Method for manufacturing and using a composite fluid
By transforming liquids into foaming liquids with a multimodal bubble system, the method addresses the challenge of supporting overhangs in 3D printing, achieving stable and accurate printing by counteracting gravitational forces and maintaining object shape.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- RAYO 3D BIOTECH OY
- Filing Date
- 2023-06-22
- Publication Date
- 2026-05-19
AI Technical Summary
Existing 3D printing technologies face challenges in supporting overhangs due to gravitational forces, leading to deformation and inaccuracy of printed objects, especially when using Newtonian and non-Newtonian liquids with high-density filler particles, as conventional support materials fail to counteract gravity effectively.
A method to transform Newtonian or non-Newtonian liquids into foaming liquids with a multimodal gas bubble system, stabilized by crosslinking compounds and nanofillers, which exhibit plastic deformation and counteract buoyancy effects, allowing stable support for overhangs during 3D printing.
The foaming liquid with a multimodal bubble system provides effective support against gravity, maintaining overhangs and ensuring accurate 3D printing by transitioning from fluid to semi-solid states, enhancing the stability and smoothness of printed objects.
Smart Images
Figure 2026516080000001_ABST
Abstract
Description
Technical Field
[0001] (Field) The present disclosure relates to the production of a bubbly liquid having complex fluid characteristics for use in additive manufacturing (or 3D printing).
Background Art
[0002] (Background) In the production of 3D printed objects (or objects) having diverse shapes, there can be shapes or parts of shapes such as overhangs that cannot be balanced by the body of the printable object and thus can be a fatal overhang where the printing material can collapse due to gravity. There are various attempts that can be used to overcome this problem, such as printing the material in a support bath and multi-channel plotting by co-extruding a temporary support material together with the main printing material. When a support path is used, Newtonian and non-Newtonian liquids and gels have physical properties that cause the movement of the support material and the elongation of the printable material under shear forces caused by the movement of the injection head of a 3D printing device. This causes deformation and inaccuracy of the printable object. Further, the liquid support material, despite its possible high viscosity, may not sufficiently support the printable material against the effect of gravity when, for example, the density of the printable material is high due to heavy filler particles.
[0003] It is a preferred characteristic that the support material has a liquid-like continuous phase through which the printing head moves, but at the same time, it is necessary that the continuous fluid phase exhibits plastic behavior when a shear force is applied to the support material by the movement of the printing head. [Overview of the project]
[0004] (Brief explanation) The scope of protection required for the various embodiments of the present invention is presented by the independent claims. Any exemplary embodiments and features described herein that do not fall within the scope of the independent claims should be interpreted as useful examples for understanding the various embodiments of the present invention.
[0005] According to a first aspect, there exists a method and system for producing a foaming liquid material in which a Newtonian or non-Newtonian liquid material is transformed (or changed) into a foaming liquid material having the plastic deformation properties of a composite fluid by a jamming transition. The resulting foaming liquid material can be used as a support material for 3D printing in a 3D printing system.
[0006] In an exemplary embodiment according to the first aspect, the foamy liquid material is formed by the generation of primary bubbles in the liquid material. This can be achieved, for example, by adding a surfactant to a Newtonian liquid and forming primary bubbles in the liquid by physical means such as an aerator or shaking to have a non-Newtonian liquid.
[0007] In an exemplary embodiment according to the first aspect, primary bubbles are stabilized with a crosslinking-promoting (or enhancing) compound. For example, primary bubbles can be stabilized by adding free radicals, such as a compound, or other molecular compounds or nanofillers to a continuous liquid phase, followed by shaking to form secondary bubbles, thus creating a composite fluid of foamy liquid, and further by absorbing material from the surrounding medium.
[0008] Optionally, in exemplary embodiments according to the first aspect, tertiary bubbles are generated in the stabilized foamy liquid material by a chemical reaction or by physical means of injecting a gas into the foamy liquid material, and the creation of the foamy liquid material includes a multimodal (or multi-modal, composite, or multi-faceted) gas bubble system such that it has plastic deformation when a shear force is applied.
[0009] In an exemplary embodiment according to the first aspect, the foamy liquid material thus has a system of gas bubbles (or gas bubbles, gas bubbles or gas bubbles) of one or more different gas compositions.
[0010] In an exemplary embodiment according to the first aspect, the gas bubbles can reduce the buoyancy effect of the continuous liquid phase and the surface tension of the gas bubbles can counteract the effect of gravity.
[0011] In an exemplary embodiment according to the first aspect, the multimodal bubble system can also reduce the influence of Archimedes' principle and hold additional printing material in place vertically (y-direction).
[0012] In an exemplary embodiment according to the first aspect, the stabilized continuous liquid phase of the foaming liquid traps gas bubbles within the foaming liquid, preventing the collapse and coalescence (or adhesion) of the gas bubbles.
