WO2021252828A1

WO2021252828A1 - 3d printing wax build for casting

Info

Publication number: WO2021252828A1
Application number: PCT/US2021/036912
Authority: WO
Inventors: Laura A. Kiefer; Yong Joon Lee
Original assignee: Solidscape, Inc.
Priority date: 2020-06-12
Filing date: 2021-06-11
Publication date: 2021-12-16

Abstract

A 3D printable wax material which primarily comprises Carnuba Wax. In addition, the 3D printable wax material further comprises at least one of a casting wax or a polymer.

Description

[0001] 3D PRINTING WAX BUILD FOR CASTING

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a novel 3D printable wax material , for a three dimensional (3D) printing system, which primarily comprises a wax material.

[0004] BACKGROUND OF THE INVENTION

[0005] It is to be appreciated that wax, forming a 3D print build material, is usually solid at ambient temperature and, therefore, must be dispensed at elevated temperature. The heated fluid will rapidly solidify once the wax material comes to contact with the target substrate. There have been many studies for a hot melt wax as 2D jet ink as shown in, for example, see U.S. Patent Nos. 3,653,932, 3,715,219, 4,390,639 and 4,484,948. Examples of 3D modeling processes are described in, for example, U.S. Patent Nos. 4,247,508, 5,136,515, 5,260,009, 5,506,607, 5,740,051 and 6,175,422.

[0006] In typical embodiments of the 3D modeling processes, the modeling and sacrificial materials comprise two materials having differing mechanical and/or chemical characteristics with the differences between the modeling and the sacrificial materials being such that the sacrificial material, following completion of the fabrication process, can be selectively removed thereby leaving only the modeling material. For example, in some implementations the sacrificial material may have a lower melting temperature than the modeling material or may be dissolvable by a solvent that only interacts with the sacrificial material but does not effect the modeling material.

[0007] Less common implementations of 3D modeling processes, which are not pertinent to the present invention, may construct the part and its model sacrificial regions from a single material having two different physical states or phases, depending, for example, upon whether a given region has been radiated by a specific type of laser radiation or has been treated with a binding agent or solvent, thereby converting treated and untreated regions of the material into the equivalent of modeling and sacrificial material.

[0008] The layers, e.g., of the modeling and/or sacrificial materials, are typically laid down one layer at a time and one region or line of material at a time, e.g., either by a drop-by-drop deposition of the desired material or a rapid deposition of the desired material, onto a previous layer or a base by corresponding drop-on-demand print heads, generally similar to those used in inkjet printers, or by a rapid deposition print heads. Each layer is then planed to form a level, uniform surface upon which the next subsequent layer of the modeling and/or the sacrificial materials may be then subsequently deposited. This process is then repeated numerous time to fabricate the desired 3D model.

[0009] System that utilize two different materials, that is, the model material and the sacrificial material, will therefore require at least one drop-on-demand or rapid deposition print head for the model material and at least one drop-on-demand or rapid deposition print head for the sacrificial material, and the position and the motion of each of the print heads must be controlled to the intended point or area where the desired material, e.g., the model or the sacrificial material, is to be deposited. It must also be noted that each of the sacrificial or the model materials are ejected from the corresponding drop-on-demand or rapid deposition print heads in a molten or liquid or semi-liquid state and such ejected material then rapidly solidifies as soon as ejection is deposited as part of the layer currently being laid down or deposited on layer currently being “fabricated.” This process is fundamental to the operation of drop-on-demand type and rapid deposition print heads and additionally allows each drop or deposited material to adhere to the previously deposited and solidified drops or material, including those of the previously deposited layer, before subsequently hardening.

[0010] The depositing of the drops or the rapidly deposited sacrificial or the model material, in a liquid or semi-liquid state, requires that each drop of the material to be deposited onto a supporting surface, typically the previously deposited layer. This, in turn, requires that each layer extend at least the maximum horizontal extent of the part above that layer, including those areas of a layer that lie under any overhanging or undercut regions of the part being fabricated, although such temporary supporting areas of the layers may be subsequently removed once the fabrication process is completed.

[0011] In addition, a typical 3D modeling process, according to the prior art, will lay down a layer by first depositing the model material, that is, constructing a one layer thick section of the part itself, and then filling in the remainder of the layer area with the sacrificial support material, so that the sacrificial support material functions only as a support for the next subsequent layer. This sequence of deposition, however, means that the dimensions, the texture and the quality of the finished part is determined solely by the qualities and the characteristics of the model material which are, in turn, largely determined by the characteristics required to form an initially free-standing structural element. The result, however, is to limit the characteristics of the model material in a way that is determined more by the modeling process than by the desired final characteristics of the finished part, so that the desired material and finish characteristics of the finished part often cannot be satisfactorily achieved.

[0012] The present invention addresses these and other related problems of the deposition prior art 3D materials.

[0013] SUMMARY OF THE INVENTION

[0014] Wherefore, it is an object of the present invention to overcome the above mentioned shortcomings and drawbacks associated with the prior art.

[0015] Another object of the present invention is to provide a new and improved build material which for use in a 3D printing system in which the improved build material comprises a natural wax component including at least one Carnauba wax as well as derivatives thereof.

