Skim Milk Products (Apr, 1951)
At one time skim milk was used only by dieting females. But now government research labs have found other uses for the casein fiber derived from it. See above: 1, 3 and 7, brushes; 2 and 6, straight fiber; 4, curled fiber used in carburetor air filters; 5. stiff cloth produced from bristle fiber.
Do they still use milk for these things? Is that why milk is so darn expensive?
Yes the still derive caseins from milk for plastics, adhesives, and paints.
http://www.plastiquaria…
http://www.nationalcase…
http://www.jerrysartara…
But it is not what makes milk expensive as they are using the stuff that is removed to make skim milk.