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62

Title of question: Is there a technical reason why most touch screens use glass rather than plastic? Note the word "technical" and not "marketing" What are the reasons that most modern portable touch devices come with a glass panel on their fronts, rather than plastic or something else? Glass (as a cheap and common material) has a good dielectric ...


38

"Melts" isn't the correct term here -- that would involve heat. The vinyl boot on the alligator clip contains a solvent called a plasticizer that helps keep it pliable. However, it is volatile and its outgassing has also affected the plastic used in the breadboards. The solvent is a volatile organic compound, and is probably dangerous if concentrated ...


38

When decisions about consumer electronics are made, many reasons beyond technical come into play. There is no valid reason for a phone to be disassembled in 7 pieces in order to replace a battery, yet that's how one of the most popular phones is made. Mobile phones are as much a product of marketing as they are of electronics, and many design decisions ...


33

You mention cracking as a downside to using glass, but most touchscreens will encounter far more potential scratch-causing events than crack-causing events. Glass is highly scratch-resistant: at a Mohs hardness of 5.5, it's harder than anything else in your pocket (steel is around 4). Synthetic sapphire is even more scratch-resistant: at a hardness of 9, ...


27

Interesting. The PVC (Polyvinyl Chloride) composing the alligator clip insulator is only part PVC chemically, a good percentage of it is plasticizer. That's what you smell from something like a swimming pool liner or beach ball, not the plastic but the plasticizer. PVC can be a majority plasticizer by weight if it has to be very pliable. It's likely that ...


21

If your plastic pellets are getting charged, you can flood the inside of the silo with ionized air using a commercial generator. These are not uncommon in the plastics industry.


16

Glass is hard, and therefore brittle, so it shatters. Plastic (acrylic or polycarbonate) is softer, so more prone to scratches. It's certainly a possibility and some cheap phones have plastic touchscreens. But the underlying LCD behind the transparent touchscreen has to be made of glass, due to high temperature parts of the process. So that's still ...


7

Ok, I think I pieced the answer together from the comments I received, I'll lay out what I found here for anyone else that may find this on search. I'm very confident the material is Amide-modified Mylar heat-shrinking tape, commonly used for inter-winding insulation and outer covering of toroidal transformers. I found a supplier on eBay, which was the ...


7

The most commonly used plasticizers are phthalates and they are probably not good for you, and especially children Several phthalates are "plausibly" endocrine disruptors.[24] The long-term health effects of exposure to endocrine disruptors, such as phthalates, are unclear.[25] Authors of a 2006 study of boys with undescended testis hypothesized ...


6

You can't easily do what you ask since the problem is charge gets built up on the plastic particles. Since they are all enclosed in one uniform conductor, it won't matter what the voltage of this conductor (the tank wall) is. There will still be charges on the plastic particles relative to the tank wall. Changing the voltage of the tank wall will only ...


6

You could try to measure the weight of the container, using rather simple pressure sensors for example.


5

These are called bosses. A boss is a post with a hole that can accept a screw. If the boss is tall in relation to the diameter, it should be reinforced with gussets (those shapes on the side that help keep the boss from snapping off at the base). Sometimes the posts have molded-in or ultrasonically pressed in brass inserts that provide a thread. Edit: ...


5

Ionized air is frequently used for static control in industrial processes. If you simply google for "ionized air static control", you'll find many commercial products.


4

Your questions requires a bit more specification as to the technology behind the touch detection. Touch detection techniques vs. Materials Typically, plastic surfaces are resistive touch panels placed in-front of glass or plastic LCD screens. They have to be made from plastic (as opposed to glass) because they detect touch by deforming. The user's finger ...


4

It seems obvious that square holes will have a somewhat wider tolerance for a range of screw diameters, which is handy for hobbyists who have an assortment of screws laying around. The screw has to forge a thread for itself, and that means displacing plastic. If the hole is round, then it works best when the screw has a fairly precise diameter in relation ...


