Z-filter media pack arrangement; and, methods
Z-filter media pack arrangements and methods for providing them are described. The preferred arrangements have a cured-in-place jacket around an outside of a coiled z-filter media combination. The preferred cured-in-place jacket is a mold-in-place overmold which includes, integral therein, a housing seal arrangement. Preferably a cured-in-place center core is used, most preferably one that has opposite concave ends with seal arrangements configured to seal a lead end portion of the coiled z-filter media combination.
1. An air filter cartridge comprising:
(a) a coiled media combination comprising a fluted sheet secured to a facing sheet and defining a set of inlet flutes and a set of outlet flutes; the coiled media combination defining:
(i) an outer side wall extending between first and second opposite flow ends;
(ii) a coil center; and,
(iii) a media combination lead end positioned inside of the coil within the coil center; and,
(b) a mold-in-place center core positioned within the coil center and comprising molded-in-place seal material in a center of the coiled media providing at least a portion of a lead end seal.
2. An air filter cartridge according to claim 1 wherein:
(a) the mold-in-place center core has opposite ends at least one of which has an axially, outwardly, projecting end skirt to seal a portion of the lead end.
3. An air filter cartridge according to claim 1 wherein:
(a) the molded-in-place center core is formed from a resin that increases in volume during core.
4. An air filter cartridge according to claim 1 wherein:
(a) the molded-in-place center core is formed from a resin that increases in volume by at least 20% during cure.
5. An air filter cartridge according to claim 1 wherein:
(a) the molded-in-place center core is formed from a resin that increases in volume by at least 40% during cure.
6. An air filter cartridge according to claim 1 wherein:
(a) the molded-in-place center core is formed from a resin that increases in volume by at least 50% during cure.
7. An air filter cartridge according to claim 1 wherein:
(a) the molded-in-place center core comprises a foamed polyurethane core formed from a resin that increases in volume by at least 20% during core.
8. An air filter cartridge according to claim 1 wherein:
(a) the core has a density of no greater than 0.24 g/cc.
9. An air filter cartridge according to claim 1 wherein:
(a) the coiled media combination has a circular perimeter shape.
10. An air filter cartridge according to claim 1 wherein:
(a) the coiled media combination has an oval perimeter shape with opposite curved ends.
11. An air filter cartridge according to claim 1 wherein:
(a) the media pack has first and second, opposite, flow ends; and,
(b) a mold-in-place housing seal arrangement is positioned secured to the media pack in a manner extending around the media pack.
12. An air filter cartridge according to claim 11 wherein:
(a) a mold-in-place seal positioned on an outside of the media pack in extension between the first and second, opposite, flow ends.
13. An air filter cartridge according to claim 11 wherein:
(a) the mold-in-place housing seal arrangement is a foamed polyurethane mold-in-place housing seal arrangement.
14. An air filter cartridge according to claim 11 wherein:
(a) the mold-in-place housing seal arrangement has an as-molded density of no greater than 0.35 g/cc.
15. An air filter cartridge according to claim 11 wherein:
(a) the housing seal arrangement comprises an axial pinch seal.
16. An air filter cartridge according to claim 15 wherein:
(a) the axial pinch seal has opposite housing engagement surfaces spaced at least 4 mm apart.
17. A method of forming an air filter cartridge; the method comprising:
(a) coiling a strip of fluted media secured to facing media to define a media combination comprising:
(i) a outer sidewall extending between first and second opposite flow ends;
(ii) inlet and outlet flutes;
(iii) a coil center; and,
(iv) a media combination lead end positioned in the coil center; and,
(b) molding a molded-in-place center core within the coil center to provide at least a portion of a lead end seal and also a center plug in the coil center;
(i) the step of molding comprising positioning a resin in the coil center that increases in volume by at least 20% during cure.
18. A method according to claim 17 wherein:
(a) the step of molding comprises positioning a resin in the coil center which increases in volume by at least 40% during cure.
19. A method according to claim 17 wherein:
(a) the step of molding comprises positioning a resin in the coil center which increases in volume by at least 50% during cure.
20. A method according to claim 17 wherein:
(a) the step of molding comprises molding a center core from foamed polyurethane.