[0013] In an exemplary embodiment according to the first aspect, a foaming liquid having primary and secondary bubbles, and a subsequent jamming transition, influences the firmness and stiffness of the foaming liquid so that it can support additional material in the foaming liquid so that it is maintained in a desired xyz position and volume configuration.
[0014] In an exemplary embodiment according to the first aspect, additional materials in a foamy liquid can transition their state from a fluid and fluid-like state to a semi-solid and a solid.
[0015] In exemplary embodiments according to the first aspect, the viscosity and mass transition state of the foaming liquid can be altered by primary bubbles, secondary bubbles and optional tertiary bubbles in the foaming liquid, coexisting chemical reactions, and the addition of nanoparticles or molecules for emulsions, suspensions, or colloidal systems. [Brief explanation of the drawing]
[0016] [Figure 1] Figure 1 shows a foaming liquid system having primary bubbles and printable material. [Figure 2] Figure 2 shows a foamy liquid system containing primary and secondary bubbles and a printable material. [Figure 3] Figures 3A and 3B illustrate the collapse and runoff of additional material due to gravity and the effect of a foamy liquid resisting the effects of gravity. [Figure 4] Figure 4 shows the static flow of liquids of the same composition without bubbles. [Modes for carrying out the invention]
[0017] (Detailed explanation) The following embodiments are illustrative. While this specification may refer to “an,” “one,” or “several” embodiments in several places, this does not necessarily mean that each reference is made to the same embodiment, or that certain features are limited to a single embodiment. A single feature from different embodiments may be combined to provide other embodiments.
[0018] Non-Newtonian liquids are characterized by their viscosity, which changes with motion. Most non-Newtonian liquids have a molecular chain structure and are also composite fluids. Composite fluids are mixtures having two or more phases, such as solid-liquid (suspension), solid-gas, liquid-gas (foam (or foamy substance or foam)), or liquid-liquid (emulsion). The mechanical response of composite fluids involves a transition between solid-like behavior and fluid-like behavior, including plastic deformation. Composite fluids that exhibit plastic deformation under shear can, for example, be cut. This type of material is called a Bingham plastic.
[0019] Foaming liquids, also referred to as foaming liquid materials, contain a continuous liquid phase and approximately 50% gas bubbles. With higher gas bubble volume loads, the material becomes foamy. Bubbles modify (or alter) the rheology of the liquid by resisting deformation, and the behavior of the liquid is influenced by the properties of the continuous liquid phase and the size-bubble-volume fraction of the bubbles. The surface tension of the bubbles balances the outward force of air pressure with the weight of the substance in the foaming liquid due to Laplace pressure. Bubbles form in a liquid when the amount of dissolved gas exceeds the limit of its solubility in the liquid, and the gas molecules join together in aggregates (or aggregates) that form gas bubbles. Unless the viscosity and plasticity of the continuous liquid phase trap the bubbles and prevent them from floating, the gas bubbles float due to their low density, thus stabilizing the foaming liquid. Furthermore, the trapping of gas bubbles in a liquid is also influenced by friction, known as drag or fluid resistance.
[0020] Archimedes' principle enables the buoyancy (or flotation: buoyancy) of a floating object immersed in a liquid when additional material of the object is placed in the liquid. The buoyancy effect on the material or object is equal to the weight of the displaced liquid. However, if the liquid is filled with gas bubbles, its weight is substantially smaller compared to the liquid without gas bubbles, and the buoyancy effect becomes smaller. The balance (or equilibrium: balance) of the buoyancy effect, the effect of gravity, and the surface tension of the gas bubbles holds the additional material and the object in a stable position within the liquid. Also, the buoyancy effect can be explained by the collision of water molecules with the floating object rather than the weight of the displaced liquid. Also in this case, gas bubbles will reduce the number of water molecules and there will be less floating in the bubbly liquid. Also, it is worth noting to emphasize the effect of surface tension, that is, the effect of the density difference between the liquid phase and the gas phase, which is typically effective on the liquid surface that floats a light object. Also, when gas bubbles are present, the density difference also exists inside the liquid.
