If you made a list of packaging types where you are most likely to see the most interesting ideas, I would wager casings would be nowhere near the top. After all, casings are casings, be they collagen, natural, fibrous or whatever. Well, rub your eyes and blink.
Casings are now being coextruded in-line, simultaneously, formed continuously around pumped meat product like fresh sausage. The casings are made from alginate, which is derived from seaweed, processed into a powder and mixed with water to make an aqueous gel or paste. Concurrent to forming the casings, they are treated with calcium chloride. This imparts strength, the proper balance of rigidity and flexibility, and thermal stability.