MANUFACTURE OF SHEET WITH RECESSION AND PROTRUSION IN ITS SURFACE

摘要

PURPOSE:To manufacture the titled sheet correctly in a predetermined shape by providing a co-extrusion metal mouth niece containing a main passageway and an auxiliary passageway. CONSTITUTION:In the case of employing light transmission resin and light non-transmission resin as first resin, extrusion molding machines 1, 2, 3 are comprised of a first extruding machine 1 for light transmission resin, a second extruding machine 2 for light non-transmission resin, and a third extruding machine 3 for resin having incompatibility with the first resin. The resin melted by each extruding machine is passed through fixing pumps 4,5,6 and passageways 9,10,11, thereby forming the layer of a base material with recessions and protrusions in its surface that becomes a main passageway from a first nozzle 12. Next, light non-transmission resin B is supplied to a second nozzle 13, and on a predetermined place of the recession and protrusion parts formed on light transmission resin A, a light insulating layer or a out-light absorbing layer is formed. Furthermore, by resin C having incompatibility with the first resin supplied by the third nozzle 14, the recession and protrusion surface is covered. In the next place, the resin A, resin B, and resin C are co-extruded simultaneously from a discharging nozzle 15 and made into a three-layered sheet. Thereafter, the resin C is separation-removed therefrom by a separating device 16.