Thick Lunac 2+ coatings applied to screws
Extrusion and plasticizing screws that are exposed to plastics containing vast amounts of abrasives such as glass fibres, should at least be hardened or nitrided. In some cases (partially) full ceramic screws are obtainable. Lunac 2+ now opens the possibility to practically turn a current steel screw into such a full ceramic screw, yet preserving the characteristic steel toughness. Another important feature is the, for a hard coating almost unparalleled, good throwing power in the deep structures (usually 6 times better than that of hard chromium). Thick closed coatings can be deposited all the way down to the deep corners (>100 µm (0.004")). Three other significant improvements are that these wear resistant screws have good resistance to corrosion as well as the coating will stay closed under a heavy load and the tendency that plastic sticking will be reduced.
An extrusion screw can perform well over a long term due to the good corrosion and wear resistance of Lunac 2+ in a glass fibre filled PVC environment. The very good throwing power of this coating in deep structures is typical for Lunac (>100 µm (0.004") in the deep structures vs. 130 µm (0.005") near the flight tips). Although less explicit than with Lunac 1, Lunac 2+ offers a non stick effect.
