WO2019073100A1

WO2019073100A1 - Hybrid 3d printer

Info

Publication number: WO2019073100A1
Application number: PCT/ES2018/070653
Authority: WO
Inventors: Pablo Fernandez Alvarez; Lorenzo Brito Yebras
Original assignee: Pablo Fernandez Alvarez; Lorenzo Brito Yebras
Priority date: 2017-10-11
Filing date: 2018-10-08
Publication date: 2019-04-18
Also published as: WO2019073100A4; ES1195984U; ES1195984Y; ES1195984U8

Abstract

The 3D printer is of the type that uses the deposition of powder polymer and the subsequent injection of binder as a printing method. The 3D printer of the invention is mainly characterised by the manner of polymer deposition, said polymers being situated on a work surface (2), rather than the deposition being carried out on a sheet of paper. The 3D printer consists of a movable platform (4) which can move vertically and on which a horizontal guide (8) is established, in which guide a polymer deposition drum (9) is located, the polymers being housed in different toners or containers (10). The invention further comprises a system (11) for injecting binder mixed with suitable ink. The invention improves the creation of three-dimensional compositions, since a wider variety of materials can be used and the manufacturing cost is reduced.

Description

3D PRINTER

D E S C R I P C I O N

OBJECT OF THE INVENTION

The present invention relates to a 3D printer, deposition of polymer powder and subsequent injection of binder to produce its polymerization.

The object of the invention is to provide a versatile 3D printer from the point of view of the use of materials, which allows the creation of three-dimensional compositions with different materials and colors in a single print.

More specifically, the object of the invention is to achieve; applying an electrostatic polymer distribution system combined with an inkjet system and supported by a C02 laser system, offering a fully versatile multilateral 3D printer that allows polymerization by: addition of reagents, temperature, photon exposure ... polymers of all; metallic, agglutinable, thermoplastic, photoinitiatable ... with infinite possibilities, all included in a machine that can be very small and very low cost, or in a professional machine very economical and with incredible benefits.

It is also an object of the invention to include a novel toner system for storing the polymers, which is very interesting from the commercial point of view.

BACKGROUND OF THE INVENTION In the field of practical application of the invention, that of the 3D printers, there exists a great diversity of machines that can be divided into the following groups:

By extrusion: these are machines that through an extruder of material, mounted on a guide system X-Y-Z inject the polymer (usually a thermoplastic) to create the composition 3d. These are the most commercialized.

By polymer powder deposition: these machines use a system of drag shovels and a movable platform to deposit layer after layer of polymer powder and then polymerize it; There are two main systems for this; injection of binder and / or reagents, or treat the polymer (mainly metallic) with a C02 laser or similar. To get the polymerization.

By DLP system: these 3d printers use a photopolymer which is introduced into a container with a transparent background to which light is applied in the areas to be polymerized thanks to a DLP projector, it is helped with a movable platform that removes the three-dimensional composition of the deposit as it hardens.

Multimaterial: Very recently there have been some multimaterial printers but with quite a few limitations with regard to the type of material and to which the color already mixed with the different materials must be included since it does not have an independent material and color selection system.

There are basically 2 types:

Those of several extruders, which uses different thermoplastics to make three-dimensional compositions in various plastics. · System "stratasys" that inject through an extruder, liquid polymer which is then treated with UV lamps layer by layer. It is based on a complex system to change materials and the cost of a machine exceeds 100,000 euros.

Thus, current 3D printers either are extremely expensive, or present serious limitations from the point of view of the use of materials. DESCRIPTION OF THE INVENTION

The 3D printer that is recommended resolves in a fully satisfactory way the previously exposed problems, allowing the creation of three-dimensional compositions with different materials and colors in a single impression. For this purpose, the printer of the invention consists of a 3d printer for deposition of polymer powder and subsequent injection of binder to produce the polymerization.

More specifically, and according to the essence of the invention, the novelty of this machine lies in the polymer deposition system, emulating the system of a laser printer, but instead of capturing the polymers on a sheet of paper, depositing the different polymers on a specific surface thanks to the displacement of the transmission drum through a guiding system.

