Device for compacting powder material, in particular ceramic material

A device for compacting a layer of powder material comprising ceramic powder, the device comprising:

• a movable surface, which is configured to substantially move together with the layer of powder material in a predefined feeding direction;
• a compacting belt, which is provided with a compacting surface facing the movable surface and is substantially movable in the feeding direction;
• a pressing device, which is configured to press the compacting surface towards the movable surface, so as to press the layer of powder material interposed between them;
• and
• an expansion countering device, which is configured to act upon the compacting belt, so as to partially counter expansion of the layer of powder material downstream of said pressing device;
• wherein the expansion countering device comprises a pushing unit, which is configured to release a gas under pressure, so as to create a pushing gas cushion on said compacting belt in order to exert, upon said compacting belt, a compression action that partially counters the expansion of the layer of powder material downstream of the pressing device,
• wherein the pressing device is configured to exert a first pressure on the layer of powder material at least ten times greater than a second pressure exerted on the layer of powder material by the pushing unit;
• the pushing gas cushion being created where the device is configured to let the layer of powder material expand;
• wherein the pushing unit comprises at least one pusher, which is supplied with the gas under pressure, so that said at least one pusher is separated relative to said compacting belt by means of said pushing gas cushion;
• wherein the compacting surface is arranged between the at least one pusher and the movable surface;
• wherein said pushing unit further comprises at least one sensor, which is designed to detect speed and pressure of the gas located in said pushing gas cushion and one or more physical parameters of the gas flowing out of said pushing gas cushion into an external environment;
• wherein said at least one sensor is designed to detect a flow rate of the gas flowing out of said pushing gas cushion into the external environment;
• wherein said expansion countering device further comprises:
• an electronic control unit;
• a hydraulic operating unit configured for allowing variation of a distance of the pushing unit with respect to the compacting surface;
• and
• a pneumatic operating unit configured for supplying the gas under pressure to the at least one pusher, the pneumatic operating unit comprising a compressor and a gas supply duct by means of which the gas under pressure is supplied into a recess of the at least one pusher;
• wherein the hydraulic operating unit and the pneumatic operating unit are connected to the electronic control unit;
• and
• wherein the electronic control unit is programmed to control operating parameters of the hydraulic operating unit and the pneumatic operating unit such that i) said at least one pusher exerts, upon said compacting belt, said compression action that partially counters the expansion of the layer of powder material downstream of the pressing device in a controlled manner, ii) said at least one pusher is separated relative to said compacting belt by means of said pushing gas cushion, iii) said pushing unit exerts on the layer of powder material the second pressure to control the expansion of the layer of powder material downstream of the pressing device, and iv) said gas flowing out of said pushing gas cushion into the external environment avoids direct contact between a peripheral projecting edge of the at least one pusher and the compacting belt. direction.