DE102018001145A1 - 3D printer with extendable support structure elements - Google Patents

Abstract

A more significant aspect of fabricating a component by means of a 3D printing process are support structures. Support structures are used to temporarily stop at a location where otherwise the model would have to be printed in free space. This structure is often made of the same material as the model itself and must be removed after printing.
Furthermore, there are powder-based rapid prototyping processes, such. As the selective laser sintering or the electron beam sintering, in each case a loose particulate material is applied in layers and selectively solidified with a controlled laser.
The cost of post-processing currently accounts for about 70 percent of the total spend on 3D printing parts, which in retrospect requires the support structure to be removed.
Furthermore, in powder-based printing processes, in part, only 50% of the excess powder can be reused.
The invention is therefore based on the object of designing a 3D printer in such a way that it offers a simple and cost-saving possibility of reducing the costs for post-processing and for the material
2.2. Solution of the problem or the technical task
This object is achieved by a 3D printing method and a configured for performing the presented method 3D printer according to claims 1 to 10. At the heart of this invention are extendable support structure elements that perform the functions of supporting, cooling and filling hollows.
2.3. field of use
The present invention is particularly useful as a method and apparatus for printing three-dimensional components.

Description

The present invention relates to a method for producing a component by means of a 3D printing method and a 3D printer configured to carry out the method presented.

State of the art:

As state of the art, for example, in the patent EP 0 431 924 B1 a printing method for producing three-dimensional components from CAD files described. In this case, a material is applied in a thin layer on a building platform and this then selectively printed by means of a print head with a binder material. The particle area printed with the binder sticks and solidifies under the influence of the binder and optionally an additional hardener. Subsequently, the platform is lowered into a building cylinder and provided with a new layer of powder material, which is also printed as described above. These steps are repeated until a certain desired height of the object is reached. The printed and solidified areas create a 3D object.

The component made of solidified powder material is then embedded in loose particulate material and is subsequently freed from it. What remains is the desired model.

So work other powder-based rapid prototyping processes, such. As the selective laser sintering or the electron beam sintering in each of which also a loose particulate material is applied in layers and selectively solidified with a controlled laser.

Another widespread 3D printing process is Fused Deposition Modeling (FDM), or Fused Filament Fabrication (FFF), which describes a rapid prototyping process in which a workpiece is built up in layers from a meltable plastic (filament).

In the "melt layer" method, a grid of dots is first applied to a surface, similar to a normal printer. The points are generated by the liquefaction of a wire-shaped plastic or wax material by heating, the application by extrusion through a nozzle and a subsequent hardening by cooling at the desired position in a grid of the working plane.

The structure of a body is carried out by repeated, in each case one line by line traversed work plane and then the working plane, stacking 'is moved upwards, so that a form is formed in layers.

In layered model making, the individual layers combine to form a complex part. Under certain circumstances, cantilevered components can only be produced with supporting structures, which for the most part also arise in layers in the printing process.

An important aspect when producing a component by means of a 3D printing process is the correct orientation of the model. The aim of the preparatory measures is to ensure a high quality. At the same time as little support structure as possible should be used with the correct orientation of the component. Support structure is used to temporarily stop at a place where otherwise the model would have to be printed in free space. This structure is often made of the same material as the model itself and must be removed after printing.

Problem:

The cost of post-processing currently accounts for about 70 percent of total 3D printing spend. Hereby, printed objects have to be reworked, sometimes several days. Post-processing itself is one of the most important areas for optimizing 3D printing, especially when dealing with robust materials.

Furthermore, in powder-based printing processes, which use a laser to weld plastic or metal powders into a finished component, only 50% of the excess powder can be reused.

solution

Against this background, a method for manufacturing a component in a 3D printing process is presented in which at least one support element is selectively extended at least one point of the base or side surfaces during the 3D printing process to temporarily stop at a location where otherwise the model would have to be printed in free space or fill a cavity.

This object is achieved by a 3D printing method with the features of claim 1. Advantageous embodiments and advantageous developments of the invention are specified in the dependent claims.

Achieved benefits:

The advantages achieved by the invention are, in particular, that less material is used for support structures in the printing of 3D components by retractable support structure elements and thereby less time must be expended for the post-processing.

The second major advantage is that the extendable support structure elements occupy a space that otherwise would have to be filled in powder-based printing processes by non-reusable powder material.

Another advantage achieved with this invention is that the extendable support members act as heatsinks for the 3D component and thus actively prevent warping during printing.

list of figures

• 1 3D-Drucker mit hydraulisch ausfahrbare Stützelementen

An embodiment of the invention is illustrated in the drawing and will be described in more detail below.

• 1 3D printer with hydraulically extendable support elements

1 shows a 3D printer configured to perform the procedure presented. The configured 3D printer consists of two parts, an upper part and a lower part. In the upper part, a print object ( 4 Layer by layer of a meltable plastic (filament) from a printhead ( 5 ) on a print bed with through holes ( 3 ) built up.

In the lower part of several hydraulic cylinders are fixed, from which the support elements ( 2 ) can be moved out through the through holes of the print bed.

Much of the support structures for the print object ( 4 ), by the extension of support elements ( 2 ) educated. In the hydraulic cylinder, this is a cooled fluid that for extending and for cooling the support elements ( 2 ) is being used. On the extended support elements, either layers of the print object or further layers of the support structure for the print object are applied directly.

In order to achieve a cooling effect, the print object ( 4 ), further cooled support elements automatically and extended.

LIST OF REFERENCE NUMBERS

1.

hydraulic cylinders

Second

Retractable support elements

Third

Print bed with through holes

4th

print object

5th

printhead

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0431924 B1 [0002]

Claims (10)

A method of manufacturing a component in a 3D printing process, wherein during the 3D printing process at at least one point of a plane, at least one support member is selectively extended to temporarily stop at a location where otherwise the model is printed in free space would. Method according to Claim 1 In which the support elements are driven by a hydraulic and / or pneumatic cylinder and / or linear motor. Method according to at least one of the other methods 1 to 2, wherein the support elements are selectively cooled or heated. Method according to at least one of the other methods 1 to 3, wherein the at least one support element is retracted and extended for the purpose of cooling or heating. Method according to at least one of the other methods 1 to 4, wherein the at least one support element is hollow and has bores from which a fluid for cooling a component exits. Method according to one of the preceding claims, wherein at least one support element consists of a metal. Method according to one of the preceding claims, wherein at least one support element consists of a material which reduces the adhesion to other materials. Method according to one of the preceding claims, wherein at least one support element is extended for the purpose of cavity filling. Method according to one of the preceding claims, wherein at least one support element for lateral support of a component is extended. A 3D printer for manufacturing a component, wherein the 3D printer is configured to selectively extend at least one support member from the print bed to temporarily provide lateral support and / or hold at a location where the model is otherwise printed in free space would.

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