PURPOSE: To decrease a volume of a packed material as much as possible for decreasing costs of transportation, storage, and processing of the material.

CONSTITUTION: Material 12 such as trash or refuse is packed in a container 10 by an opposed hydraulic packing cylinder 16 and a hydraulic ejecting cylinder 20. Each cylinder is controlled by hydraulic control valves 64 and 66, and the control valve 66 for controlling the ejecting cylinder is, in effect, operated by the control valve 64 for the packing cylinder. This is accomplished by sensing the pressure applied to the packing cylinder, and when this pressure reaches a predetermined level, a pilot damp valve 104 in the ejecting cylinder 20 is opened to allow a piston 42 in the ejecting cylinder to retreat. When the pilot pressure drops below a predetermined level, the pilot damp valve 104 closes, allowing the packing cylinder to exert additional packing force. In this way the piston in the ejecting cylinder inches back and the material is intermittently packed.