Coin Holders

[oh my florin]

Sorry I meant manufacturing them can be dangerous. Sealing them as intended by the producer would be fine.

Oh, I see.

Nah, not dangerous at all. These things are ultrasonic-welded.

Basically, you attach an ultrasonic horn with the shape of your weld to a transducer, then you stick your work pieces between the horn and an anvil and apply pressure. When you give it a pulse of roughly 20kHz sound energy, the contact point vibrates enough to melt the work pieces and fuse them together pretty much instantly, in the shape of the horn. The bigger the contact area, the greater the energy requirement.

You can make these welders yourself, using scrap parts. The only high-tech component is the horn, which has to be precisely tuned to the right frequency.

I've actually seen a small hand-held unit that could be used for crude 3D modelling. I think I was told it cost something like $300, but it was a while ago, so don't quote me on that.

Fair enough I was more imagining fume risks with heat sealing but sonic welding like what PCGS and NGC use would be pretty safe didn't know they could use it on lower density plastics tho neither how available they were.

[Fulvio]

[Fair enough I was more imagining fume risks with heat sealing but sonic welding like what PCGS and NGC use would be pretty safe didn't know they could use it on lower density plastics tho neither how available they were.

Ah... nah, there are no fumes from melting plastics. Well, as long as you stay in the safe temp range and don't burn it anyway.

Its still heat sealing really, the difference is the energy comes in the form of vibration rather than combustion or resistance. And since the heating is extremely localised, you can actually weld dissimilar materials safely. I remember some demo pieces they were letting us make at one of the trade shows (1970's or early 80's maybe), which had three layers, including a foam padding inside. Using resistance welding would probably have started a fire while waiting for the thick PVC backing to melt.

[runway]

I like oldcoinchest flips real professional