US Patent 7600308 Method for making a drainage element

Drainage elements are made by delivering loose fill elements under gravity from a container into a sleeve of netting that is tied at one end to a pipe, or other endless element, that is passing through the container. The sleeve of netting is supplied from an apertured cage extending below the container. In one embodiment a blower and chute arrangement is used to blow air downwardly into the drainage element being formed to increase the rate of flow of the loose fill elements into the sleeve of netting.