Powder Material Surface Tension for MJF Fluid Spreading
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Solution Overview
Problem
Existing methods for producing three-dimensional objects using the MJF mode face limitations with resins having low or high wettability for aqueous solvents, leading to uneven energy absorption and reduced strength or dimensional accuracy due to inadequate spreading of bonding and release fluids.
Innovation Solution
A powder material with organic resin layers having a surface tension of 30 mN/m to 45 mN/m is used, allowing for even distribution and spreading of bonding and release fluids, enabling the use of various resins with different wettability levels and improving the fusion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If resin particles with low wettability for aqueous solvents are used, then the resin can be used in the MJF mode, but the bonding fluid does not sufficiently spread, resulting in uneven energy absorbent distribution and low strength
Solution Approach 1:
A surfactant is introduced as an intermediary substance between the bonding fluid and resin particles with low wettability. The surfactant reduces the surface tension of the bonding fluid, enabling it to spread uniformly over the resin particle surfaces even when the resin has inherently low wettability for aqueous solvents. This ensures even distribution of the energy absorbent and eliminates the uneven heating that would otherwise occur.
Solution Approach 2:
The surface tension parameter of the bonding fluid is modified by adding a surfactant. This parameter change allows the bonding fluid to wet and spread over resin particles that would otherwise be incompatible with aqueous-based fluids, thereby enabling the use of resins with low wettability while maintaining uniform fluid distribution and high object strength.
2Manufacturing precision
If resin particles with high wettability for aqueous solvents are used, then the bonding fluid spreads well, but the fluid spreads excessively, resulting in low dimensional accuracy
Solution Approach 1:
The surface tension parameter of the bonding fluid is adjusted downward by adding a surfactant. This parameter modification creates a balance in the spreading behavior: the fluid has sufficient wetting capability to cover the resin particle surfaces uniformly, but the spread is controlled and does not exceed the boundaries of the applied region, thereby maintaining dimensional accuracy.
3Adaptability or versatility
If polyamide 12 is used as the resin, then appropriate wettability for bonding fluid is achieved, but the resin selection is limited and other resins cannot be used
Solution Approach 1:
The bonding fluid system is made universal by incorporating a surfactant that can accommodate resins with varying wettability characteristics. Instead of requiring each resin type to have specific wettability properties, the surfactant-modified bonding fluid can effectively wet and spread over diverse resin surfaces, enabling the use of multiple resin types (polypropylene, polyethylene, polystyrene, etc.) while maintaining consistent and reliable wettability across all resin varieties.
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
This approach results in three-dimensional objects with high strength and dimensional accuracy, as the organic resin layers ensure even energy absorption and bonding, overcoming the limitations of previous methods.
Implementation Method 1
the energy absorbent in the curing region absorbs the energy to generate heat
Implementation Method 2
an organic resin layer which includes an organic resin having a surface tension of 30 mN/m to 45 mN/m is disposed around the resin particle
Data Source
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AI summary
The present invention addresses the problem of providing a powder material that has good wettability with respect to an aqueous solvent and that can be applied to a method for producing a three-dimensional molded object in which a bonding fluid and a peeling fluid are applied. In order to solve the abovementioned problem, a powder material according to the present invention is used in a method for a producing a three-dimensional molded object that includes formation of a thin layer containing the powder material, application of a bonding fluid containing an aqueous solvent and an energy-absorbing agent to the thin layer, and irradiation of the thin layer with energy. The powder material contains molding particles comprising: resin particles containing a thermoplastic resin; and an organic resin layer that is arranged around the resin particles and that contains an organic resin having a surface tension of 30-45 mN/m.