stamping tiny cups from aluminum foil/sheet

We just got one of those capsule base coffee makers, a Nespresso- and it makes really good espresso shots.

But the coffee is only available from specific places.

The idea is similar to the Kuereg thing- a cupped shape capsule with coffee in it, and the water flows through it. The Krupps one does it at low pressure- like normal coffee, this one does it at high pressure (19 bar) like espresso.

There are some fill your own options out there, and we may get one- since we have a local coffee maker that we like a lot.

But that's not what I'm looking to do.

I'd like to take a roll of the proper aluminum, stamp out the cups, fill them with coffee, and top it. The first step is where I'm stuck- how to stamp out the cups.

There are a lot of the single cup makers out there, but when looking into having the coffee guy down the street be able to make some of those things for the local market- you find that one needs to make 300,000 of them at the bare minimum.

I think it would be cool to have a small device that they can crank out small amounts to support the local market. While the idea of one just big enough for one small maker is ideal, supporting the 6-10 local (depending on the radius from HERE) is a fine option for a small company.

Anyone know anything about stamping very thin aluminum into cups?

(I can get plastic cups, but this is high pressure/temp and would rather see how far one can get using the material that Nespresso is using)

This cup is what I want to make.

You would think that aluminum especially untreated aluminum and coffee would take like crap; sorry. Coated in a proper food safe plastic I could see it working, plus without the coating you cannot do a heat topper.

Nespresso uses plastic right with a food safe coating on the inside and more then likely argon or neutral packed. You might be better off with a plastic vacuum molder for making the actual cup. You can use heat sealers like the boba guys do for the tops with just about any food safe material. You would think that packaging and selling this sort of stuff would have heavy FDA oversight its a packaged product after-all. They have astonishing reach over perpared products. Additionally you can run into DRM issues with the coffee guys. A lot of the big cup makers are based on paper oversea's to avoid just this.

You could machine a pretty east two part mold if you used metal and crank them out by hand reasonable quickly, say 200 a hour. Would need to heat seal or even better roll crimp the edges for a stable product. If its thin enough you might be able to vac form the metal but to fill and crimp would be expensive.

You are right about the coating- Nespresso uses a food shellac on the surfaces.

And if you look at them close, you can see that the upper foil is rolled over the outer side.

It's interesting that one can buy the cups that someone made from plastic, but not ones from aluminum.

So for the step one part- where would I read about making the mold?

Then to worry about the shellac would be step two.

Until I even have a solid idea how to make the cups, the FDA stuff is fluff. I'm sure it's about materials, and how to safely manage the materials for food consumption.

alfadriver wrote: You are right about the coating- Nespresso uses a food shellac on the surfaces. And if you look at them close, you can see that the upper foil is rolled over the outer side. It's interesting that one can buy the cups that someone made from plastic, but not ones from aluminum. So for the step one part- where would I read about making the mold? Then to worry about the shellac would be step two. Until I even have a solid idea how to make the cups, the FDA stuff is fluff. I'm sure it's about materials, and how to safely manage the materials for food consumption.

The mold you can look online for but you could do a product like that with hand pressure you would not even need a stamper. This is the easy part. The actual legality of selling a food product is outside my wheelhouse. Drugs and pharmaceuticals I can answer on reasonably well. Here is California we have a few rules in place for smaller food producers like jams and roasters who sell small batch but we are talking real small businesses. Mom and pop on the side of the road or at local coop markets.

In reply to wearymicrobe:

So I'm searching for the wrong thing, then- what proper technical words would get me a good web page? Doing it with hand pressure is exactly what I want to do.

The people I want to support are in the food business, so I'm hoping that once I get past making the capsules, I can get them to help figure out what the proper coating and application of that is, as well as material handling- for both the tools, the capsules, and the coffee.

take one apart and make a mold of the outside and mold of the inside. Use these to cast forms.

DaveEstey wrote: take one apart and make a mold of the outside and mold of the inside. Use these to cast forms.

I thought about that- but didn't think it would be that simple.

I know whatever I cast them in, I have to make the copy in a proper metal- and then get the finish correct. Then make sure the top of the die correctly cuts the sheet as the plunger comes down. I susepct that the process would be- shear the base form from the foil, and then press into the mold.

