This is a quick and simple method for making your own general-purpose plastic. The constituent ingredients are milk and vinegar. That's it. The total cost is less than $10, possibly less than $5 if you can get a good deal.
The plastic is moldable, and has a consistency of soggy cheese (I certainly hope I never encounter cheese that's anything like this!). When all is said and done, it should take you about 10-15 minutes to make the plastic (less if you make a small amount), 10 minutes of cleanup, plus 2+ days to allow the plastic to dry. As always, your milage may vary.
As for the final product's strength and whatnot, I would classify it as "okay." If you roll it thin (as I did in this instructable), it can easily be snapped in half, though it will probably survive a small drop on to carpet. Thicker pieces seem to be more resilient against average abuses - no problem dropping on to carpet, and if it's thick enough, you wouldn't be able to snap it in half. A blow from a hammer or other such object would quickly shatter it, though.
All in all, I would say this is mostly useful for folks looking for a fast and dirt cheap alternative to much better products available to the average joe. It's definitely not for something that will be handled on a daily basis - good enough for light decor, not much else.
This is my first Instructable, so bear with. Constructive criticism is always welcome!
The plastic is moldable, and has a consistency of soggy cheese (I certainly hope I never encounter cheese that's anything like this!). When all is said and done, it should take you about 10-15 minutes to make the plastic (less if you make a small amount), 10 minutes of cleanup, plus 2+ days to allow the plastic to dry. As always, your milage may vary.
As for the final product's strength and whatnot, I would classify it as "okay." If you roll it thin (as I did in this instructable), it can easily be snapped in half, though it will probably survive a small drop on to carpet. Thicker pieces seem to be more resilient against average abuses - no problem dropping on to carpet, and if it's thick enough, you wouldn't be able to snap it in half. A blow from a hammer or other such object would quickly shatter it, though.
All in all, I would say this is mostly useful for folks looking for a fast and dirt cheap alternative to much better products available to the average joe. It's definitely not for something that will be handled on a daily basis - good enough for light decor, not much else.
This is my first Instructable, so bear with. Constructive criticism is always welcome!
Step 1: Ingredients & Utensils
This doesn't require anything fancy.
Essential Items:
Milk
Vinegar
Large Pot
Larger Pot (needs to be the same size as the other, or larger).
Spoon, preferably plastic or metal
Strainer or Colander, the finer the better
Stove or other item with which to simmer milk.
Paper Towels, lots and lots of paper towels
Handy, but not necessarily essential, items:
Wax Paper (good for rolling and shaping on. Water and other liquids bead up on it for easy clean-up; also non-stick with the casein)
Aluminum Foil (good for certain types of molds)
Rolling pin (if you're going to make a flat sheet of plastic)
Before you begin making the plastic, it's important to know what you're intending to make. By knowing what you're final goal is, you can make the preparations for the mold before you have a sloppy wad of plastic on your counter.
For this Instructable, I am making a curved piece that will fit on the front bezel of my computer case. Since this is beyond the scope of this particular instructable, I'm going to gloss over what I'm using. My mold is going to be the front bezel of the computer case, covered with aluminum foil. The plastic will dry nicely on top of it, and the aluminum won't shrivel or wrinkle when it gets wet as the plastic cures.
How much milk and vinegar will you need? The basic ratio that I follow is 1 TBSP of vinegar for every cup of milk. (16:1 ratio, milk to vinegar)
1 cup of milk will produce a puck of plastic about 2" in diameter, 1/8" thick.
To cover my case bezel, which is about 6 inches wide and 8 inches tall, I am going to use 8 cups of milk (and therefore 8 Tbsp of vinegar).
Essential Items:
Milk
Vinegar
Large Pot
Larger Pot (needs to be the same size as the other, or larger).
Spoon, preferably plastic or metal
Strainer or Colander, the finer the better
Stove or other item with which to simmer milk.
Paper Towels, lots and lots of paper towels
Handy, but not necessarily essential, items:
Wax Paper (good for rolling and shaping on. Water and other liquids bead up on it for easy clean-up; also non-stick with the casein)
Aluminum Foil (good for certain types of molds)
Rolling pin (if you're going to make a flat sheet of plastic)
Before you begin making the plastic, it's important to know what you're intending to make. By knowing what you're final goal is, you can make the preparations for the mold before you have a sloppy wad of plastic on your counter.
