Old cardboard vacuums-the material isn't really cardboard-but like Masonite(hardboard)-a harder,tougher material intended to be a building material.It can be bent into a cylindrical form easily-thus a vacuum cleaner body.Manufactuers then thought metals and plastics would be better materials for a vacuum cleaner body.Masonite type materials can be weakened if they get wet-even tempered grade.
Yes many modern vacuum cleaners--cheap plastic ones esp-and bagless-fill 'em up-toss 'em into the dumpster.The idea of the carboard vacuum is indeed unusual-cardboard body parts easily replaced.Bet this will have to be done often during the life of that machine.We all know the tough,rough life vacuum cleaners have to endure.for the old "cardboard"? or hardboard vacuums as above-remember plastics weren't available then-and the means to use them.