This allows to leave a layer of polymers very precise depositing with the resolution of a laser printer, a polymer or other in the places where it must include one material or another, also allowing to use different charges in some of the toner and mixing them with the different ones polymers in the desired measurements giving the properties chosen in the indicated areas.

This will allow to give different physical properties to the materials changing their conductivity, magnetic properties ... etc, even allowing to print circuits and electrical components.

One of the different toners should include a non-polymeric, ionized inert material, suitable for filling the areas where it will not polymerize, thus drastically reducing the cost of polymers.

After each layer deposited by the transmission belt is added in the different areas to polymerize the appropriate binder with a mixture of inks to give the desired color by ink jet system, taking advantage of the same horizontal displacement guides used by the transmission drum to move the injector through the layer to be treated.

The machine includes a C02 laser of different power according to the needs of the composition of the machine, to polymerize metal areas in substitution or support of the injection system in these areas, allowing to use different metals and metal oxides in powder form as metallic polymers and Many other materials such as thermoplastics, photopolymers and many more.

Also thanks to the characteristics of the model will allow to mix the different metals used, to create different metal alloys with the desired properties in the chosen areas.

Depending on the type of polymer used, the laser can be used as a support for the injector system to dry the pre-agglutinated polymers more quickly.

It also allows the use of baking inks that are treated by the laser layer by layer giving much more finished finishes. According to the number of toners that are included in the model we will have a much more versatile machine but increasing the size of it much, much more suitable for professional use.

This gives the possibilities of realizing 3d models with a great variety of materials and totally in color in a single impression; models with rigid plastic parts, rubber parts, metal parts, as well as different properties in areas of those parts thanks to the adhesion of loads.

The use of conductive materials and materials with different physical properties, such as silicon, or copper gives the possibility of making electrical connections and even components, which opens a wide range of possibilities.

Given the nature of some materials and reagents and taking into account that the invention gives the possibility of using materials that require laser treatment attached to sensitive materials, problems of material compatibility could arise. To overcome the problems of compatibility of the different materials and those that could be affected by the polymerization system of the annexed material, the model itself provides the necessary means to include a thin layer of a suitable transition material, thus solving practically any type of incompatibility.

As for the discharge system, it is a system of discharge by ionic field which can be made in different ways having the same objective according to the needs of the composition.

The unloading system includes a conductive thread or roller that emits a field powerful enough to traverse the material of the transmission belt and repel the polymers adhered to it thus realizing the downloading of the image, it can also include according to the needs of the invention a Faraday cage system open in a thin slot to prevent the field from acting in unwanted areas.

As complement or substitute to the system can be included according to needs of the composition, a plate of a conductive material with electronically controlled power dependent on the distance to which the tray is at the time of discharge, as a system to generate an opposite field in the movable tray in which it attracts the polymers adhered to the transmission belt. It is also possible to use a discharge blade also made of conductive material to support the physical scraping of the blade with a suitable field, placing the blade against the transmission belt of the polymers in the polymer discharge zone. These systems can be combined or used independently to make the machine according to the composition best suited to the needs.

As for ionized polymers, ionized polymers of a very specific size have to be used. These are introduced into different toner deposits in the same way as a color laser printer. A system for the addition of ionized powder by electrostatic system employs a pre-ionized drum, and selectively deionized by laser that collects the polymers from the rollers of the different toners forming an image.

Unlike conventional laser printers that capture this image on paper, this innovative system deposits the different polymers layer after layer on a work surface on which the 3D model is formed.

The photosensitive drum is adhered to the different polymers creating the image of each of the layers using the laser printing system. Then each layer is adhered to the transmission belt which is composed of an electrostatically charged ionizable material. The transmission is carried out thanks to a transmission roller, which thanks to an electric current generates a field of attraction.

