Filter for oil containing adhesive contaminants

A filter element assembly useful for removing particulate matter and undissolved adhesive material from a filterable liquid, the assembly comprising separate particulate and adhesive removing filters and a foraminous flow spacer disposed between them, the particulate removing filter comprising an elongate first body of first filter medium defined for flow of liquid axially therethrough from an inlet end to an outlet end, the body of first filter medium having an exterior surface extending between the said ends, the adhesive removing filter comprising a second body of different filter medium disposed proximately adjacent the inlet end and at least a portion of the first body's exterior surface which extends from that body's inlet end toward its outlet end, the spacer being present between the first and second filter media across the inlet end of the first body and over at least said portion of the exterior surface of the first body, the spacer affording flow of liquid emergent from the second body directly to the first body's inlet end and along said portion of the first body's exterior surface to its inlet end.

A method for removing particulate matter and undissolved adhesive from a filterable liquid comprising:

• providing an axial flow filter defined to remove particulate matter from the liquid, the axial flow filter having length between opposite inlet and outlet ends,
• providing, around the axial flow filter along at least a portion of its length and across its inlet end, an adhesive-removing filter medium defined for liquid flow through it in a direction transverse to the lateral extent thereof, separating the adhesive-removing filter medium and the axial flow filter, along said filter and across its inlet end, by a spacer structure which affords liquid flow through it and laterally along its extent, and
• flowing adhesive-contaminated liquid first through the adhesive removing filter into the spacer structure, through and along the spacer structure to the inlet end of the axial flow filter, and through the axial flow filter.

A method for removing undissolved adhesive and particulate matter from a filterable liquid, comprising:

• flowing the liquid through a first filter medium having a relatively large inlet flow area, the first medium being useful to remove the adhesive from the liquid, and introducing liquid emergent from the first medium into a second filter medium having a relatively small inlet area, the second medium being useful to remove finely divided particulate matter from the liquid, arranging the second filter medium as an axial flow filter having length between opposite inlet and outlet ends,
• disposing the first medium around the exterior and across the inlet end of the axial flow filter, and
• separating the first medium and the axial flow filter by a spacer structure which affords flow through it and laterally along its extent.