For this Instructable, I am making a curved piece that will fit on the front bezel of my computer case. Since this is beyond the scope of this particular instructable, I'm going to gloss over what I'm using. My mold is going to be the front bezel of the computer case, covered with aluminum foil. The plastic will dry nicely on top of it, and the aluminum won't shrivel or wrinkle when it gets wet as the plastic cures.
How much milk and vinegar will you need? The basic ratio that I follow is 1 TBSP of vinegar for every cup of milk. (16:1 ratio, milk to vinegar)
1 cup of milk will produce a puck of plastic about 2" in diameter, 1/8" thick.
To cover my case bezel, which is about 6 inches wide and 8 inches tall, I am going to use 8 cups of milk (and therefore 8 Tbsp of vinegar).
Step 2: Heat it up
If you've never heated milk before, it's important to know that if you heat it too fast, it will start to burn on the bottom of the pot. To bring it to a simmer, it's best to keep the heat down to about 50-60%.
I don't follow my own advice, and use full heat, because I don't want to wait.
While the milk is heating, be sure to stir it occasionally, so it doesn't burn. Also, if you're heating more than one or two cups of milk, measure the vinegar out into the cup while the milk is warming. This is personal preference, as it makes it easier to pour the vinegar in all at once, rather than measuring it out in a hurry.
During this time, you may need to pander to a needy cat, if one happens to be around.
When the milk nears boiling, you will notice a foam forming on top of the milk, as well as a little noise coming from the pot. Steam will start to appear too.
Once you reach this point, turn off the heat, pour in the vinegar, and stir. You will immediately notice chunks of casein forming. Stir it for another thirty seconds or so, for good measure.
I don't follow my own advice, and use full heat, because I don't want to wait.
While the milk is heating, be sure to stir it occasionally, so it doesn't burn. Also, if you're heating more than one or two cups of milk, measure the vinegar out into the cup while the milk is warming. This is personal preference, as it makes it easier to pour the vinegar in all at once, rather than measuring it out in a hurry.
During this time, you may need to pander to a needy cat, if one happens to be around.
When the milk nears boiling, you will notice a foam forming on top of the milk, as well as a little noise coming from the pot. Steam will start to appear too.
Once you reach this point, turn off the heat, pour in the vinegar, and stir. You will immediately notice chunks of casein forming. Stir it for another thirty seconds or so, for good measure.
Step 3: Strain
Slowly pour the heated liquid through the colander and into the larger pot. Most of the chunks of casein will get caught. We pour slowly to avoid splashing the plastic-loaded liquid into the sink. Something tells me that chunks of this stuff in the drain is not a Good Thing(tm).
Once you've poured it out (don't worry about what's left in the bottom, we'll get to that), gently shake the strainer, and swirl it around a little. Most of the casein will lump up in the bottom, pulling itself out of the holes. Make sure a majority of the liquid is strained out, but don't press it out -- the casein will just get stuck in the holes, and make it harder to get out.
Now that it's all clumped together, dump it out on some wax paper.
If you have a super-porous strainer like mine, you may want to pour the liquid through the strainer several times. Doing it a second time pulled a chunk about 1/4 as large as the original mass; that's a nice addition.
Once you've poured it out (don't worry about what's left in the bottom, we'll get to that), gently shake the strainer, and swirl it around a little. Most of the casein will lump up in the bottom, pulling itself out of the holes. Make sure a majority of the liquid is strained out, but don't press it out -- the casein will just get stuck in the holes, and make it harder to get out.
Now that it's all clumped together, dump it out on some wax paper.
If you have a super-porous strainer like mine, you may want to pour the liquid through the strainer several times. Doing it a second time pulled a chunk about 1/4 as large as the original mass; that's a nice addition.
Step 4: Sop up the excess
After you've strained all of the casein out of the liquid, you'll want to soak up some of the remaining juice in the mass on the wax paper.
