Food processing blades may need sharpening after prolonged use. The best way to get the job done is to sharpen the blades manually. Electric sharpeners and grinders can strip away metal and weaken the blades, making them potentially dangerous to use in your food processor. Instead, buy a sharpening stone or file designed for this space and sharpen your blades.
Hold the food processor blade firmly by the plastic spindle, taking care to keep your fingers clear of the metal. Grasp the sharpening file with your free hand, holding it so your fingers curve underneath the file and your thumb rests on top. This grip gives good control over the sharpening file.
Hold the file over the blade edge and move it away from you in one continuous sawing motion so that at the end of the sharpening movement the file tip is on the farthest edge of the blade. Use firm but not hard pressure as you move the sharpening file or stone across the blade edge. Repeat 4 to 5 times.
Turn the blade over in your hand and grasp firmly. Sharpen the blade by moving the file with the same sawing motion but toward you this time. Rinse the food processor blade and allow to air dry.