[0021] Gas bubbles (or gas bubbles or gas cells: gas bubble) can be generated using physical means such as the use of an aerator, shaking of the liquid, and also by chemical reactions in the liquid material to generate gas. The continuous liquid phase is typically made from a Newtonian liquid of water, and by adding a surfactant such as soap to the water, the surface tension of the water is lowered and foaming is increased. Normal foam is an unstable system, and the foam disappears over time. If the surfactant simultaneously increases the viscosity of the water and makes the liquid into a complex fluid type, the bubble collapse time may be extended or the bubbles may even be trapped in the continuous liquid phase. Compounds that lower the surface tension of water and enhance (or enhance) the formation of bubbles are, for example, methyl cellulose (C6H7O2(OH) x (OCH3) y ), hydroxypropyl methyl cellulose (C 56 H 108 O 30 ) or chitin (C8H 13 O5N) n)contains. Methylcellulose hydrogels (or hydrogels) can be aerated (or aerated) by aerator or shaking. For initial stabilization of the methylcellulose hydrogel to capture air bubbles, free radical-forming compounds in the methylcellulose aqueous liquid enhance the affinity of the methylcellulose polymers to react with each other for crosslinking. An example of a cross-linking enhancing compound is 4,4'-azobis(4-cyanopentanoic acid), which spontaneously forms small amounts of hydroxyl radicals in the liquid at RTP. Another example of a cross-linking enhancing compound is silyl glyoxylate. Other crosslinking agents for crosslinking methylcellulose include epichlorohydrins, aldehyde reagents, urea derivatives, and polyfunctional carboxylic acids such as citrate. In the crosslinking chain, copolymerization with the vinyl groups of methylcellulose occurs in the presence of water, and the hydrogel begins to form. Air bubbles in a slightly crosslinked hydrogel can be called primary bubbles.
[0022] Figure 1 shows an example of such primary bubbles 120 in a foamy liquid material 105 produced for use as a support material for 3D printing. The primary bubbles 120 may be, for example, 0.1 to 1.0 mm in diameter (Figure 1). The amount of methylcellulose can be 1 to 20% by weight of water, preferably 5% by weight. The surface tension 125 of the air bubbles and the density difference between gas and liquid balance the outward force of the air pressure, supporting the printable material extruded from the print head 110 used for 3D printing in the 3D printing system 100, and forming a printable object 115 from run-off due to gravity. Non-Newtonian hydrogels can retain air bubbles in the gel for longer than Newtonian hydrogels, but water hydrogels do not completely capture bubbles, and if the hydrogel is stored or used as a support material for 3D printing, the bubbles will disappear over time. Thus, less than one second after the injection of the resin material before polymerization begins, the overhang will already collapse due to the force of gravity, as shown in Figure 2. In Figure 2, there is a chart where the y-axis represents the outflow (mm) 205 and the x-axis represents the time from the start of printing 200. Printing can be performed using a 3D printing system such as Printing System 3D. Generally, a 3D printing system includes a print head configured to inject the printing material into a support material which may be a bubbly liquid. Printing can be controlled by a control unit coupled to the print head using any suitable mechanism for coupling. It should also be noted that printing control can be performed, at least in part, using computer program instructions. In Figure 2, the force of gravity 230 affects the overhang of the object being printed. In Scenario 240, the printed object 210 has an overhang 215. In this scenario, there are no gas bubbles in the hydrogel used as the support material, and as a result, there is an outflow of the overhang (or protrusion or projection) 215. In Scenario 250, an object 220 is printed, which has an overhang 225. In this scenario, a hydrogel support material having primary, secondary, and tertiary gas bubbles provides support for the overhang 225.To stabilize the bubble liquid to capture air bubbles and increase its viscosity, additional compounds such as cellulose nanocrystals (CNC) or other polysaccharides such as sucrose or fructose can be added to the hydrogel. When sucrose is used for bubble stabilization, the sugar content can be 10 to 150% by weight of the water, preferably 80% by weight. Further agitation of the hydrogel with the additional compound forms secondary air bubbles in the hydrogel, along with an increase in viscosity and, of course, a gelation transition to the complex fluid. Other molecular compounds and nano-sized fillers such as graphene, silica, zirconia, alumina can be added to the bubbly liquid of the hydrogel to increase the viscosity and cause a gelation transition.