Use a few paper towels, and press gently on the casein. The liquid will spill out like squeezing a sponge. Be careful not to make it too dry, because it will become difficult to mold if it's too dry.
Use a few paper towels, and press gently on the casein. The liquid will spill out like squeezing a sponge. Be careful not to make it too dry, because it will become difficult to mold if it's too dry.
Step 5: Mold!
At this point, you're ready to do whatever you want with the plastic.
It will take about two days to cure, but if you're using a mold where it cannot easily breathe, it will take longer.
One thing to watch out for is that the casein will warp when it's drying, especially if you have it rolled out into a sheet. It's best to put a weight on it. Watch out, though, because it will seep a milky-vinegary scented liquid into whatever is holding it in place. I used a heavy programming book...and it now has a funny smell to it. Awesome.
For my project, I just need to roll the casein out and let it dry.
Lay another sheet of wax paper over the casein. Use a rolling pin to spread it out. If you didn't dry it too much in the previous step, it should roll nicely, without many cracks or chunks.
Finally, I pressed it between two sheets of aluminum foil, and curved it across the bevel I'm using.
Give it a few days to dry, and it'll be ready to go. This is critical. Depending on how you wrap/mold your casein, you may find it takes more than a week to dry. Wrapping mine in foil took two weeks to get remotely dry. As is expected, the thicker it is, the longer it will take to dry.
I should also note that if you're making a flat piece like I am, the plastic will curl if you remove it from its mold before its dry. I made this mistake with this project, and ended up with a piece that was unusable because it curled.
The final product is quite rigid when it's thick (1/8 inch or thicker), moderately pliable when it's a little thinner, and brittle if it's paper thin. It's also sandable and paintable.
Go forth and have homemade plasticy fun!
It will take about two days to cure, but if you're using a mold where it cannot easily breathe, it will take longer.
One thing to watch out for is that the casein will warp when it's drying, especially if you have it rolled out into a sheet. It's best to put a weight on it. Watch out, though, because it will seep a milky-vinegary scented liquid into whatever is holding it in place. I used a heavy programming book...and it now has a funny smell to it. Awesome.
For my project, I just need to roll the casein out and let it dry.
Lay another sheet of wax paper over the casein. Use a rolling pin to spread it out. If you didn't dry it too much in the previous step, it should roll nicely, without many cracks or chunks.
Finally, I pressed it between two sheets of aluminum foil, and curved it across the bevel I'm using.
Give it a few days to dry, and it'll be ready to go. This is critical. Depending on how you wrap/mold your casein, you may find it takes more than a week to dry. Wrapping mine in foil took two weeks to get remotely dry. As is expected, the thicker it is, the longer it will take to dry.
I should also note that if you're making a flat piece like I am, the plastic will curl if you remove it from its mold before its dry. I made this mistake with this project, and ended up with a piece that was unusable because it curled.
The final product is quite rigid when it's thick (1/8 inch or thicker), moderately pliable when it's a little thinner, and brittle if it's paper thin. It's also sandable and paintable.
Go forth and have homemade plasticy fun!
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1. Heat some skimmed milk (do not let it boil)
2. Add about 3 teaspoons of vinegar (an acid) to the milk and stir slowly until the milk
separates into curds (solid sticky bits) and whey (clear liquid)
3. Pour the curds and whey through a tea strainer or sieve to collect the curds
4. In a container, add a little bit of bicarbonate of soda or milk of magnesia (alkali)
5. You should now have a sticky white substance called casein (milk protein). This can
be used as a binder in paint – just add some pigment!
Any other chemistry suggestions would be welcome.
Imagine, an army of Cheese-weilding warriors!
http://www.instructables.com/id/Easy_Biodegradable_Plastic/
As for "making it stronger" (your note below), you could possibly add some fabric, of some sort to strengthen it.
far, far too brittle. is this true?
But what are the advantages of extracted plastic?????
Although it contains caesin, would it cause any harm if someone eats it??????
Please do reply as soon as possible......
Just dissolve the styrofoam (polystyrene?) in acetone to a thick goo, mold and leave to dry in a remote area as not to get her indoors all worked up about the acetone smell?
