Does anyone know the name of the material they use to slab coins

I mean the material on the inside of the holder that holds the coin.

It seems like some kind of rubber or PVC... just wondering what the actual products name is... I am assuming that material is a good as the coin companies use it and know it wont interact with the metal of the coins.

I broke down and purchased a Mahew 66006 set of hollow core punches. A little crazy expensive but I hate coins that spin in place in my coin books.

I hate when I have coins in a Dansco page that are smaller than the hole. With this tool I can punch clear plastic blanks to pin the coin against the plastic slide or make a "gasket" to hold the coin in the larger hole.

That is what is cool about this set, for many combinations of hole sizes you can punch both the outer and inner holes in one punch.


https://www.zoro.com/mayhew-pro-hol...6J_f38U4TWOsR_rdzEisXCuVOsD0allEaAsbXEALw_wcB

 

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Probably acrylic case and PVC free.

 

Hi
Thanks, but that sounds like the outside.... I mean the white rubber thing that holds the coin on the inside.....

Gary

 

I would've sworn it was common knowledge that those gaskets are a silicone elastomer, but I'll be darned if I can find evidence online. Guess the TPGs figure it should be a trade secret.

 

@-jeffB
Interesting... thanks I will try and check out sourcing such material....


This is an interesting product..... It is called Buna N Rubber and it is FDA approved for food applications. It is used for Gaskets and many other things.

Nitrile rubber, also known as NBR, Buna-N, and acrylonitrile butadiene rubber, is a synthetic rubber copolymer of acrylonitrile(ACN) and butadiene. Trade names include Perbunan, Nipol, Krynac and Europrene.

Nitrile butadiene rubber (NBR) is a family of unsaturated copolymers of 2-propenenitrile and various butadiene monomers (1,2-butadiene and 1,3-butadiene). Although its physical and chemical properties vary depending on the polymer’s composition of nitrile, this form of synthetic rubber is unusual in being generally resistant to oil, fuel, and other chemicals (the more nitrile within the polymer, the higher the resistance to oils but the lower the flexibility of the material).

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


https://www.ebay.com/itm/E-JAMES-31...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

I would imagine that the grading services try to keep certain processes secret to minimize counterfeiting. What do you think @Conder101 ?

Chris

 

Before you spend time and money, let me clarify: it might not be "common knowledge" that they use silicone because I'm completely wrong.

I expect that they're silicone, and I thought I'd seen posts saying so, but I can't turn up any evidence. So, it's quite possible that I just made it up.

 

No worries... I have bought small samples of a number of things to try.

Silicone rubber oven mat $6.49... got that :U)

Ebay under "LARGE Silicone Baking Mat Non Stick Heat Resistant Liner Sheet Pastry Oven Tray"

If its food safe and you can expose it to high temps.... its pretty stable stuff...

 

I don't know what they're actually made of, but any inert material would technically do. Silicone is a reasonable choice.

 

Thanks that is the kind of consensus I am seeking.....

The last thing I want to do is make a poor materials choice here....

 

Fake News..........

 

It could also be an expanded, ie soft polyethylene foam. This material is also completely inert and should not harm coins.
Silicone is as mentioned another logical choice. It can be well tailored for many applications from foam to hard elastomer. If properly formulated it is completely inert.

 

I think polyethylene foam is what makes up the rings in Air-tite holders. The only disadvantage I can see is that the foam might take on moisture (although I have not seen evidence of such using Air-tites, so maybe not).

 

I don't think polyethylene can take on moisture, especially if it's closed-cell (which I think those inserts are). Open-cell might hold some water, but neither one really attracts moisture.

 

Plastic

 

That is correct: polyethylene is non-polar and as such it will not bind water/moisture. Furthermore the cells are predominantly closed so that the outside surface of the foam is essentially impermeable to moisture.

 

And space age at that....

 

The actual makeup I am almost positive is proprietary and varies a little bit from each TPG. That said PCGS does have (or had) a patent on their new slab design but I don't think they had to disclose the material composition for it