The ornamental design for a cartridge for an airtreatment appliance, substantially as shown and described.
FIG. 1 is a top isometric view of a cartridge for an air treatment appliance.
FIG. 2 is a bottom isometric view thereof.
FIG. 3 is a front elevational view thereof.
FIG. 4 is a rear elevational view thereof.
FIG. 5 is a left side elevational view thereof.
FIG. 6 is a right side elevational view thereof.
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
Stippling and tangency lines in the drawings represent the three-dimensional contours of the design, and are not intended to indicate surface decoration. The broken lines showing portions of the cartridge for an air treatment appliance are included for the purpose of illustrating portions of the article and form no part of the claimed design.