Abstract: A process for treating polymer granular material (2) comprising the steps of heating and drying the polymer granular material in a drying hopper (10) by means of a drying gas, discharging a portion of the polymer granular material into an extruder (101), inside which the polymer granular material is brought to a molten or semi-molten state and transported along the extruder by a rotating screw (104) in order to be injected into a mould (102) or caused to pass through an extrusion head. The process provides for measuring a control parameter which is correlated with the rotation of the screw inside the extruder and regulating the flow rate of the drying gas on the basis of the control parameter.

Abstract: An installation for crystallizing and drying granular polymer material with a low level of crystallinity includes: a crystallization hopper, in which the granular polymer material is maintained in an agitated state and is processed with a first gas flow which is heated to a first temperature; a heating hopper which is arranged downstream of the crystallization hopper and in which the crystallized granular polymer material is heated to a second temperature which is greater than the first temperature, a drying hopper which is arranged downstream of the heating hopper and in which a predefined level of pressure reduction is maintained to dry the granular polymer material, and a supply hopper which is arranged downstream of the drying hopper and which is provided to supply a transformation machine with the granular polymer material.

Abstract: A drying installation for granular polymer material includes a hopper, in which the granular polymer material is dried, and a supply circuit for a process gas which is provided to dry the granular polymer material. The drying installation also includes a turbofan which is able to rotate an impeller of the turbofan at a speed of at least 7000 rpm and which is provided to move the process gas along the supply circuit towards the hopper.

Abstract: A gravimetric metering device which is provided to add an additive material to a polymer material includes a hopper which to contain the additive material and a supply member which is provided downstream of the hopper in order to receive the additive material which is discharged from the hopper and to transport it towards a discharge opening which is connected to the polymer material, and a first and second weighing element which are provided to detect the weight of the additive material which is discharged from the gravimetric metering device. The first weighing element is configured to detect a weight within a first maximum weighing range while the second weighing element is configured to detect a weight within a second maximum weighing range different from the first maximum weighing range.

Abstract: A gravimetric metering device which is provided to add an additive material to a polymer material, includes: a hopper to contain the additive material, a supply member to transport the additive material discharged from the hopper towards the polymer material, and first and a second weighing elements to detect the weight of the additive material discharged from the gravimetric metering device. A control unit determines, on the basis of the weight detected by the first weighing element, the flow rate of additive material discharged from the gravimetric metering device by regulating the supply member and controls the operation of the first weighing element by means of the second weighing element by comparing, at the start and at the end of a cycle for charging the hopper with the additive material, the weight detected by the first weighing element with the weight detected by the second weighing element.

Abstract: A drying plant (1) for granular polymer material based on polyethylene terephthalate (PET) comprises a hopper (2), which the granular polymer material is dried and a supply and recirculation circuit (10) for a process gas which is provided to dry the granular polymer material and comprising a catalysing group (25) which is configured to promote a decomposition reaction of contaminating substances which are present in the process gas and which are released from the granular polymer material in the hopper.

Abstract: A plant for drying granular polymer material comprises a hopper, in which granular polymer material is dried, and a process gas circuit which is configured to supply a process gas to the hopper in order to dry the granular polymer material.

Abstract: A process for drying granular polymeric material, comprising the steps of: dehumidifying the granular polymeric material by means of a first flow of gas at a first temperature of between 100° C. and 150° C.; heating the dehumidified granular polymeric material to a second temperature, greater than the first temperature; drying the granular polymeric material heated to the second temperature, by applying a predefined vacuum level; and transferring the dried granular polymeric material to a feed hopper (40) provided upstream of a working machine (100).

Abstract: A process for drying granular polymeric material, includes: dehumidifying the granular polymeric material by a first flow of gas at a first temperature of between 100° C. and 150° C.; heating the dehumidified granular polymeric material to a second temperature, greater than the first temperature; drying the granular polymeric material heated to the second temperature, by applying a predefined vacuum level. The pressure-sealing elements include a filling unit, which includes a small tank blocked upstream and downstream by shut-off valves, as well as a discharge unit, which includes a small tank blocked upstream and downstream by respective shut-off valves.

Abstract: A process for drying polymeric granular material (2) comprises the steps of: —introducing into said drying hopper (10) a process gas having a predefined flow rate so as to heat and dry the polymeric granular material, —discharging a portion of the heated polymeric granular material into a transformation unit (100) for the polymeric material; —loading an amount of fresh polymeric granular material (2a) into the drying hopper. The process gas flow rate is regulated by measuring the inlet temperature of the fresh polymeric granular material (2a) and comparing it with a predefined inlet temperature of the fresh polymeric granular material, on the basis of which the predefined process gas flow rate has been calculated. If the measured inlet temperature is different from the predefined inlet temperature, the flow rate of the process gas is regulated on the basis of the measured inlet temperature.

Abstract: A plastics material transformation plant (100) comprises a transformation machine (10) for the plastics material by means of moulding or extrusion, a feeding hopper (13) which is positioned upstream of the transformation machine and a metering device (1) which is arranged to add a liquid additive to the transformation machine. The metering device (1) comprises a container (4) in which the liquid additive is contained, a metering pump (5) which is connected to the container in order to take the liquid additive and to supply it to the transformation machine (10), and a thermo-regulation system of the liquid additive which is arranged to maintain the temperature of the liquid additive in a range of 2° C. more or 2° C. less than a predetermined temperature value.

Abstract: A process for treating polymer granular material (2) comprising the steps of heating and drying the polymer granular material in a drying hopper (10) by means of a drying gas, discharging a portion of the polymer granular material into an extruder (101), inside which the polymer granular material is brought to a molten or semi-molten state and transported along the extruder by a rotating screw (104) in order to be injected into a mould (102) or caused to pass through an extrusion head. The process provides for measuring a control parameter which is correlated with the rotation of the screw inside the extruder and regulating the flow rate of the drying gas on the basis of the control parameter.

Abstract: A process for drying granular polymeric material, comprising the steps of: dehumidifying the granular polymeric material by means of a first flow of gas at a first temperature of between 100° C. and 150° C.; heating the dehumidified granular polymeric material to a second temperature, greater than the first temperature; drying the granular polymeric material heated to the second temperature, by applying a predefined vacuum level; and transferring the dried granular polymeric material to a feed hopper (40) provided upstream of a working machine (100).

Abstract: A process for drying polymeric granular material (2) comprises the steps of: —introducing into said drying hopper (10) a process gas having a predefined flow rate so as to heat and dry the polymeric granular material, —discharging a portion of the heated polymeric granular material into a transformation unit (100) for the polymeric material; —loading an amount of fresh polymeric granular material (2a) into the drying hopper. The process gas flow rate is regulated by measuring the inlet temperature of the fresh polymeric granular material (2a) and comparing it with a predefined inlet temperature of the fresh polymeric granular material, on the basis of which the predefined process gas flow rate has been calculated. If the measured inlet temperature is different from the predefined inlet temperature, the flow rate of the process gas is regulated on the basis of the measured inlet temperature.