The ribbon blender mixes of dry granules and powders homogeneously materials within a U- shaped trough. A horizontal agitator consisting of precisely pitched inner and outer helical ribbons moves materials in a well-balanced axial and radial flow pattern. High-quality ribbon blenders feature tightly controlled clearances between the trough surfaces and agitator tips. Good design and expert fabrication ensure fast repeatable mixing, easy clean-up, low maintenance, and long service life.