When the image is adhered to the transmission belt, this thanks to the guide system moves on the work surface depositing the polymers layer by layer moving the transmission drum by a guide system and using an ionized discharge roller that thanks to a current electric, generates a field that repels the polymers, allowing them to be detached as it passes through the work surface, effecting the discharge of the transmission drum and thus leaving the previously captured image, like a thin layer of very precise polymers on the work surface.

The machine, with the resolution of a laser printer, deposits one polymer or another in the places where it must include one material or another and that after being treated suitably by the injector system and / or the C02 laser, they are displaced by a mobile platform, with vertical displacement regulated by a stepper motor and an endless screw.

The transmission drum moves down the exact measurement of the thickness of a layer, thus allowing the next layer to be deposited on the last one treated.

The model includes for its correct operation an inkjet system similar to those used commercially, but with displacement by 2 axes X - Y equal to that used by other 3D printers of powder deposition.

After each layer deposited by the transmission drum, this injection system adds in the different areas to polymerize the appropriate binder with a mixture of inks to give the desired color and add the reactive agent, necessary for the polymerization.

The attainment of layers one after another results in a 3D model buried by the dust of the untreated areas. When removing the unpolymerized powder we will find the three-dimensional figure composed of the union of the different layers.

As has been said before, a C02 laser of different power is also included according to the needs of the composition of the machine, guided by a system of mirrors.

The objective of the laser is to polymerize certain areas, in substitution or support of the injection system, allowing to use different metals and metal oxides in powder form as metallic polymers and many other materials; such as thermoplastics, photopolymers, etc.

Depending on the type of polymer and / or reagent used, the laser can be used as a support for the injector system to dry the previously bound polymers more quickly or to excite a photoactive agent. This C02 laser is not necessary for the functionality of the model, but it greatly increases its usefulness.

From this structuring, the electrostatic deposition system allows to make very precise mixtures of the different materials included in the toners allowing also to mix the different polymers with each other, to use different charges in some of the toner deposits and to mix them with the different polymers in the desired measures to give them the desired properties in the zones indicated. This will allow to give different physical properties to the materials to change their conductivity, physical magnetic properties ... etc, even allowing to print circuits and functional electrical components.

One of the different toners may include an inert, non-polymeric, ionized material suitable for filling the areas in which it will not polymerize, thus drastically reducing the cost of polymers.

It only remains to note finally that, to be able to support the system with less maintenance and help in the construction of small parts that require a lot of inert material, the model includes an endless screw system to drag inert material to a deposit of fixed toner, located on the other tanks and supported mainly by the screw system and an unloading and distribution tray, which ensures the correct distribution of the material by the toner tank from a front drawer where the inert material is stored.

DESCRIPTION OF THE DRAWINGS To complement the description that will be made next and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical realization thereof, it is accompanied as an integral part of said description, a set of plans where, with an illustrative and non-limiting character, the following has been represented: Figure 1 shows an antero-superior perspective view of a 3D printer made according to the object of the invention.

Figure 2 shows a rear-top perspective view of the printer of the previous figure.

Figure 3 shows an antero-superior perspective view of the main internal structure of the printer.

Figure 4 shows, finally, a posterior-superior perspective view of the assembly of the previous figure. PREFERRED EMBODIMENT OF THE INVENTION

In view of the figures outlined, it can be seen how the 3D printer of the invention is constituted, as is conventional, from a housing (1), in which a 3D printing zone (2) is defined, duly protected by a door (3), in which a movable platform (4) is established, specifically vertically displaceable through lateral guides (5) and by means of a screw (6), so that the horizontal printing plane is always at a constant height being, the 3D model (7) which moves little by little downwards as it is obtained. In accordance with the essence of the invention, the printer has a pair of horizontal guides (8), parallel to the printing plane, on which a drum (9) of polymer deposition, which acts analogously to a laser printer, only that instead of capturing the polymers on a sheet of paper, it deposits the different polymers housed in the different tanks (10) or toners on the work surface, either initially on the mobile platform (4) or on the different horizontal layers of the model (7) that is obtained, thanks to the displacement of the drum (9) by the guides (8), also allowing to use different loads, mix the different polymers of the tanks (10) in the desired measurements giving the model (7) the properties chosen in the indicated areas.

