasonic fingerprint sensor under the screen of the S10 series can be affixed with a thinner traditional film, but it might be not compatible with the tempered glass film.
But how can tempered glass film manufacturers abandon such a big market for Samsung curved displays? At present, some manufacturers have launched an all-new full-adhesive 3D curved tempered glass screen protector without punched-hole, this type of tempered glass is applied with new back-adhesive in order to make the tempered glass film thinner so that it is able to support Samsung ultrasonic fingerprint sensor perfectly, but the price paid is high cost, which discourages some consumers.
The 3 different types of 3D curved tempered glass screen protector
There are 3 different types of 3D curved tempered glass screen protectors currently in the market, the entire backside of the 3D tempered glass film is coated with adhesive, this is the so-called “Full-Adhesive 3D Tempered Glass Screen Protector”; the side or edge adhesive 3D tempered glass is coated with adhesive at 4 edges of the film, the most area on the tempered glass is without adhesive, as a result, the edge adhesive 3D curved tempered glass is attached to the display by electrostatic adsorption; the UV glue 3D tempered glass screen protector is also a curved edge tempered glass, it is pasted on mobile phone display by a special nano liquid UV glue, with such liquid glue, the tempered glass film can be pasted on display firmly.
All of these three 3D tempered glass is made by hot-bending technology, just the back adhesive are different, check from here all details about them.
What is 5d curved tempered glass?
We have mentioned in another post, 5D curved tempered glass is just a gimmick by merchants, it is an advertisement showing users their tempered glass has very smooth curvature edges than others. But it doesn’t exist, you may simply consider the “5D” as “3D” or sometimes they just mean a “2.5D” glass.
What is the difference between a curved tempered glass screen protector and a regular one?
A curved tempered glass screen protector is usually a 3D tempered glass film use on a curved display like a Samsung hyperboloid display, what we say a regular tempered glass is usually considered as a 2.5D flat tempered glass, for example, all iPhone models are used by flat displays, they have a slight curvature edge but they are not a big curved display like Samsung, so a flat 2.5D tempered glass are regular ones used on iPhone models, some merchants also introduced their 3D tempered glass screen protector for iPhone models, those 3D tempered glass are not bent edges, usually this kind of 3D tempered glass is made by laser engraving process or dispensing glue process.
FAQ of 3D curved screen protector
Q: Does the 3D hot-bent tempered glass film have a good anti-fingerprint effect?
A: At present, plasma spraying is more common in the market. According to different customer requirements, the oleophobic coating can be electroplated. The hand-painted oleophobic coating has been eliminated by market demand.
Q: Will there be “white edges” happen on the 3D hot bending tempered glass film?
A: The so-called “white edges” usually happens on 2.5D flat tempered glass film, it is due to the bad contact between the tempered glass and the slightly curved display (like the iPhone display). What you see the “white edges” are the transparent edges of 2.5D tempered glass film. But it doesn’t happen on 3D curved tempered glass, as 3D curved tempered glass will fully cover the curved display, so you will no longer see the “white edges”.
The 3D laser engraving tempered glass or dispensing glue 3D tempered glass screen protector is applied to flat screens such as iPhone to solve the “white edge” problem. The slightly curved edges on 3D laser engraving or dispensing glue tempered glass film are treated with slightly contoured edges, the slightly contoured edges are designed to fit the edges of the display better in order to avoid the “white edges”.
Q: What is the price difference between 3D hot bending and laser engraving tempered glass film?
A: 3D hot bending tempered glass film and 3D laser-engraved tempered glass film are made by two totally different processes, and they are also used for mobile phones with completely different types of displays. 3D hot bending tempered film is used for large curved displays such as Samsung curved screen mobile phones. The 3D cold-engraved tempered glass film is mainly used for flat displays, such as iPhone. The main advantage of the 3D cold-engraved tempered film is that it fits well on the display screen with a slightly curved surface and does not produce white edges.
Both hot bending and laser engraving processing are two high-end processes on tempered glass, they usually apply on premium tempered glass screen protector products, and they are sold at relatively high prices.