Micro-burrs in machining original molds of an optical functional film with a triangular pyramidal texture

Abstract

Abstract During the cutting process of the original molds, the micro-burrs produced by the machining process will affect the optical properties of the optical functional textured film. According to the forming planing method for the triangular pyramid texture, the formation characteristics of burrs are analyzed from the cut-in edge and the cut-out edge. And the influence of burrs on the triangular pyramid edge is analyzed in combination with the changes of cutting section, to obtain the prediction model of edge burr distribution. The cutting simulation of triangular pyramid texture shows that the main flow direction of the chips will be inclined along the side where the cutting edge is separated from the workpiece first, resulting in a larger exit burr size on this side. In the cut-out stage, as the contact length between the cutting edge of the tool and the workpiece decreases gradually, the maximum cutting stress gradually transfers to the tool tip so that the positive burrs form at the bottom of the cut-out edges of the triangular pyramid. The forming processing experiment for the triangular pyramid texture shows that there are both positive and negative exit burrs on the cut-out edges. Compared with the forming processing method, the V-shaped section of the cutting layer is changed to the trapezoidal section of the free chips when the original molds with triangular pyramid texture are cut by the single-edge cutting method. As the chips flow more smoothly, the size of burrs can be reduced. Besides, the ratio of the effective optical functional area K s can increase 10.1%.