摘要 |
Production of extruded articles, using thermoplastic polymers as starting material. The method uses mono-thread extruder composed of at least three successive functional zones: (a) feeding or entry zone; (b) central compression or melting zone; and (c) pumping or exit zone, and connected to die with the adapter. Homogeneous mixture, prepared at ambient temperature, and fed to entry zone of extruder, comprises at least two (preferably least three) thermoplastic polymer-based components of different color, with at least part of one or both being in granulated fo If needed, the components may contains one or more additives such as agents improving impact strength of extruded objects. The temperature of entry zone (a) is maintained at a level below the melting point of thermoplastic polymers used, that of central z (b) is kept at a level below (by at most 25 degrees C) or equal to that of melting point of polymers, and that of exit zone (c) level higher than that of melting point (by at most 25 degrees C in major part of zone and by 10-30 degrees C at the final part close to exit); while the time of residence of the mixture within the extruder adjusted in such way as to produce molten mixed heterogeneous stream at the exit from extruder, which is then divided into at least two streams fed to die through the adapter. An Independent claim is also included for the thermoplastic extruded articles having colored vein effect on their surface a within, obtained using process as claimed from materials as described, having cellular homogeneous distribution, density 0.6-1.5 and capability to be shaped and thermo-shaped. |