[0016] A further object of the present invention is to provide a new and improved build material which comprises a Carnauba wax mixture or a composition of different grades and/or different derivatives of the Carnauba wax.

[0017] A still further object of the present invention is provide a new and improved build material which comprises a Carnauba wax composition which comprises at least the Carnauba wax as well as at least one of additional component selected from the group consisting of an antioxidant, a surfactant, a viscosity controller, a surface active agent and/or a plasticizer.

[0018] Yet another object of the present invention is to provide a simple Carnauba wax mixture or composition with a formulation of non-toxic and hypoallergenic waxes which primarily comprising the build ingredients.

[0019] Still another object of the invention is to select the physical properties, such as a melting point, a viscosity, etc., of the build material so as to be consistent with the 3D printing jetting parameters for a desired application. [0020] The present invention generally relates to a formula comprising of Carnuba Wax and at least one polymer, which may or may not be miscible (compatible), such as polyethylene utilized in a percentage, by weight, of between 5% polyethylene and about 50% polyethylene, typically between about 10-20% polyethylene, by weight.

[0021] The present invention also relates to using a casting wax (30-80 Blue Cerita Casting Wax by Paramelt of Costerstraat 18, 1704 RJ HEERHUGOWAARD, Netherlands) which is generally miscible. Positive results were achieved with up to 50% of the second component. The Inventors are also screening beeswax as a second component (this will require a new dewaxing solvent) and will start screening paraffin wax soon.

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present invention will be understood by reference to the following detailed description, which should be read in conjunction with the appended drawings. It is to be appreciated that the following detailed description of various embodiments is by way of example only and is not meant to limit, in any way, the scope of the present invention.

[0023] The present invention generally relates to two formulas for the wax, the first formula is about 90% Carnuba and about 10% Polyethylene, while the second formula is between about 80 to 90% Carnuba and between about 10-20% 30-80 Blue.

[0024] As described in the following description, the present invention relates to a build material which primarily comprises a wax component. The wax component comprises at least one Carnauba wax, and/or one or more derivatives thereof or one or more synthetic substitute waxes thereof. According to the disclosure, a “Carnauba wax” (CAS number 8015-86-9) is obtained from the leaves of the palm tree and is also known as Copernica Cerifera or a Brazil wax. Typically, a Carnauba wax consists of fatty acid esters (80%-85%), fatty alcohols (10%-16%), acids (3%- 6%) and hydrocarbons (1%-3%). Generally, the Carnauba wax is around 20% esterified fatty diols, 10% methoxylated or hydroxylated cinnamic acid, and 6% hydroxylated fatty acids.

[0025] Carnauba wax is compatible with most vegetable waxes and mineral waxes as well as a large variety of natural and synthetic resins. [0026] The Carnauba wax typically has a melting point range between 80°C to 87°C. Once solidified, the Carnauba wax is typically harder than concrete and nearly insoluble in water and ethanol. As such, the Carnauba wax has excellent characteristics and qualities for a variety of different build applications.

[0027] In addition, the Carnauba wax is non-toxic and hypoallergenic and thus suitable for many build applications. Further, due to its characteristics, a 3D model, manufactured from the Carnauba wax according the present disclosure, can be polished to high gloss and thereby has excellent finished qualities.

[0028] Depending upon the particular application, the Carnauba wax, including one or more derivatives and/or one or more synthetic substitutes thereof, which forms the build material for a 3D application, may include other compatible resins or waxes so as to form the Carnauba wax composition. For example, the Carnauba wax composition may include one or more of the following additional constituents: an antioxidant(s), a viscosity control agent(s), a surfactant(s), a surface active agent(s) and/or a plasticizer(s).

[0029] For some applications, the Carnauba wax may be chemically reacted with synthetic resins to form a high molecular weight (mono)ester. The high molecular weight (mono)ester - called PEG 12 modified Carnauba - can be used as a main component in the build material as described in the present disclosure or can be used as a stabilizer when the Carnauba wax is physically blended with one or more other resins.

[0030] It is to be appreciated the Carnauba wax composition, depending upon the specific application as well as the specific composition, may have a wide melting range from about 95°C to about 100°C.

[0031] It is to be appreciated that the build materials be designed, depending upon the formulation of the Carnauba wax composition, to have a melting point and a freezing pointing (crystalization point) consistent with the desired 3D printing temperature parameters. Moreover, for some embodiment, the build material may have a freezing point temperature range (or setting points or crystallization points) of 70°C to 85°C. For other application, the build material may have a broader freezing range of about 45°C to about 100°C depending on the composition of the build material.

[0032] For some embodiments of the disclosure, the build material may have a viscosity, at a temperature of about 120°C, ranging from about 10 centipoise to 30 centipose.

[0033] In some embodiments, the build material is non-curable.

[0034] For one application, the Carnauba wax composition will be heated to a deposition temperature of between 105°C to about 120°C for being ejected from the dispensing or print head.