You can clearly see stretch marks in the aluminum- so that middle part is kind of fair game for stretch.

I like the idea of capping it with a small heat system, which would use the shellac as the sealer- some of the DIY cups use simple food grade adhesive- so it's not required to press the top down. On the other hand, a simple criming device (similar to a beer bottle top) requires no heat. And can be hand run- again running a foil sheet through the tool.

alfadriver wrote:

DaveEstey wrote: take one apart and make a mold of the outside and mold of the inside. Use these to cast forms.

On the other hand, a simple criming device (similar to a beer bottle top) requires no heat. And can be hand run- again running a foil sheet through the tool.

This is not exactly the simplest thing in the world if you need to keep the top of the cup uni-formally flat and not having wrinkles around the edges. Plus it makes the cap thinker usually for it to survive the crimping, which might be harder to poke through. Spinning edge crimp/folders are not cheap but they exist for a reason typically production or downstream requirements. I don't have one of those Nescafe cups around to look at right now or the machine. In some ways it might be easier to make and sell the espresso ones that are used in office buildings. We go through tones of the things here and it took us forever and a day to find coffee that was drinkable. Plus offices buy in larger quantities and this would be easier I think to make.

Other thought, buy a bunch of these and sell the coffee is small prepackaged aliquots that work with the reusable. That way you can say you are selling a less wasteful system and you get around the whole having to actually make the cup portion. Then all you need is a one ounce or similar packager with inert gas foil packager which can be found used pretty cheap on dovebid or any of the usual places. I would buy a roll of these for the wife in a heartbeat she drinks about four cups a day but never one right after another.

Do something cool like etch the cup with the roasters name and phone number like a business card.

1) Food grade stainless cup as shown above
2) tea bags w/ coffee in them in a sealed bag
3) Profit!

I was thinking you could make machine a set of steel dies that would simply be clamped in an off the shelf C-clamp, and you could simply stamp them out by tightening the clamp. You might need to use some guide pins outside it to line them up. You don't need a ton of force (literally) for this one.

But as Wearymicrobe noted, vacuum formed plastic may be a better option.

I work for a shop that specializes in aerospace sheetmetal.

That's a pretty deep draw. I would say you would have to start with your material in the O condition and then heat treat to final temper after forming.

You may be able to form it in 1 step with a match metal die but I'm thinking it might need to be a 2 stage form with an anneal process in between.

This type of job would be very crack/tear prone

The rolled flange could be done in seconds on a lathe

wearymicrobe wrote: Other thought, buy a bunch of these and sell the coffee is small prepackaged aliquots that work with the reusable. That way you can say you are selling a less wasteful system and you get around the whole having to actually make the cup portion. Then all you need is a one ounce or similar packager with inert gas foil packager which can be found used pretty cheap on dovebid or any of the usual places. I would buy a roll of these for the wife in a heartbeat she drinks about four cups a day but never one right after another. Do something cool like etch the cup with the roasters name and phone number like a business card.

I saw a pretty fair comparison of various fill yourself systems, and this one does not work that well.

One pretty important key to the Nespresso system is the foil top- it needs to be the right thickness to burst open at the right pressure. Which is part of the whole espresso shot thing.

The one you found has holes in the top, which doesn't do a good job for the pressure.

You can get some refillable systems that use a foil lid that looks quite good. This one is better, but I can do the same idea-

And, of course, IS and option.

But I also like the idea that coffee roasters control the entire aspect of selling their product- correct grind, amount, etc. Which goes for the Keureg system, too.

2002maniac wrote: I work for a shop that specializes in aerospace sheetmetal. That's a pretty deep draw. I would say you would have to start with your material in the O condition and then heat treat to final temper after forming. You may be able to form it in 1 step with a match metal die but I'm thinking it might need to be a 2 stage form with an anneal process in between. This type of job would be very crack/tear prone

So we are clear- this is pretty thin aluminum- where you can see that it's stretched in the middle area. Very easy to deform- but I suspect the only thinned part is the middle- the top and bottom appaer to be closer to the original aluminum thickness.

