GNP60 - GNP80

The GNP60 - GNP80 are the new series of linear calibrating polishing machines, designed to match the high quality standard of the distinctively thin and large-sized product MS-cementoceramica. An answer to the demand for total quality: a machine of high versatility and profitability but easy and safe to operate. Equipped with the new TEC electronic control of the thickness, which allows the operator to simply set the value of the required thickness and leave the machine work to get it. The two series are only diversified by the useful widht of the conveyor belt, 700 mmm and 830 mm respectively, while are completely similar in all other characteristics. The machine composes of a single-piece, network-structure basement on which are placed the beam supporting the stationary calibrating-grinding heads and the runways of the mobile bridge holding the polishing heads. The machine can be equipped with 3 to 5 stationary heads and with 10 to 14 heads on the mobile bridge. The multiplayer conveyor belt is driven by an inverter-fed epicyclical motoreducer for a continuous variation of its speed and for a smooth progress of the processed material. The feed speed of the bel can be read on a digital display. The tiles are kept in place by side-guides (and by a central one in case of two rows) made of polyzene-coated steel for reduced friction. The distance of these guides is adjustable with high precision by a mechanism operated from a single position. Doors and hatches made of inox-steel and provided with safety locking devices preventing opening until all heads are stopped. Bolts and screws made of inox-steel or brass. Switch and control board provided with PLS for a continuous and precise control of the working pressure and of the thickness of the tiles.

The STATIONARY HEADS, of large dimensions, perform the grindind and the calibration necessary to reach the rewuired thickness, using grindind wheels diam.750 or 880 mm, diamond discs, Frankfurt of Fickert segments. The TEC system controls the thickness of the tiles out of each grindind-calibrating head and automatically adjusts the working pressure until the required final thickness is reached. The head casings are made of cast iron and are fitted to a beam f high rigidity which allows precise and vibration-free grinding and calibrating operations. The up and down drive of the spindle can be electromechenic through a screw-nut screw system in oil bath and inverter-fed motor or hydraulic by means of a cylinder assisted by and hydraulic unit. These heads are available in two different versions, On Customer's demand, one with fixed casing and mobile spindle-abrasive holding plate assembly and the second one with casing and integral spindle and plate sliding on special rectified guides. In both versions the motor-spindle connection is made by means of belts and pulleys, in oder to reduce vibrations and cimplify the variation of speed required by different abrasive tools like carborundum wheels, Frankfurt of Fickert segments, diamond discs. Each single head casing is provided with start-stop switches and with the controls for the adjustment of the tiles thickness.

The POLISHING HEADS, fitted on the mobile bridge, carry out the fine polishing of the tiles using Frankfurt segments. Each head is pneumatically operated by means of two lateral cyliders. The working pressure is adjustable independently on each head and compensated by a plenum chamber.
The beam holding the polishing heads is a single-piece, sturdy structure designed to avoid vibrations. The transversal movement of the beam, adjustable in speed, is guided by two prismatic guides, rectified and protected. The beam is driven, in its to and fro didplacement, by a connecting rod - crank system, centrally located, which conerts rotating motion into armonic movement avoiding noxious swuingings of the beam. This system is also slack-free and gurantees rigidity and reduced friction, Thus improving the quality of finishing of the processed product. The lenght of the stoke of the beam is adjustable according to the size of the tiles to be processed. Each head is provided with an easy readble synoptic panel, with start-stop switches, pressure adjusting knobs and control of the wear og the abrasives; when the abrasives are worn out the head is automatically lifted, the motor is stopped and a ligh flashes. For the changing of the abrasive, the beam automatically stops at the operator side of the machine. The abrasive-holding plate has a diametre of 470 mm on the GNP60 model and a diametre of 550 mm on the GNP80 model and is fitted to the spindle through an elastic connection for a perfecr matching to the surface of the tiles.