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!
Remove these ads by
Signing UpStep 1Ingredients & Utensils
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).
| « Previous Step | Download PDFView All Steps | Next Step » |















































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.
"The curds are neutralized with a base, such as sodium bicarbonate (baking soda), to cause them to unclump and become a thicker plastic-like substance."
Could be a useful additional step.
http://en.wikipedia.org/wiki/Galalith (if that's what this is) suggests this is a thermoset plastic. So it won't melt.