It can take days & days for it to dry on its own, and of course it gives off acetone fumes the whole time. There's no chemical reaction - the acetone just dissolves the styrene in the the mostly-air styrofoam (emphasis on "foam"!), and then gets trapped inside the drying skin of the finished plastic if it's thick, slowing down the drying.
It shrinks somewhat in the drying process, but never (IME) breaks. Also, it seems to change if left in the acetone for a long time, becoming resistant to shape change, so it's best to mold it immediately after dissolving the styrene.
My project is quite simple: I have a motorbike where you cannot really get any plastic parts for it anywhere for love or money, and I need new wingmirror shells.
So either you are very very very lottery jackpot winning lucky if you find a part on ebay, or you cast it yourself.... I was originally thinking about resin casting, but resin costs a fortune. Casein seemed a good idea but being organic , I'm not sure about resistance to mold and fungus, and styrene seems easy enough to make... even if it may be more fragile than standard ABS plastic, I'm not very worried. You just need a ton of styrofoam to get a handful of goo :)
The other alternatives, like Sugru cost too much to be cost effective, and low temperature thermoplastics could melt if being left in the sun too long, so this method could allow me to make my prototype mirrors !
Cheers,
Daniel
Don't forget that needles have specific sizes; hand rolling, or using a straw might not create a standard size.
But I think most knitting needles were made out of galalithe - and I'm not really sure I want to use formaldehyde. Hmmmmmmmmmm. On the other hand, casein needles might even break when I'm carefully sanding them down.
Another question, I'm sorry... ;-) Any idea on how to turn the casein into a spinnable fibre?
Actually this is exactly the same as making tofu, from soya bean curd.
Citric acid - in powder form is cheap - especially in bulk.
Don't know about the casein content of soya bean flour...
Might be an idea to use skim milk powder as the fat free casein might be a better product.
Just curious - not that chemically ofay myself, but one would think that modifying the protein with HEAT and or other chemicals may have been done... just looked up.
http://books.google.com.au/books?id=0g9QjxsbqmUC&pg=PA136&lpg=PA136&dq=casien+plastic+heat+chemical&source=web&ots=u7KLwl6eWg&sig=9V40234r-SgMztftGpwzPYDrQgI&hl=en&sa=X&oi=book_result&resnum=1&ct=result
http://209.85.173.132/search?q=cache:SLP_f4OuT7QJ:www.umanitoba.ca/outreach/crystal/resources%2520for%2520teachers/Polymerization%2520-%2520Christy%2520Boettcher%2520%26.doc+casien+plastic+heat+chemical&hl=en&ct=clnk&cd=3&gl=au
http://chestofbooks.com/home-improvement/repairs/painting/Paint-Making-Color-Grinding/Part-V-Casein-And-Cold-Water-Paints-Chapter-XXXI-Origin-A.html
http://www.plastics-china.com/Raw_Material.htm
Casein Formaldehyde (Lactoid, Erinoid, Galalith)
Invented at the turn of the century, manufacture was based on fat-free milk to which resin was added to form curds which, when suitably dried, processed and coloured, could be extruded into rods and made into sheets. The material was then hardened in a bath of formaldehyde from whence it was machined into the desired end use. The brilliant colours and patterns made casein a leading material for making products such as buttons, buckles, fountain pen, barrels and knitting needles.
http://museo.cannon.com/museo/inglese/eplasti.htm
# Casein formaldehyde
Casein formaldehyde is a plastic of natural protein origin made from organic substances such as milk, horn or vegetable products such as soy beans, wheat and the like. It was obtained in 1897 by Adolph Spitteler and W.Kirsche who started out with whey and formaldehyde and tested the action of an enzyme on them. The patent was registered in Baviera and then extended to the USA, Great Britain and Italy. It should be noted that with its commercial name, Galalith (Galalite in Italy and Erinoid in Great Britain) it sometimes looked like celluloid, sometimes ivory and sometimes artificial horn. The first factory to manufacture it was in Great Britain in 1913. In 1930 world-wide production had reached 10,000 tons. Casein formaldehyde was used to make buttons, pins, cigarette-cases, fountain pens, umbrella handles and radio cabinets.