Apparatus and method for dispensing and curing of liquid media

Abstract

The present invention relates to an apparatus for dispensing and curing of liquid media, comprising a supply system comprising at least one reservoir for the liquid medium, a nozzle for ejecting the liquid medium into a mould (10) and/or onto a workpiece and means (22) connecting the nozzle and the reservoir; and a microwave system (16,18) which comprises a microwave source (16) for producing microwave radiation for irradiating the liquid medium in an irradiation zone (20) in the supply system, wherein the irradiation zone (20) is arranged between the reservoir and the nozzle. The apparatus further comprises a displacement assembly for translating and/or rotating the nozzle with respect to the mould (10) and/or the workpiece in a controlled manner. According to further aspects, the invention also relates to a system and a method for dispensing and curing of liquid media.

Claims

1. An apparatus for dispensing and curing of a liquid medium, comprising: a supply system comprising at least one reservoir for the liquid medium, a nozzle for ejecting the liquid medium into a mould and/or onto a workpiece and a rigid pipe connecting the nozzle and the reservoir; and a microwave system which comprises a microwave source for producing microwave radiation for irradiating the liquid medium in an irradiation zone in the supply system, wherein the irradiation zone is arranged between the reservoir and the nozzle, wherein the microwave system further comprises a waveguide for passing microwaves from the microwave source to the irradiation zone; wherein the apparatus further comprises a displacement assembly for translating and/or rotating the nozzle with respect to the mould and/or the workpiece in a controlled manner, wherein the displacement assembly is further arranged to displace the irradiation zone with respect to the mould and/or workpiece in a controlled manner, wherein the displacement assembly is further arranged to displace the waveguide and/or the microwave source with respect to the mould and/or the workpiece together with the irradiation zone, wherein the displacement assembly comprises worm gears or cable pulls together with rail or track assemblies or robotic arm systems, and wherein the waveguide couples the irradiation zone to the displacement assembly.

2. The apparatus according to claim 1, wherein the displacement assembly is arranged to translate the nozzle with respect to the mould and/or the workpiece along at least two perpendicular directions and/or to rotate the nozzle with respect to the mould and/or the workpiece around at least two perpendicular axes.

3. The apparatus according to claim 1, wherein the nozzle is arranged to eject the liquid medium in a substantially vertical downward direction.

4. The apparatus according to claim 1, wherein the irradiation zone and the nozzle are kept a predetermined distance from each other.

5. The apparatus according to claim 1, wherein the rigid pipe is directed in a downward direction.

6. The apparatus according to claim 1, wherein the supply system further comprises a mixing and/or metering device, which is arranged for mixing at least one component and/or for metering an amount and/or a flow rate of the medium to be ejected from the nozzle.

7. The apparatus according to claim 6, wherein a section of the supply system connecting the mixing and/or metering device and the irradiation zone is formed by the rigid pipe, which extends in a vertical downward direction.

8. The apparatus according to claim 1, wherein the apparatus further comprises at least one temperature sensor for sensing the temperature of the liquid medium.

9. The apparatus according to claim 8, wherein the apparatus further comprises a control unit which is adapted to control the microwave source, the displacement assembly, and a mixing and/or metering device and which receives data from the at least one temperature sensor.

10. The apparatus of claim 8, wherein the at least one temperature sensor is associated with the nozzle and/or positioned upstream and/or downstream of the irradiation zone.

11. A system for dispensing and curing of liquid media, comprising at least one mould and the apparatus according to claim 1.

12. A method for dispensing and curing of liquid media, the method comprising: providing the apparatus according to claim 1 and simultaneously displacing the nozzle with respect to the mould and/or the workpiece, ejecting the liquid medium from the nozzle, and operating the microwave source to irradiate the liquid medium in the irradiation zone.

13. The method according to claim 12, wherein during the ejecting the microwave power supplied by the microwave source is adjusted based on a sensed temperature of the liquid medium.

