The ornamental design for a materialhopper, as shown and described.
FIG. 1 is a perspective view of a material hopper showing our new design;
FIG. 2 is a left side view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a back view thereof;
FIG. 5 is a front view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a section view taken through the section line in FIG. 1; and,
FIG. 9 is a section view taken through the section line in FIG. 1.
The broken lines shown in the drawings are included for purposes of illustrating portions of the material hopper and form no part of the claimed design.