FUSED DEPOSITION MODELING BASED MOLD FOR MOLDING, AND REPLICATING OBJECTS, METHOD FOR ITS MANUFACTURE AND FUSED DEPOSITION MODELING 3D PRINTER

Abstract

The invention provides a method for manufacturing a 3D item (10), wherein the 3D item (10) comprises an outer layer (210) and a support structure (220) with cavities (230), wherein the outer layer (210) at least partly encloses the support structure (220), and wherein the method comprises: (a) a 3D printing stage comprising 3D printing with fused deposition modeling (FDM) 3D printable material (201) the outer layer (210) and the support structure (220) and at least partly filling the cavities (230) with a filler material (204); and (b) a post-treatment stage comprising post treating at least part of the outer layer (210) for reducing surface roughness.

Claims

1. A method for manufacturing a 3D item, wherein the 3D item comprises an outer layer and a support structure with cavities, wherein the outer layer at least partly encloses the support structure, and wherein the method comprises: (a) a 3D printing stage comprising 3D printing with fused deposition modeling 3D printable material the outer layer and the support structure and at least partly filling the cavities with a filler material; and (b) a post-treatment stage comprising post treating at least part of the outer layer for reducing surface roughness.

2. The method according to claim 1, wherein the 3D item is a mold.

3. The method according to claim 1, wherein the 3D printable material comprises a curable material, and wherein the 3D printing method includes curing at least part of the printable 3D printable material to provide 3D printed material.

4. The method according to claim 1, wherein the filler material comprises a material having a higher thermal conductivity than the support structure.

5. The method according to claim 4, wherein the filler material before filling the cavities comprises a slurry comprising one or more of metal particles, ceramic particles, and carbon particles, and wherein the method further comprises a transformation stage comprising transforming the slurry in the cavities in a solid filler material, wherein the transformation stage includes one or more of curing and drying.

6. The method according to claim 1, wherein the post-treatment stage comprises one or more of heating at least part of the outer layer, solvent dissolving at least part of the outer layer, and coating at least part of the outer layer, and wherein the thus obtainable outer layer and the support structure differ in one or more of chemical composition, density, and surface texture.

7. A method for producing an object, wherein the method comprises at least partly filling a mold obtainable by the method according to claim 1 with a curable material, at least partially curing said curable material to provide said object comprising cured material, wherein the mold comprises an outer layer and a support structure with cavities, wherein the outer layer at least partly encloses the support structure, and wherein the cavities are at least partly filled with filler material, and removing the object from said mold, wherein the filler material comprises a material having a higher thermal conductivity than the support structure.

8. The method according to claim 7, wherein the curable material comprises a silicone, and wherein the object comprises an optical component.

9. The method according to claim 7, wherein the outer layer and the support structure differ in one or more of chemical composition, density, and surface texture.

10. A mold obtainable by the method according to claim 1 and comprising an outer layer and a support structure with cavities, wherein the outer layer at least partly encloses the support structure, wherein the cavities are at least partly filled with filler material, and wherein the filler material comprises a material having a higher thermal conductivity than the support structure.

11. The mold according to claim 10, wherein the outer layer and the support structure differ in one or more of chemical composition, density, and surface texture.

12. A fused deposition modeling 3D printer comprising a printer nozzle and a filler material dosing unit, wherein the 3D printer is configured to provide a 3D item comprising an outer layer and a support structure with cavities, wherein the outer layer at least partly encloses the support structure, and wherein the cavities are at least partly filled with filler material, wherein the 3D printer further comprises a post-treatment stage unit configured to post treat at least part of the outer layer of the 3D item for reducing surface roughness.

13. The 3D printer according to claim 12, further comprising a transformation stage unit configured to transform a slurry in a solid filler material, wherein the slurry comprising one or more of metal particles, ceramic particles, and carbon particles, and wherein the transformation stage unit is configured to cure and/or dry the slurry; and wherein the post-treatment stage unit is configured to apply one or more of heating at least part of the outer layer, solvent dissolving at least part of the outer layer, and coating at least part of the outer layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0040] FIG. 1 schematically depicts an embodiment of a 3D item, such as a mold;

[0041] FIGS. 2a-2b schematically depict a non-limiting number of embodiments for producing the 3D item, such as a mold;

[0042] FIG. 3a schematically depicts an enlargement of part of the 3D item of FIG. 1 before and after the post-treatment stage;

[0043] FIG. 3b schematically depicts another enlargement of an embodiment of the mold, after post-treatment;

[0044] FIGS. 4a-4b schematically depict some aspects of the 3D printer.

