Apparatus and method for regulating filter media pack pleat spacing

1. A cartridge filter with self-regulated pleat spacing, comprising:

a cylindrical pleated filter media having a plurality of pleats;

said plurality of pleats extending in a longitudinal direction, said pleats arranged side by side in a transverse direction, said plurality of pleats having a series of alternating pleat tips and pleat valleys in said transverse direction;

a cylindrical inner screen;

said pleated filter media having an inner filter surface and an outer filter surface, said inner filter surface adjacent said inner screen;

at least one first adhesive bead applied to said inner filter surface, said first adhesive bead traversing a plurality of said pleat tips and said pleat valleys;

at least one second adhesive bead applied to said outer filter surface, said at least one second adhesive bead at least partially encircling said pleated filter media; and

said at least one second adhesive bead having greater elasticity than said at least one first adhesive bead, said at least one second adhesive bead maintaining pleat spacing of said outer surface when said cylindrical pleated filter media is transformed from a planar form to said cylindrical pleated filter media.

2. The cartridge filter of claim 1 wherein said pleated filter media further comprises a plurality of filtration layers.

3. The cartridge filter of claim 2 wherein at least one of said plurality of filtration layers is a porous membrane layer.

4. The cartridge filter of claim 2 wherein at least one of said plurality of filtration layers is a non-woven particulate retention layer.

5. The cartridge filter of claim 1 further comprising a cylindrical outer screen adjacent said outer filter surface.

6. The cartridge filter of claim 5 further comprising a pair of end caps disposed on opposite ends of said cartridge filter.

7. The cartridge filter of claim 1 further comprising a pair of end caps disposed on opposite ends of said cartridge filter.

8. The cartridge filter of claim 1 wherein said at least one second adhesive bead includes at least one additional second adhesive bead, wherein said at least one second adhesive bead and said at least one additional second adhesive bead are substantially parallel and spaced apart from each other.

9. The cartridge filter of claim 1 wherein at least one adhesive bead of said at least one first adhesive bead and said at least one second adhesive bead is continuous.

10. A cartridge filter with self-regulated pleat spacing, comprising:

a tubular pleated filter media having a longitudinal axis and a plurality of pleats;

said plurality of pleats extending longitudinally approximately parallel to said longitudinal axis, said plurality of pleats having a series of alternating tips and valleys arranged transverse to said longitudinal axis;

a tubular inner screen;

said pleated filter media having an inner filter surface and an outer filter surface, said inner filter surface adjacent said tubular inner screen, said outer filter surface forming an outer circumference of said pleated filter media;

at least one first adhesive bead applied to said inner filter surface, said first adhesive bead extending in a direction transverse to said longitudinal axis;

at least one second adhesive bead applied to said outer filter surface, said second adhesive bead at least partially encircling said tubular pleated filter media in a spiral form; and

said at least one second adhesive bead having greater elasticity than said at least one first adhesive bead, said second adhesive bead inhibiting breaching of said plurality of pleats on said outer surface when said tubular pleated filter media is transformed from a planar form to said tubular pleated filter media.

11. The cartridge filter of claim 10 wherein said tubular pleated filter media further comprises a plurality of filtration layers.

12. The cartridge filter of claim 11 wherein at least one of said plurality of filtration layers is a porous membrane layer.

13. The cartridge filter of claim 11 wherein at least one of said plurality of filtration layers is a non-woven particulate retention layer.

14. The cartridge filter of claim 10 further comprising a tubular outer screen adjacent said outer filter surface.

15. The cartridge filter of claim 14 further comprising a pair of end caps disposed on said longitudinal axis on opposite ends of said cartridge filter.

16. The cartridge filter of claim 10 further comprising a pair of end caps disposed on said longitudinal axis on opposite ends of said cartridge filter.

17. The cartridge filter of claim 10 wherein said at least one second adhesive bead includes at least one additional second adhesive bead, wherein said at least one second adhesive bead and said at least one additional second adhesive bead are substantially parallel and spaced apart from each other.

18. The cartridge filter of claim 10 wherein at least one adhesive bead of said at least one first adhesive bead and said at least one second adhesive bead is continuous.

19. A method of constructing a cartridge filter with self-regulated pleat spacing, comprising the steps of:

forming a planar filter media;

pleating said planar filter media;

applying a first adhesive bead to a first surface of said planar filter media;

applying a second adhesive bead to a second surface of said planar filter media, said second surface opposite said first surface, wherein said second adhesive bead has greater elasticity than said first adhesive bead; and

transforming said planar filter media into a tubular shaped pleated filter media wherein said first surface of said planar filter media becomes an inner surface of said tubular shaped pleated filter media and said second surface of said planar filter media becomes an outer surface of said tubular shaped pleated filter media.

20. The method of claim 19 further comprising the step of attaching a first portion of said tubular shaped pleated filter media located at or near a first side of said tubular shaped pleated filter media to a second portion of said tubular shaped pleated filter media located at or near a second side of said tubular shaped pleated filter media.

21. The method of claim 19 further comprising the step of attaching said tubular shaped pleated filter media to an inner screen.

22. The method of claim 21 further comprising the step of attaching an outer screen adjacent said outer surface of said tubular shaped pleated filter media.

23. The method of claim 21 further comprising the step of attaching a pair of end caps to said inner screen.