METHOD FOR REMOVING MOISTURE FROM POLYMER PELLETS FOR PLASTIC INJECTION AND EXTRUSION

Abstract

The invention relates to a solution for reducing and removing moisture from plastic pellets by means of absorption and condensation, in which energy consumption is reduced and the process is simplified, making use of infrared wavelength efficiency, and comprising the following steps: 1. a supply phase using a dosing tank; 2. a distribution phase using a pellet levelling and dispensing device, a conveyor belt and a vibrating motor on the conveyor belt; 3. a moisture-removal phase using one or more infrared wave emitters disposed in parallel, a ventilated or cooled motor for a set of emitters, an air-recirculation passage for a set of emitters, an input temperature probe, an output temperature probe, and a moisture control probe; and 4. a discharge phase in which the material from which the moisture has been removed is discharged using a thermally-insulated collector tank.

Claims

1. A method for removing moisture from polymer pellets for plastic injection and extrusion characterised in that it comprises a 1st supply phase using a dosing tank, with or without stirrer, and with or without thermal insulation; a 2nd distribution phase using a pellet levelling and dispensing device, a conveyor belt and a conveyor belt and a vibrating motor on the conveyor belt; A 3rd moisture-removal phase using one or more infrared wave emitters disposed in parallel, a ventilated or cooled motor for a set of emitters, an air-recirculation passage for a set of emitters, an input temperature probe, an output temperature probe, and a moisture control probe; and finally, a discharge phase in which the material from which the moisture has been removed is discharged using a thermally-insulated collector tank.

2. Procedure for moisture removal from polymer pellets for plastic injection and extrusion for materials considered highly hygroscopic in accordance with claim 1, characterised in that it comprises one or more emissions of infrared waves with a wavelength of 2-3.2 μm.

3. A procedure for moisture removal from polymer pellets for plastic injection and extrusion for materials considered hygroscopic in accordance with claim 1 characterised in that it comprises one or more emissions of infrared waves with a wavelength of 1.6-2.0 μm.

4. A procedure for moisture removal from polymer pellets for plastic injection and extrusion for materials considered hygroscopic in accordance with claim 1 characterised in that it comprises one or more emissions of infrared waves with a wavelength of 1.4-1.6 μm.

5. A procedure for moisture removal from polymer pellets for plastic injection and extrusion for materials considered hygroscopic in accordance with claim 1 characterised in that it comprises one or more emissions of infrared waves with a wavelength of 0.9-1.4 μm.

6. A procedure for moisture removal from polymer pellets for plastic injection and extrusion in accordance with claim 1 characterised in that an ancillary suction pump can be used in the dosing tank.

7. A procedure for moisture removal from polymer pellets for plastic injection and extrusion in accordance with claim 1 characterised in that a cleaning brush system can be used on the conveyor belt.

Description

HOW THE INVENTION IS CARRIED OUT

[0049] The method for removing moisture from polymer pellets for plastic injection and extrusion is based on the infrared spectrum wavelength efficiency of the materials to be treated, which are of four types: [0050] TYPE 1: Wavelength of 2-3.2 μm for materials considered highly hygroscopic [0051] TYPE 2: Wavelength of 1.6-2.0 μm for hygroscopic materials [0052] TYPE 3: Wavelength of 1.4-1.6 μm for non-hygroscopic materials. [0053] TYPE 4: Wavelength of 0.9-1.4 μm for amorphous materials

[0054] These types are distributed in one or more wavelength emitters in parallel and combined in a set or not, depending on the hygroscopy of the product to be treated, by a procedure in successive phases with the provision of the following technical resources: [0055] 1. —A dosing tank, with or without a stirrer and with or without thermal insulation [0056] 2. —A pellet levelling and dispensing device [0057] 3. —One or more infrared wave emitters disposed in parallel arranged wavelength of greatest efficiency (Type 1 to Type 4) [0058] 4. —A ventilated or cooled motor for a set of emitters [0059] 5. —An air recirculation passage for a set of emitters [0060] 6. —An input temperature probe [0061] 7. —An output temperature probe [0062] 8. —A moisture control probe [0063] 9. —A conveyor belt [0064] 10. —A vibrating motor on the material conveyor belt [0065] 11. —A thermally insulated collector tank

[0066] A 1st supply phase is carried out with a dosing tank, with or without stirrer and with or without thermal insulation (1); A 2.sup.nd distribution phase takes place through a pellet levelling and dispensing device (2), a conveyor belt (9) and a vibrating motor on the material conveyor belt (10); A 3.sup.rd moisture removal phase is carried out by one or more infrared wave emitters in parallel (3), a ventilated or cooled motor for a set of emitters (4), an air recirculation passage for a set of emitters (5), an input temperature probe (6), an output temperature probe (7) and a moisture control probe (8); and finally, a 4th phase of discharge of the material from which the moisture has been removed to a thermally insulated collector tank.

[0067] With regard to the type of relationship between the efficiency of wavelength and the materials to be treated explained above, it can be deduced that the following wavelengths in one or more infrared wave emitters should be used, according to the private tests carried out: A wavelength of 2-3.2 μm for materials considered highly hygroscopic (TYPE 1); a wavelength of 1.6-2.0 μm for hygroscopic materials (TYPE 2); a wavelength of 1.4-1.6 μm for non-hygroscopic materials (TYPE 3); and a wavelength of 0.9-1.4 μm for amorphous materials (TYPE 4).

[0068] Optionally, an ancillary suction pump may be used in the dosing tank, and a cleaning brush system may be used on the conveyor belt.