[0045] The drawings are not necessarily on scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] FIG. 1 schematically depicts a 3D item 10, especially a mold 20, comprising an outer layer 210 and a support structure 220 with cavities 230, wherein the outer layer at least partly encloses the support structure 220, and wherein the cavities 230 are at least partly filled with filler material 204. The bulk of the item 10 is indicated with reference 200. The bulk 200 may especially comprise the support structure 220, including cavities 230. Further, in the present invention one or more cavities 230 comprise filler material 204. Hence, in the object of the invention, the bulk 200 may also comprise the filler material 204. The material of the outer layer 210 and the support structure 220 may in embodiments be essentially identical. The filler material 204 will in general differ in composition from the support structure material.

[0047] Assuming the 3D item 10 to be a mold 20, as schematically depicted here, the mold 20 may include a mold opening or mold cavity, which is indicated with reference 22, and which is used to produce at least a part of a 3D object in, as is known from state of the art mold processing. Reference 222 indicates an outer layer of the support structure. Due to the post treatment of the 3D item 10, the outer layer 222 of the support structure will remain untreated whereas the outer layer 210 (or at least its surface) will be treated. This especially leads to differences, especially in the surfaces thereof. For instance, they may differ in one or more of (a) chemical composition, (b) density, and (c) surface texture.

[0048] FIGS. 2a-2b schematically depict non-limiting steps of the process of manufacturing the 3D item 10, but not including the post treatment stage. These figures focus on the 3D printing stage. The filler material before filling the cavities may comprises a liquid, such as a slurry 205 comprising one or more of metal particles, ceramic particles, and carbon particles, and wherein the method may further comprise a transformation stage comprising transforming the slurry in the cavities in a solid filler material 204, wherein the transformation stage includes one or more of curing and drying. Herein, the liquid is further described with reference to a slurry 205, though liquids others than slurries may also be applied (and optionally transformed into filler material 204). Hence, the printing stage may e.g. include one or more of injecting and dispensing the filler material (or a precursor thereof such as a liquid, like slurry 205). Reference 202 indicates 3D printed material. When printing, the 3D printable material is flexible, whereas the 3D printed material is more rigid than the 3D printable material, as known in the art. One may in an embodiment print the 3D printable material and fill with filler material (or its precursor) at the same time, or use a plurality of 3D printing and filling steps, and thereby step by step generate the (ready) 3D item (see FIG. 2a). Alternatively, one may first at least partly, or even substantially entirely create the 3D support structure (and the outer layer 210), and then fill with filler material FIG. 2b). In both schematically depicted process embodiments, the filler material is provided as fluid filler material (slurry) 205, and then dried and/or cured. However, also other embodiments are possible, including filling with particulate filler material 204. Hence, FIGS. 2a-2b schematically depict a non-limiting number of embodiments for producing the 3D item, such as a mold 20.

[0049] FIG. 3a schematically depicts an enlargement of part of the 3D item of FIG. 1 before and after the post-treatment stage. Before the post-treatment, the surface texture is relatively rough, and this applies for the outer layer 210 as well as the support structure 220. However, after the post treatment, the outer layer 210 may have been subjected to one or more methods for reducing surface roughness. The result is schematically depicted after the arrow. Such treatment will have no or less effect on the underlying support structure 220 (and the remainder of the 3D printed material 202). FIG. 3b schematically depicts another enlargement of an embodiment of the mold, after post-treatment. Here, the post-treatment may e.g. have been included a coating step. A coating 217 is depicted, which reduces the surface roughness of the outer layer 210 relative to the uncoated outer layer 210.

