| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily regulate film thickness and surface roughness by spraying water droplets regulated in particle size, spray pressure and spray quantity on an extrusion molded resin sheet during a period when the temp. of the sheet from a die is its softening point or higher. SOLUTION: An extruder 10 has an extrusion die 11 and a raw material charging hopper 12 and a pair of chill rolls 14, a plurality of stretching roll groups 16, a film thickness meter 17 and a taking-up roll 18 are provided on the downstream side of the die 11. A plurality of waterdrop nozzles 20 are arranged in the lateral direction of a sheet. Waterdrops are applied to the sheet during a period when the temp. of the sheet is yet the softening point of the sheet immediately after extrusion to regulate film thickness. The particle size of sprayed waterdrops is set to 1-150μm in order to accurately control quenching effect, film thickness and surface roughness. Spray pressure is set to 0.1-10kgf/cm<2> in order to eliminate the deformation of a film and spray quantity (spray density) is set to 0.01-1l/hr/cm<2> so that film thickness and surface roughness can be regulated by quenching effect and water quantity.</p> |
