| 摘要 |
PURPOSE:To obtain a molding for program tape check or a model mold having good scraping property, no brittleness and excellent melt-adhesive property, by using a mixture of a specified polyethylene and a specified paraffin wax. CONSTITUTION:A mixture of 20 to 80wt% of low density polyethylene A, whose intrinsic viscosity [eta] is 0.6 to 1.2dl/g and density 90 to 93, respectively, and 80 to 20wt% of paraffin wax, whose MW is 350 to 2,000 and m.p. is 55 deg.C to 105 deg.C, respectively, is poured into a mold being under reduced pressure after melt-blending. The molten mixture extruded from an extruder 1 passes through a connecting part 2 and is poured into a mold 4 from a pouring nozzle 3. A hole 8 located on the end of a cover 6 is connected with a vacuum pump 9, which reduces the pressure of the whole mold. The temp. of the molten mixture can be selected in a wide temp. range of 1,500 deg.C to 280 deg.C, but it is preferable to be as low as possible taking into account the molding cycle and the deterioration of the resin. |