[0035] Suitable antioxidants, for use in combination with the Carnauba wax composition described above, are, for example, BNX1010 (CAS 6683-19-8). The antioxidant typically comprises up to 1%, by weight, of the resulting Carnauba wax composition, more preferably the antioxidant typically comprises between 0.5% to 1%, by weight, of the resulting Carnauba wax composition, and most preferably the antioxidant comprises between 0.9% to 0.99%, by weight, of the resulting Carnauba wax composition.

[0036] For most applications, the Carnauba wax composition will comprise waxes in an approximate range of 0.5% to 99.5 percentage by weight.

[0037] While various embodiments of the present invention have been described in detail, it is apparent that various modifications and alterations of those embodiments will occur to and be readily apparent to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the appended claims. Further, the invention(s) described herein is capable of other embodiments and of being practiced or of being carried out in various other related ways. In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having," and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items while only the terms “consisting of and “consisting only of are to be construed in a limitative sense.

[0038] The foregoing description of the embodiments of the present disclosure has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the present disclosure be limited not by this detailed description, but rather by the claims appended hereto.

[0039] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the scope of the disclosure. Although operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.

Claims

Wherefore, we claim:

1 . A 3D printable wax material comprising:

Carnuba Wax, and at least one polymer, and the at least one polymer is between 5% and about 50%, by weight, of the 3D printable wax material and the Carnuba Wax is between 50% and about 90%.

2. The 3D printable wax material according to claim 1 , wherein the Carnauba wax comprises fatty acid esters, fatty alcohols, acids and hydrocarbons.

3. The 3D printable wax material according to claim 1 , wherein the Carnauba wax comprises 20% esterified fatty diols, 10% methoxylated or hydroxylated cinnamic acid, and 6% hydroxylated fatty acids.

4. The 3D printable wax material according to claim 1 , wherein the Carnauba has a melting point range between 80°C to 87°C and substantially insoluble in water and ethanol.

5. The 3D printable wax material according to claim 1 , wherein the Carnauba wax further comprises one or more of the following: an antioxidant, a viscosity control agent, a surfactant, a surface active agent and a plasticizer.

6. The 3D printable wax material according to claim 1 , wherein the Carnauba wax is blended with at least one other resin to from a stabilizer.

7. The 3D printable wax material according to claim 1 , wherein the 3D printable wax material has a freezing point temperature range of between 70°C and 85°C.

8. The 3D printable wax material according to claim 1 , wherein the 3D printable wax material has a freezing point temperature range of between 45°C and 100°C.

9. The 3D printable wax material according to claim 1 , wherein the 3D printable wax material has, at a temperature of about 120°C, a viscosity ranging from about 10 centi poise to 30 centipose.

10. The 3D printable wax material according to claim 1 , wherein the Carnauba wax comprises fatty acid esters, fatty alcohols, acids and hydrocarbons, the Carnauba wax further comprises one or more of the following: an antioxidant, a viscosity control agent, a surfactant, a surface active agent and a plasticizer;. the 3D printable wax material has a freezing point temperature range of between 45°C and 100°C; and at a temperature of about 120°C, the 3D printable wax material has a viscosity ranging from about 10 centi poise to 30 centipose.

11. A 3D printable wax material comprising:

Carnuba Wax, and a casting wax (Cerita 30-80 casting wax), and the casting wax is between 10% and about 20%, by weight, of the 3D printable wax material while the Carnuba Wax is between 80% and about 90%, by weight, of the 3D printable wax material.

12. The 3D printable wax material according to claim 11 , wherein the Carnauba wax comprises fatty acid esters, fatty alcohols, acids and hydrocarbons.

13. The 3D printable wax material according to claim 11, wherein the Carnauba wax comprises 20% esterified fatty diols, 10% methoxylated or hydroxylated cinnamic acid, and 6% hydroxylated fatty acids.

14. The 3D printable wax material according to claim 11 , wherein the Carnauba has a melting point range between 80°C to 87°C and substantially insoluble in water and ethanol.

15. The 3D printable wax material according to claim 11 , wherein the Carnauba wax further comprises one or more of the following: an antioxidant, a viscosity control agent, a surfactant, a surface active agent and a plasticizer.

16. The 3D printable wax material according to claim 11 , wherein the Carnauba wax is blended with at least one other resin to from a stabilizer.

17. The 3D printable wax material according to claim 11 , wherein the 3D printable wax material has a freezing point temperature range of between 70°C and 85°C.

18. The 3D printable wax material according to claim 11 , wherein the 3D printable wax material has a freezing point temperature range of between 45°C and 100°C.

19. The 3D printable wax material according to claim 11 , wherein the 3D printable wax material has, at a temperature of about 120°C, a viscosity ranging from about 10 centi poise to 30 centipose.

20. The 3D printable wax material according to claim 1 , wherein the Carnauba wax comprises fatty acid esters, fatty alcohols, acids and hydrocarbons, the Carnauba wax further comprises one or more of the following: an antioxidant, a viscosity control agent, a surfactant, a surface active agent and a plasticizer;. the 3D printable wax material has a freezing point temperature range of between 45°C and 100°C; and at a temperature of about 120°C, the 3D printable wax material has a viscosity ranging from about 10 centi poise to 30 centipose.