ANTISTATIC AND ELECTROCONDUCTIVE PLASTIC MATERIALS

Today we tell you how we solved, for our client in Eastern Europe, an aesthetic and technical quality problem on an American CoExtruder composed of a Single Screw Extruder 75-36 LD and a Single Screw Extruder 60-33 LD.

The production of sheets in HIPS material first of all presented a challenge in terms of maintaining quality when changing thickness. From a minimum of 0.7mm to a maximum of 2.2mm and the need to maintain not only an optimal aesthetic appearance but also an electrical conductive capacity. The material fed was and still is composed of very viscous 70% HIPS regenerated granules + a 30% carbon black filler

Problems to solve:
• Bubbles and smoke streaks
• Poor plate electrical conduction

Plus desired but not imperative:
• Increase poor output due to high viscosity of the material

Solution:
After analysing the parameters and the production cycle, we completely modified the feeding area and the cooling system, made consequent changes to the screw profile for a correct match to the new feeding structure and updated the technical peculiarities (zones, compression ratio, change of the tapers of the cores) of a single helix screw changed the outgassing on both the screw and the barrel.

What we reached:
• Total elimination of streaks and smoke effect
• Disappearance of bubbles
• Total conformity of the sheets both in terms of aesthetics and electrical conduction required regardless of their thickness.
• Output improvement of +10% on average across the various thicknesses