Abstract: A double-wall fuel container of plastic material is composed of at least two shell portions which are welded together. The half-shell portions are each in the form of double-wall blow moldings, with a gap being kept free at least in a region-wise manner between the walls of the blow moldings.

Abstract: A mold system has a pair of mold halves movable toward and away from each other, a threaded spindle coupled to one of the mold halves, and a nut threaded on the spindle and coupled to the other of the mold halves. A high-speed low-torque brakable spindle motor is connected to the spindle and operable to rotate the spindle in the nut and a low-speed high-torque nut motor separate from the spindle motor is connected to the nut and operable to rotate the nut on the spindle. In a first mold-closing stage the spindle motor is operated to rotate the spindle in the nut and move the mold-halves rapidly toward each other. Thereafter in a second and subsequent mold-clamping stage the spindle motor is braked and the nut motor is operated to rotate the nut on the spindle and press the mold halves against each other.