[0023] The composite fluid properties and homogeneity of hydrogels can be enhanced by tertiary gas bubbles, which can be nitrogen gas (N2) containing bubbles with a diameter of, for example, 0.01–0.1 mm. The effect of secondary and tertiary gas bubbles on the static flow of 300 10 ml hydrogel droplets on a glass plate is shown by measuring the diffusion (or spreading) of the hydrogel droplets at room temperature and pressure (RTP) for 20 minutes (Figure 3A) in the examples shown in Figures 3A and 3B. Groups A–D with the same composition of methylcellulose and sucrose are as follows: A: no primary, secondary, or tertiary bubbles; B: with tertiary bubbles; C: with primary and secondary bubbles; D: with primary, secondary, and tertiary bubbles. The arrows schematically show the width of the droplets after 20 minutes. Figure 3B shows that the diffusion of hydrogels with the same composition but different gas bubble structures behaves differently in their fluid properties. A third gas bubble source, which may function as a protective gas such as N2 or argon (Ar) to enhance free radical polymerization by eliminating the oxygen inhibitory effect of free radical polymerization of the printable resin material due to the oxygen diffused into the hydrogel, is a chemical reaction in the hydrogel or the injection of gas into the hydrogel. The tertiary gas bubbles increase the homogeneity of the hydrogel and fill larger primary air bubbles (or air bubbles or air bubbles). This is shown in Figure 4, where tertiary bubbles 425 are present in a support material 405. This support material is used with a printing system 400 in which a print head 410 is present, and the print head 410 injects the printing material into the support material 405 to produce a 3D printed object 415 including overhangs. The support material 405 also contains primary and secondary bubbles 420. The printing system 400 in this exemplary embodiment may further include a control unit configured to control the movement of the print head 410 and the injection of the printing material. This control can be achieved using appropriate mechanical structures and software to control the 3D printing process. Having tertiary bubbles 405 improves the surface smoothness of the printable object 415 if the hydrogel is used as a support material 405 for the 3D printed object 415 having overhangs.The bubble system of the composite fluid, possessing viscosity (or consistency) and plastic deformation, is used as a printing material and provides support for resin materials 3D printed on hydrogels used as support material 405, eliminating material outflow due to gravity, the effect of which is shown in Figure 2.
[0024] Furthermore, hydrogels other than methylcellulose can also be adjusted to become composite fluids by adding sucrose molecules or several other molecules. Nonionic polyacrylamide (PAM)((C3H5NO) n )-Water hydrogel (PAH), cellulose microfibrils, cellulose nanocrystals, potassium salts, chitosan, alginates, polyvinyl alcohol, starch, gelatin water hydrogel can be used in 3D printing support materials or bio-ink applications in a similar manner to sucrose. Biodegradable hydrogels are naturally based hydrogels such as polysaccharides (e.g., chitosan), starch, gelatin, alginates, and proteins (e.g., collagen), or synthetic hydrogels such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA), and polypropylene fumarate (PPF).
[0025] Composite foaming liquids can be used in 3D printing, for example, as support materials, but they can also be used in fields where foaming liquid compounds and nanofillers can adsorb and remove undesirable inorganic substances such as metals, heavy metals, and metalloids, as well as organic substances such as dyes, pesticides, or trace contaminants from water or soil, or in the food industry to adjust the viscosity of food. In these types of applications, a liquid containing graphene, cationic polymers, or aluminum sulfate is poured or applied (or coated) to the substance to be cleaned, and a chemical reaction occurs, using sunlight irradiation or a specially designed radiation device (or radiator device), to produce a hydrogel that stabilizes free radicals. Before stabilization occurs, contaminants are adsorbed by graphene, cationic polymers, or aluminum sulfate and can be removed by removing the composite fluid. In water washing, controlling the buoyancy effect by primary, secondary, and tertiary bubbles, and having space for contaminants in the three-dimensional foam structure, enhances the removal of undesirable substances.
Claims
1. A method for manufacturing a foamy liquid material suitable for use as a support material in a 3D printing system, To generate primary bubbles in a liquid material; Stabilizing primary bubbles with crosslinking-promoting compounds; To generate secondary bubbles in a liquid material; and Using a liquid material containing primary and secondary bubbles as a support material for printing 3D objects. Includes, The manufacturing method wherein the liquid material includes a bubble system comprising at least primary bubbles and secondary bubbles.
2. The method for producing a liquid according to claim 1, further comprising inducing a jamming transition in the liquid.
3. The ability to generate primary bubbles is Adding surfactants to liquid materials; and Shake the liquid material or use an aerator. Includes, The manufacturing method according to claim 1 or 2, wherein the liquid material is a Newtonian or non-Newtonian liquid material.
4. A manufacturing method according to any one of claims 1 to 3, wherein stabilizing the primary bubbles includes adding free radicals, molecular compounds, or nanofillers to the continuous liquid phase of the liquid material.
5. The method according to claim 4, wherein generating secondary bubbles includes shaking.
6. The manufacturing method according to any one of claims 1 to 5, further comprising generating tertiary bubbles, wherein the tertiary bubbles are generated by causing a chemical reaction or by injecting a gas into a liquid material.
7. The manufacturing method according to any one of claims 1 to 6, wherein tertiary bubbles are included in the bubble system, and the bubbles in the bubble system have one or more different gas compositions.
8. The manufacturing method according to claim 7, wherein the primary bubbles contain air and / or the tertiary bubbles contain nitrogen gas.
9. The manufacturing method according to any one of claims 1 to 8, wherein the liquid material is a hydrogel.
10. A system for 3D printing, The 3D printing system further comprises a print head configured to inject a printing material to form a 3D printed object, the system further comprises controlling the 3D printing by a control unit, and the system is configured to inject the printing material into a support material produced using a manufacturing method according to any one of claims 1 to 9.