Abstract: An arrangement for perforation a stripe of a ductile material such as plastics or a ductile metal such as aluminum or copper and for forming a lattice of the stripe comprises a preferably rotating cutting roll, which cooperates with a holding-up tool. The cutting roll has at least one axially aligned row of cutting plates. Each cutting plate has a cutting edge and a partly cylindrical part, which forms a part of the cylindrical mantle surface of the cutting roll. In cooperation with the holding-up tool the cutting edges of the cutting plates make a row of slots in the stripe, whereupon the walls of the slots are extended in the longitudinal direction of the stripe, while the partly cylindrical parts of the cutting plates hold other parts of the stripe against the holding-up tool so as to form a lattice without changing the width of the stripe.

Abstract: A centrifuge apparatus, primarily for use in the continuous or semi-continuous separation of blood, has a disposable separation unit which is orbited on a centrifuge rotor. The separation unit has a sealed jacket which is held against rotation during the orbiting and communicates with a stationary and nonrotatable liquid inlet and outlet connector on the rotor axis. A separation vessel rotatably mounted in the jacket communicates with liquid inlet and outlet passages in the jacket and is rotationally unbalanced to orient itself relative to the rotor during the orbiting of the jacket.