3D Inkjet Printing with Exothermic Cross-Linking
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Solution Overview
Problem
Conventional 3D printing technologies, such as Multi Jet Fusion, face limitations in producing light-colored materials due to energy absorption issues and insufficient mechanical strength, leading to molding failures or prolonged processing times.
Innovation Solution
A 3D inkjet printing method involving rapid spraying of a reactive fusion agent on preheated polymer powder, followed by near-infrared light to initiate cross-linking polymerization, achieving higher temperatures without excessive heat and enhancing mechanical strength through chemical cross-linking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional thermal catalysts with dark light-absorbing substances are used in Multi Jet Fusion technology, then energy absorption is improved, but the finished products become dark and light-colored materials cannot be used
Solution Approach 1:
The patent changes the chemical composition parameters of the fusion agent from conventional dark-colored thermal catalysts to a light-colored system comprising an isocyanate compound and a polyol compound. This parameter change allows light-colored pigments to be used in the polymer powder while maintaining effective energy absorption through the chemical reaction mechanism rather than light absorption by dark substances.
Solution Approach 2:
The patent replaces the conventional thermal catalyst system (which relies on dark light-absorbing substances to capture energy) with a chemical reaction system. The isocyanate and polyol compounds undergo exothermic cross-linking polymerization, substituting the energy absorption mechanism from physical light absorption to chemical energy release, thereby enabling light-colored material usage.
2Ease of manufacture
If conventional Multi Jet Fusion technology is used, then physical cross-linking of 3D molding materials is achieved, but mechanical strength is insufficient
Solution Approach 1:
The patent creates a composite chemical system by combining an isocyanate compound with a polyol compound as the fusion agent. This composite material approach enables dual functionality: the isocyanate provides cross-linking capability while the polyol contributes to mechanical strength through its molecular structure, achieving both ease of manufacture and high mechanical strength simultaneously.
Solution Approach 2:
The patent changes the chemical nature of the fusion agent from simple thermal catalysts to a reactive system involving isocyanate and polyol compounds. This parameter change transforms the cross-linking mechanism from purely physical to chemical cross-linking polymerization, significantly enhancing mechanical strength while maintaining manufacturing feasibility.
3Manufacturing precision
If conventional 3D laser sintering technology is used, then polymer powder can be melted and molded, but printing speed is slow
Solution Approach 1:
The patent applies preliminary action by pre-heating the polymer powder layer before applying the fusion agent. This pre-heating prepares the polymer powder for rapid chemical reaction and melting, enabling the exothermic cross-linking polymerization to proceed quickly and achieve high printing speed without sacrificing molding quality.
Solution Approach 2:
The patent utilizes phase transitions in the polymer powder, transitioning from solid powder to molten state through the combined effect of pre-heating and the exothermic chemical reaction. This controlled phase transition enables rapid melting and molding at high speed while maintaining precision through the chemical cross-linking mechanism.
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 method significantly improves printing speed and mechanical properties of finished products, achieving densities and precision comparable to mold injection molding while allowing for the use of light-colored pigments without affecting speed or quality.
Implementation Method 1
a heating step: applying a second composition to the surface of the first composition at the first temperature to proceed an exothermic cross-linking polymerization, so that the main body layer is heated to a second temperature to become a molten state
Implementation Method 2
rapidly spraying a reactive fusion agent on a print zone of the preheated polymer powder, and applying a near-infrared light heat source to initiate the cross-linking polymerization reaction
Implementation Method 3
release a large amount of heat to generate the synergistic effect, which causes the temperature to be higher than the melting point of the polymer powder, so the polymer powder can be melted and molded
Data Source
AI summary
The present invention provides a method for 3D inkjet printing, which comprises: a preheating step: an external heating source is used to heat a main body layer composed of a first composition to a first temperature, wherein the main body layer has a thickness of 10 μm to 500 μm and a unit density of 0.1 to 1.0 g/cm3, and the first temperature is less than the melting point of the first composition; a heating step: a second composition is applied to the surface of the first composition at the first temperature of the composite to proceed an exothermic cross-linking polymerization, so that the main body layer is heated to a second temperature to become a molten state; and a cooling step: the main body layer in the molten state is cooled down and solidified to form.