Injection moulding machines are used for the production of parts in large quantities from thermoplastic materials. The injection units of such machines draws the plastic into the heated plastifying unit by means of a screw feed. The screw feed moves back in a linear direction from the tool. This is the metering stage.

In the injection stage, the plastifying unit moves rapidly toward the tool and presses the plastic into the mould. Both the rotation of the screw feed and the linear movement of the injection unit are hydraulically driven. The screw feed is arranged beneath the central axis. The linear bearings must be insensitive to heat and vibration and must also have high basic static and dynamic load ratings.