A Cream Separator is device invented by Martin Wiberg to separate cream from milk (see also Gustaf de Laval). Before milk-cream separators, cream was separated from milk by letting milk sit until the fat floated to the top and could then be skimmed off by hand.
The separator was first made by Gustaf de Laval in 1877. With it, it was possible to separate the cream from the milk. When it spins, the milk, which is heaviest, is pushed outward against the walls and the cream, which is lighter, is collected in the middle.
Gustaf de Laval's construction made it possible to start the largest separator factory in the world, Alfa Laval AB. The milk-separator became a big advance in industry in Sweden. Within the first decade in the 1900s there were over twenty separator manufacturers in Stockholm. Separators (albeit slightly modified)are also used on ships to purify oil.