For the applucation- do you really think a heat treat is needed? The system is much like a gun cartridge- where the physical support in in the machine. The sides are totally held via the machine, the bottom is puncutred for the water supply, and the top gets punctured as it relases the hot fluid. And the top part is basically aluminum foil- thinner than HD foil you get in grocery stores.

Basically, the way the system works mechanically, if you can manage to stamp the form without tears, there's no obvious reason that a heat treatment would be needed to restore the metal properties.

Going off the reservation here a little here but could you print them up on a 3d printer and then coat the plastic with a food grade coating? Are there food grade plastics for 3 d printers?

In reply to dean1484:

I'm sure you could, but I'm hoping to come up with a simple system to make a bunch for a friend to sell in his coffee store for cheap. Nespresso sells basic capsules for $0.70, and $0.80 for higher end coffee, where another company sells what I want to do for about $0.60 a capsule. I may end up contacting them- but they use a plastic capsule.

2002maniac wrote: I work for a shop that specializes in aerospace sheetmetal. That's a pretty deep draw. I would say you would have to start with your material in the O condition and then heat treat to final temper after forming. You may be able to form it in 1 step with a match metal die but I'm thinking it might need to be a 2 stage form with an anneal process in between. This type of job would be very crack/tear prone

I agree with the metal being is the O condition, but it sure wont be after that stretch.

So I may be an engineer, but it's been at least two decades since I had materials classes, what's "O condition"?

(and I don't think material strenght is that important in the machine- as long as it doesn't melt)

alfadriver wrote: So I may be an engineer, but it's been at least two decades since I had materials classes, what's "O condition"? (and I don't think material strenght is that important in the machine- as long as it doesn't melt)

Tells you how soft the metal is. After being abused with hammers, bending and stretching, metal gets hard and brittle. It can be heated up and softened known as "Annealing".

I bet you the thing is patented or protected in some form.

This reminds me a bit of when I had the brewery and people wanted their beer in cans. It was quite doable and we did a lot of them, but the cans were like $0.60 each. Things that are designed to be cheap in large volumes tend to be very expensive in small volumes.

Is the cup exposed to pressure (as in a differential between the inside and outside or is it just "in" the pressure chamber? In one case it needs to hold the pressure, in the ther, the metal sees no forces from the pressure.

In reply to NOHOME:

I'm 95% sure that it's not subjected to stress- I need to look closer, but it looks as if the capsules fit into the machine much like how a bullet cartridge fits into a gun- the brass isn't really loaded in pressure- other than it expanding to fit and seal the chamber. The capsules are not that strong- if 19bar was actually applied to it, I think it would rupture pretty fast. That, and there are quite a few soft plastic capsules that do work (assuming that the videos are not faked- and they don't look it- it was a review of all of the fill yourself capsules).

I know that Nespresso thinks they are patented- but I've also seen some articles that they may be forced to "open source" them so that they are not the only supplier of the coffee.

Back to the aluminum- I would not be surprised that I'd have to lightly bake a roll of foil- so that it would stretch and form over tearing. I have seen that many fabricators do a quick heat treatment to soften the sheet so that it will take hammering. Just not my field of engineering.

2002maniac wrote: The rolled flange could be done in seconds on a lathe

Not with product packed it it its not going to be easy. If these things are being shipped they are pressurized with something inert. You really need a proper packing machine to do this.

I still am not entirely sure how the water pressure and cracking of the top seal have anything to do with the quality of the coffee. The top is cracked open the bottom is cracked open the only thing restricting the flow is the coffee pack. If that is the case make espresso tamper that fits.

In reply to wearymicrobe:

I'm not entirely sure, either, but when someone showed all of the various ways of packing your own- the ones that were the best were the ones with foil tops. Plastic mesh and metal mesh both made poor quality coffee, whereas the foil did much better- including the foamy crema that is a hallmark of espresso.

So it seems to me that the machine is at leat more compatable with a foil- if it's related to pressure or not- that's just my opinion.

As for what gas is added? I suspect N2- it's the most common food packed gas, and isn't reactive. Since the pods from Nespresso are good for a year, it's something, for sure.

It's possible that the whole packing environment is N2- with the size of the pods- it's probably not a big machine. Actually, someone in Austrailia makes a small packing machine for pods (using plastic containers), and it's pretty compact- about the size of a typical office desk.