4

The normal process for applying ITO is vapor deposition: like 'fogging' a mirror with steam, but using a boiling metal alloy. The challenge in doing that with thermoplastic would be not melting it in the process. (There are some references on google to doing this at room temperature with a plasma instead, though). Recent advances in glass hardness mean that ...


3

EDIT: As the OP pointed out he really meant SQUARE holes, so this answer isn't a match anymore. Which brings up kind of a meta question: Is it considered good practice to remove an answer after it has been voted on but becomes somewhat irrelevant for the question? I hesitated to write an answer for a pretty obvious thing but here you go. The hole with the ...


3

No. Most types of plastic have the possibility of causing ESD problems.


3

If you know the cylinders volume, then you can use this to calculate the amount dispensed, and also weight if you know the weight/volume relationship of the plastic. I don't know what type of "cylinder" it is or how the plastic gets in and out of it, but I imagine some hacking with a stepper motor and rotary encoder could dispense the plastic and get you ...


2

Resistive touch screens are plastic Capacitive are glass - for capacitive touchscreen to work, there is wires manufactured on the glass itself - this up to just recently was possible on glass only so this is why it is glass. Also LCDs are from glass for the same reason, there are already plastic film LCDs but are pretty new (like flexible amoleds and ...


2

You can mount circuit boards on top of these holes, using short, self-tapping screws. I'm not a native speaker, but you might call them mounting posts (or something alike).


2

There was an extended discussion on this in the home shop machinists forum a while back. Answers ranged from "don't waste your time, replace the cable" to a half dozen ways to actually attempt to do so. My own take is that any repair is not going to be as reliable as outright replacement, but since/if you have nothing to lose, why not try?


2

I think this is the type of membrane keyboard where the metal is extremely thin. It's often not copper foil as you might expect, rather I think it's printed silver paste. Basically, it has no structural integrity of its own, relying on the plastic for that. If you rub away the surface of the metal, you quickly discover that the surface is all there is to it. ...


2

If the tube is plastic you could arrange plates of a capacitor around the periphery of the tube - under normal circumstances the dielectric of the cap is air but as the tennis ball passes, it is likely that the permittivity of the material of the ball will increase the capacitance - it might increase the capacitance by 30% if care is taken. Use a 1 MHz ...


2

Here's some history: Back in the day, almost all of the early touch (not-so-smart) phones used plastic displays. It was, in fact, Steve Jobs, who demanded that the first iPhones use unscratchable glass. He said that consumers would carry their smartphones with keys in their pockets and products which were easily damaged weren't acceptable from a ...


1

Looks like a 4 pin ZIF carrier. The arms probably flip up, which allows a fragile or flimsy component lead to be inserted. Then the arms would flip down and the assembly would plug into another connector. It may be used for transistors, or possibly for sensor wires. or It could be the core from a connector. It clips onto the end of a 4 wire cable, as ...


1

It is most likely a type of 4-pin transistor mount. Similar results can be found by Googling "TO-5 transistor socket".


1

You can buy glass with Indium-Tin-Oxide coating and etch it with 55% HCL at room temperature. The Adafruit item is out of stock, but it should be possible to find other suppliers. Thickness of the ITO is 1850Å. Etch rate is approximately 25Å (2.5nm) /second. Good results were reported using AZ 1350H photoresist. Total etch time would be less than 1.5 ...


1

Plastics have the tendency of giving up or collecting electrons (depends on the kind of plastic) and become positively or negatively charged. If this charge is disturbing a proces then you need to treat the plastic by adding surface conductivity thereby preventing this kind of behaviour. Such an additive could be moisture or anti-static spray. Such an anti-...


1

There are many ways of constructing a PCAP touchscreens and some of them are entirely independent of the glass material. In effect the touchscreen is a film attached to the coverglass (or plastic) so as long as the material does not mess with the electric field projected by the capacitive terminals the touchscreen is perfectly happy. On the other hand glass ...


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