A three-dimensional object printing system improves the interlayer adhesion of an object. The printing system includes a platform on which a three-dimensional object is built. A material applicator in the printing system expels material to form layers of the object on the platform. The material applicator also includes a heater configured to heat the layer of the object ahead of the material applicator when the material applicator moves in a first direction and a second direction, both directions being parallel to the platform.