Solvent-Free Particle Composition for Stable 3D-Printed Green Bodies
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Solution Overview
Problem
Existing additive manufacturing (AM) techniques using curable compositions with shear-thickening properties lead to equipment malfunction, increased production time and cost, agglomeration issues, poor wetting of particles, stability problems, and result in green bodies and printed articles with poor optical transparency, dimensional instability, and reduced strength.
Innovation Solution
Compositions comprising high loading (65% by weight or more) of particles with good stability and wetting, substantially solvent-free, and printable viscosities (100 mPa-s to 7,000 mPa-s) are used, along with a photo-initiator, curing agent, and dispersant to produce optically transparent green bodies and printed articles with improved dimensional stability and mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If curable compositions with shear-thickening properties are used in additive manufacturing, then the compositions can provide printable viscosity, but they cause equipment malfunction and increase production time
Solution Approach 1:
The patent changes the rheological parameters of the curable composition by formulating it to be Newtonian rather than shear-thickening, while maintaining appropriate viscosity for printing. This eliminates the equipment malfunction and production delays caused by shear-thickening behavior while preserving the ability to deposit material in predetermined patterns.
Solution Approach 2:
The patent removes the shear-thickening property from the curable composition formulation. By extracting this problematic characteristic while retaining the essential printing capabilities and curable properties, the invention eliminates equipment malfunction and improves production efficiency without sacrificing the core functionality.
2Strength
If curable compositions comprising particles are used, then the compositions can provide structural integrity, but they exhibit agglomeration issues and poor wetting
Solution Approach 1:
The patent introduces a dispersant as an intermediary substance in the curable composition formulation. This dispersant acts as a mediator between the particles and the continuous phase, preventing agglomeration and improving wetting of particles while maintaining the structural integrity provided by the particle loading.
Solution Approach 2:
The patent modifies the surface chemistry parameters of the particles or the continuous phase to improve wetting characteristics. By changing these parameters, the composition achieves better particle dispersion and wetting while maintaining the structural benefits of high particle loading.
3Ease of operation
If solvents and rheology modifiers are added to curable compositions, then the compositions can achieve printable viscosity, but they impair curing speed and reduce quality
Solution Approach 1:
The patent removes solvents and rheology modifiers from the curable composition formulation. By extracting these additives, the invention eliminates the impairment of curing speed and quality issues while maintaining printable viscosity through alternative means such as optimized particle packing and binder selection.
Solution Approach 2:
The patent formulates the curable composition to be self-regulating in terms of viscosity and flow characteristics without requiring external additives. The composition maintains appropriate printing properties through its inherent formulation, eliminating the need for solvents and rheology modifiers that would otherwise be required to achieve printable viscosity.
4Quantity of substance
If high loading of particles is used in curable compositions, then the compositions can reduce material costs, but they exhibit limited stability before settling
Solution Approach 1:
The patent introduces a dispersant as an intermediary that stabilizes high particle loading compositions. This dispersant prevents settling and maintains composition stability while allowing high particle loading that reduces material costs. The dispersant acts as a mediator that keeps particles uniformly distributed without aggregation.
Solution Approach 2:
The patent modifies the formulation parameters of the curable composition to achieve stable high particle loading. By changing parameters such as binder type, particle surface chemistry, and continuous phase properties, the composition maintains stability before settling while achieving the desired high particle loading for cost reduction.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The compositions reduce production time and cost, minimize shear-thickening behavior, enhance processing speeds, and improve the quality of green bodies and printed articles by increasing optical transparency, dimensional stability, and mechanical strength.
Implementation Method 1
The composition can comprise a photo-initiator. The composition can comprise a curing agent.
Data Source
AI summary
A composition can comprise particles comprising 5% by weight (wt %) or more, a photo-initiator, a curing agent, a dispersant, and an organic binder. The composition can be substantially solvent-free. In some embodiments, particles comprise 65 wt % or more. In some embodiments, the curing agent comprises dipropylene-glycol diacrylate. In some embodiments, the dispersant comprises a phosphate ester. In some embodiments, the organic binder comprises isobornyl methacrylate. In some embodiments, the composition comprises a viscosity from about 100 milliPascal-seconds to about 7,000 milliPascal-seconds. Methods of making a green body can comprise creating a composition, printing the green body using the composition, and curing the green body. Method of making a printed article can comprise creating a composition, printing a green body using the composition, curing the green body, heating the green body to remove the organic binder to form a porous article, and sintering the porous article to form the printed article.