[0050] FIGS. 4a-4b schematically depict some aspects of the 3D printer. Reference 500 indicates a 3D printer. Reference 530 indicates the functional unit configured to 3D print, especially FDM 3D printing; this reference may also indicate the 3D printing stage unit. Here, only the printer head for providing 3D printed material, such as a FDM 3D printer head is schematically depicted. Reference 501 indicates the printer head. The 3D printer of the present invention may especially include a plurality of printer heads, though other embodiments are also possible. Reference 502 indicates a printer nozzle. The 3D printer of the present invention may especially include a plurality of printer nozzles, though other embodiments are also possible. Reference 320 indicates a filament of printable 3D printable material (such as indicated above). For the sake of clarity, not all features of the 3D printer have been depicted, only those that are of especial relevance for the present invention. The 3D printer 500 is configured to generate a 3D item 10 by depositing on a receiver item 550 a plurality of filaments 320 wherein each filament 20 comprises 3D printable material, such as having a melting point T.sub.m. The 3D printer 500 is configured to heat the filament material upstream of the printer nozzle 502. This may e.g. be done with a device comprising one or more of an extrusion and/or heating function. Such device is indicated with reference 573, and is arranged upstream from the printer nozzle 502 (i.e. in time before the filament material leaves the printer nozzle 502). Reference 572 indicates a spool with material, especially in the form of a wire. The 3D printer 500 transforms this in a filament or fiber 320. Arranging filament by filament and filament on filament, a 3D item 10 may be formed.

[0051] FIG. 4b schematically depicts an embodiment of the 3D printer 500 including a post-treatment stage unit 510. The 3D printer comprises a printer stage unit 530, which at least comprises a printer head for printing with 3D printable material (see FIG. 4a). Optionally, this printer stage unit 530 may comprise a material dosing unit 504, configured to provide filler material. Also optionally, especially in combination with the material dosing unit 504, the printer stage unit 530 may comprise a transformer stage unit 520. Especially, the transformation stage unit 520 may be configured to transform a slurry 205, e.g. provided by the material dosing unit 504, in a solid filler material 204. As the material dosing unit 504 and the transformation stage unit 520 are optionally included in the printer stage unit 530, dashed lines are used. Further, the 3D printer 500 may optionally comprise a post treatment unit 510. Optionally, the 3D printer device may include transporting means (not depicted) to transport the 3D printer from one stage to another stage. More functional elements and/or units than the herein schematically indicates elements and/or units may be comprised by the 3D printer 500.

[0052] It goes without saying that other features can be built into such a mold. For example when water cooling is needed during the use of the mold, then suitable channels can be designed and brought into the mold for enabling water cooling.

[0053] The term “substantially” herein, such as in “substantially consists”, will be understood by the person skilled in the art. The term “substantially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially may also be removed. Where applicable, the term “substantially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term “comprise” includes also embodiments wherein the term “comprises” means “consists of”. The term “and/or” especially relates to one or more of the items mentioned before and after “and/or”. For instance, a phrase “item 1 and/or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term “comprising” may in an embodiment refer to “consisting of” but may in another embodiment also refer to “containing at least the defined species and optionally one or more other species”.

[0054] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0055] The devices herein are amongst others described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation or devices in operation.

[0056] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb “to comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0057] The invention further applies to a device comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

[0058] The various aspects discussed in this patent can be combined in order to provide additional advantages. Furthermore, some of the features can form the basis for one or more divisional applications.

Experimental

[0059] Molds with support structure were made. The support structures and outer layers were e.g. made of ABS, poly styrene or PC. The cavities in the support structure were filled with highly thermally conductive graphite composite (graphite as filler material).

[0060] Two different parts were brought on top of each other and a molding cavity, i.e. the cavity which is used to fill with polymerizable material for creating a 3D object, is then filled with liquid silicone which is then polymerized. Subsequently the mold is heated and the silicon polymerizes (is cured). The mold is opened and the molded object is released. Different types of molds were used, some of which were made without the filler material and post-treatment for surface smoothening, some with only the post-treatment, some with only the filler material, and some with both the filler material and the post-treatment. An FDM made mold without surface treatment and filler material could not be used for replicating technologies. The mold deforms. The same applies to the molds with surface treatment but without the filler material. Some of the surface treatments, such as heating, lead to a deformation of the mold. Those with filler material were able to withstand replicating conditions such as elevated temperatures. However, only the mold after the post-treatment provided a 3D item that had a smooth surface and could be relatively easily removed from the mold. A lens with a relatively very smooth surface was obtained.