14. The method according to claim 12 wherein the liquid medium is a chemically reactive liquid medium.

15. The method of claim 14, wherein the liquid medium is a reactive resin, wherein the reactive resin is a one-component or a two-component reactive system.

16. A method of forming a three-dimensional (3D) structure, comprising: printing the 3D structure using the apparatus according to claim 1.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) Further advantages and features of the present invention will become even clearer from the following description of an embodiment of the invention with reference to the accompanying figures, wherein:

(2) FIG. 1 is a schematic view of a system for dispensing and curing of liquid media according to the invention comprising a mould; and

(3) FIG. 2 is an enlarged side view of the components of FIG. 1, which are translated by the displacement assembly.

DETAILED DESCRIPTION OF THE INVENTION

(4) FIG. 1 schematically shows a system for dispensing and curing of liquid media, such as a reactive resin, according to the invention, comprising a mould 10 as well as an apparatus 12 for dispensing and curing of the liquid medium. For the sake of visibility, certain components of the apparatus 12 shown in FIG. 2 have been omitted in FIG. 1.

(5) The apparatus 12 is installed vertically above the mould 10 and suspended from a ceiling 14 in a translatable manner by means of a displacement assembly (only schematically shown) along three perpendicular directions X, Y and Z, such that it can be positioned above each point of the mould 10 with a controllable distance in the vertical direction. The displacement assembly comprises three orthogonal rails systems 14a, 14b and 14c along which the movable parts of the apparatus can be moved in X-, Y- and Z-directions The translation along the X-, Y- and Z-directions can for example be driven by cable pull devices which are in turn driven by electric motors and controlled by a control unit 44.

(6) In FIG. 2, the apparatus 12 shown in FIG. 1 is again shown in an enlarged view. It comprises a microwave source 16, which is from a known type, such as e.g. a magnetron. The microwaves produced by the microwave source 16 are coupled into and transferred through a waveguide 18, which is formed as a metallic hollow conductor and comprises a vertical section 18a extending from the microwave source 16 in a vertical downward direction until it turns near its end opposed to the microwave source 16 into a horizontal section 18b.

(7) In said horizontal section 18b, an irradiation zone 20 is provided, such that an aperture extends through the waveguide 18 in a vertical direction in a suitable position taking into account the propagation properties of the geometry of the waveguide and the wavelength provided by the microwave source 16.

(8) A section of a rigid pipe 22 made from a material which is transparent for the microwave radiation produced by the microwave source 16, such as a PTFE material, is guided through the waveguide 18 extending through said aperture and thus through the horizontal section 18b of the waveguide 18.

(9) When the apparatus 12 is in use, a liquid medium, such as a reactive resin, which is supplied from a mixing and metering device 24 is flowing through said rigid pipe 22. The mixing and metering device 24 is positioned horizontally above the irradiation zone 20 and together with the displacement assembly and the microwave source is controlled by the above-mentioned control unit 44 in order to mix components of the liquid medium and meter the output of the medium to a desired flow rate. Since the mixing and metering device 24 is positioned vertically above the irradiation zone 20 and thus the mould 10 (see FIG. 1), the flow of the medium from the mixing and metering device 24 through the pipe 22 into the mould 10 may be driven solely by the effect of gravity.

(10) Below the irradiation zone 20, a nozzle 28 is provided, by means of which the irradiated liquid medium is dispensed from the apparatus 12 into the mould 10.

(11) Since all components of the apparatus 12, including the microwave source 16, the wave guide 18, the nozzle, the irradiation zone 20 and the mixing and metering device 24 are translatable with respect to the mould by means of the displacement assembly, the distance between the irradiation zone 20 and the mould 10 can be kept at a desired constant value while the nozzle is moved along the mould in X and Y directions, such that the liquid medium can enter the mould at each point and at all times with substantially the same temperature and same chemical and physical properties. In order to allow a feedback control, the apparatus 12 may further be provided with at least one temperature sensor 26 for the liquid medium at a suitable position which delivers data to the control unit 44 on the basis of which the output of microwave power by the microwave source 16 can be controlled.