New paint atomizer with over 95% coating efficiency | Hacker News Reader

New paint atomizer with over 95% coating efficiency

global.toyota

132 pointsclouddrover34 comments

I worked on a research project at Toyota in Toyota City. We were trying to improve the dynamic control of the rotational speed of their paint bells. There is a great deal of information about electrostatic paint bell systems on the internet. The overall process was very similar to the one described here: https://en.wikipedia.org/wiki/Rotational_bell_painting

During the last 20 years, the quality of Toyota's paint application has never been equalled, and they know it. I am not familiar with this new process, but it wouldn't surprise me if it were primarily based on small improvements to existing methods. After many years of working with Toyota, I can tell you that the superiority of their products is seldom due to new technology, but rather their dedication to perfection.

Note that electrostatic coating per se is ancient. That part is certainly not what is new here.

https://en.wikipedia.org/wiki/Electrostatic_coating

I suspect the "electrostatic atomization" is just a consequence of the rotating cone head flinging particles of paint off its edge, which then end up pulled into the electrostatic field that is already there for the sake of electrostatic coating; i.e. that the main invention is the rotating head.

Nope, the way it's described I'm certain this is electrohydrodynamic jetting. It's been well researched since first discovered in the 60s by G.I. Taylor (IIRC). And it's already used in inkjet systems.

From the description here, sounds like they have 600 of these droplet spray generators mounted in a conical assembly, which they rotate to keep feeding in paint via centrifugal force.

Here is a slow motion video of a system similar to one drop generator. Lots of parameters that Toyota could play with here, like geometry, field configuration, field strength, pressure etc.

https://youtube.com/watch?v=egi0t94wdcc

That's not a Taylor cone they have.

They have something in between true electropaint, and rotary atomizer.

What is the exact advantage over plain electropainting is unclear to me

This seems like an "emperor's new clothes" press release. How is this "revolutionary" compared to regular electrostatic coating processes that are already as efficient?

https://en.wikipedia.org/wiki/Electrostatic_coating#Process_...

I think there's some imprecision in language going on here.

Yes, that page claims that the system efficiency of current state-of-the-art electrostatic coating booths is 95%, through a combination of electrostatic attraction and paint recovery equipment.

I think Toyota is saying that 95% of the paint ends up on the piece on the first pass.

But just to make things extra confusing, the source material for the Wikipedia page already has a section on rotary nozzles:

> Rotary atomizers are one of the possible methods of atomization used with electrostatic coating processes. Instead of air or fluid pressure, rotary atomizers use centrifugal force to atomize coating material. As a general rule of thumb, the faster the rotational speed, the greater the centrifugal force and the finer the atomization.

So I still have no idea what it is they're claiming.

Seems novel in that they are combining the best of current rotary atomizers and electrostatic guns, and removing the need for compressed air.

If you look at current electrostatic guns, they mostly seem to use compressed air to atomize the paint. Rotary atomizers still use air to direct the paint to the surface.

So they get better transfer efficiency through electrostatics, and the rotary atomizer part probably allows them to use paints with lower VOCs further reducing emissions.

That said it does look like there already exists rotary atomizers that also use electrostatics. But also still use air.

https://www.graco.com/us/en/in-plant-manufacturing/solutions...

My dad worked for a company that manufactures electrostatic painting devices. They had high speed rotating atomizers in the 80s, possibly earlier. In the early 90s they started using air bearings, wherein the rotating parts are magnetically coupled with strong permanent magnets and separated by compressed air.

Am I the only one who is just learning there is a dot Toyota TLD now?

http://data.iana.org/TLD/tlds-alpha-by-domain.txt List of TLDs, large enough companies usually have one, I’m not aware of what the utility of having a TLD is to a non tech company

Maybe their cars updates are only allowed to go to .toyota domain names? That’d make it easier to not have your domain name expire on some URL your car is hitting and it gets taken over by squatters or something. At least that’s what I’d do.

Ah yes, why worry about forgetting to renew a $10 domain name when you can forget to renew a $100,000+ top level domain!

Probably works well to prevent phishing or spoofing attempts

This is a bit misleading. The efficiency measure refers to the percentage of paint that adheres to the car body. While a higher percentage of paint is “wasted” in the conventional painting process, almost all of it is reclaimed and used to paint other cars.

Wait. How does this work? I have an small spray gun that I use for small metal and wood projects that I hook to an air compressor. It can be used for smaller detail work on cars. Is there a way to reclaim my paint or is this just for larger industrial processes?

Electrostatic painting has existed for well over 50 years, I doubt there's much difference in efficiency with this system: the parts and paint are at tens of kV of potential differential, the paint has pretty much nowhere else to go.

The main issue with such painting technology is the homogeneity and size of the droplets or powder clusters.

They are comparing this new method to an Air Paint Atomizer.

The vast majority of spray painting today is with airless paint atomizers, where the paint itself is compressed and sprayed without the use of air.

Not precisely relevant to the “innovation” in the article, but is there any smaller-scale application of electrostatic paint deposition in the form of some kind of hand tool?

I.e. is there an electrostatic version of an airbrush, that doesn’t require a compressor, but rather (presumably) a voltage source alligator-clipped to the paint tank and the work surface?

I can’t picture quite how such a thing would work, because I feel like the paint wouldn’t really have enough energy to jump out of the nozzle on its own.

What you are talking about would be a powder coating gun. They use compressed air to spray the powder.

https://www.powdercoatguide.com/2012/11/getting-into-powder-...

Claiming that Toyota Group produces 7 percent less CO2 emissions just because of a change to the way paint is applied...? I don't believe it...

Reminds me of this: https://m.youtube.com/watch?v=oDrYkwG6Tuo

Guess we won't get any more fordite

Can they use this to paint custom graphics on a car's surface? How many DPI can they get?

.Toyota? they have their own TLD?

It’s a so called “dot brand” tld. Google, Apple and many others have them as well.

And for a mere USD$185k, you can have one too!

That feels like a bargain. Before I knew how software worked I thought TLDs were sacred.

They used to be, then ICANN lowered their standards.

So ugly, ICANN literally sold the internet.

Sadly, this doesn't work: https://toyota./

I recall touring plants where paint is sprayed onto charged bodies to help them stick rather than scatter onto other surfaces. What makes this any better?

Elon Musk shrugs.

Why do I care about this?

Isn't this a bit ironic that Tesla decided they offer the cybertruck in sheetmetal. As in every color you like as long as it's sheetmetal. Toyota has its own peak innovator dilemma moment here and they even brag about it.

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