Additionally, and in accordance with another of the fundamental characteristics of the invention, on said guide system is also displaceable an injection system (11), responsible for adding in the different areas to polymerize the appropriate binder with a mixture of inks for giving the desired color, so that said injection system moves precisely on the layer previously deposited by the drum (9).

As has been said before, one of the different deposits (10) or toners should include a non-polymeric, ionized inert material, suitable for filling the areas where it will not polymerize, thus drastically reducing the cost of polymers .

Optionally, the machine includes a laser (12) of C02 of different power according to the needs of the composition of the machine, to polymerize metal areas in substitution or support of the injection system (11) in these areas, allowing to use different metals and metal oxides in powder form as metallic polymers and many other materials such as thermoplastics, photopolymers and many more.

This will allow to mix the different metals used, to create different metal alloys with the desired properties in the chosen areas.

In the same way, and depending on the type of polymer used, the laser (12) can be used as a support for the injector system to dry the previously agglutinated polymers more quickly.

The use of the laser (12) also allows the use of baking inks that are treated by the laser layer by layer giving much more finished finishes.

As mentioned above, as a complement or substitute to the system can be included according to needs of the composition, a plate of a conductive material with electronically regulated power dependent on the distance to which the tray is at the time of discharge , as a system to generate an opposite field in the displaceable tray in which it attracts the polymers adhered to the transmission belt. It is also possible to use a discharge blade also made of conductive material to support the physical scraping of the blade with a suitable field, placing the blade against the transmission belt of the polymers in the polymer discharge zone.

These systems can be combined or used independently to make the machine according to the composition best suited to the needs. The achievement of layers one after another applied alternately by the transition drum (9) and the injection system (11) results in a 3D model buried by the dust of the untreated areas.

When removing the unpolymerized powder we will find the three-dimensional figure composed of the union of the different layers.

It only remains to note finally that, to be able to support the system with less maintenance and help in the construction of small parts that require a lot of inert material, the model includes an endless screw system (13) to drag inert material to a storage tank. fixed toner (14), located on the other tanks (10) and supported mainly by the screw system and a discharge and distribution tray, which ensures the correct distribution of the material by the toner container from a front drawer (15). ) where the inert material is stored.

Claims

R E I V I N D I C A C I O N S

1 .- 3D Printer, characterized in that it is formed from a housing (1), wherein an area of 3D (2) printing, in which a mobile platform (4), provided with displacement means participates defined controlled vertical, area on which a horizontal guidance system (8) is established, parallel to the printing plane, in which a polymer deposition drum (9), housed in different tanks (10) or toners, is movable. horizontal guide (8) on which an injection system (11) of the suitable binder with a mixture of inks on the polymer layer previously deposited on the printing area is also displaceable.

2 .- 3D printer according ^to claim 1, wherein the drum (9) deposition of polymers includes means for employing different loads and mixing of the different polymers from deposits (10) measures desired. 3 .- 3D printer according to claims 1 and 2, wherein one reservoir (10) or toners include an inert non - polymeric ionized material to fill in the areas where it will not polymerize.

4 .- 3D printer according ^to claim 1, wherein the machine includes a laser (12) C02 polymerization of metal areas, creating different metal alloys, polymers agglutinated previously drying and baking ink.

5 .- 3D printer according ^to claim 1, wherein the drum (9) deposition polymer includes a discharge system ionic field.

6 .- 3D printer according ^to claims 1 and 5, wherein the drum includes a belt transmission polymers associated with a wire or conductive roller repulsion polymers attached to said belt.

7 ^a .- 3D printer, according to previous claims, characterized in that it includes an open Faraday cage system as a control element of the ion field. 8 .- 3D printer according to claims 1 ^to 6, wherein the drum includes a discharge blade of conductive material in opposition to the transmission belt of the polymers in the discharge zone of said polymers.

9 ^a .- 3D printer, according to previous claims, characterized in that it includes a screw system (13) to drag inert material to a fixed toner tank (14).