3D Hot-Melt Printing Near-Infrared Preheating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional 3D melt printing processes face challenges with low productivity and surface quality due to volume heating methods, which result in delayed re-solidification, uneven surfaces, and high energy consumption.
Innovation Solution
The process focuses on pre-heating only the areas of the product that need to be processed using near Infrared (NIR) radiation with a low penetration depth and high power density, above 200 kW/m², and selectively heating above the sintering or melting temperature with NIR radiation, allowing for precise temperature control and reduced thermal load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional heating methods (volume heating) are used to preheat the worktable or partial product, then the entire material layer can be heated uniformly, but this causes delayed resolidification, reduced productivity, and high energy consumption
Solution Approach 1:
The patent applies local quality by transitioning from uniform volume heating to selective surface heating only at the worktable level where material processing occurs. The heating device is positioned to heat only the immediate working area, allowing other areas to remain at lower temperatures, thereby reducing overall energy consumption and improving productivity by enabling faster processing cycles.
Solution Approach 2:
The heating process is segmented into two distinct stages: a first heating stage that preheats only the worktable surface to a first temperature, and a second heating stage that heats specific points above the sintering temperature. This segmentation allows the system to minimize energy consumption while maintaining processing efficiency.
2Temperature
If conventional heating methods are used for preheating, then the worktable can be heated, but this causes potentially quality-reducing irregularities on the product surface
Solution Approach 1:
The patent applies local quality by transitioning from uniform volume heating to selective surface heating only at the worktable level where material processing occurs. The heating device is positioned to heat only the immediate working area, allowing other areas to remain at lower temperatures, thereby reducing overall energy consumption and improving productivity by enabling faster processing cycles.
Solution Approach 2:
The patent replaces conventional mechanical/conductive heating systems with a radiation-based heating system. The heating device emits radiation that selectively heats the worktable surface without causing the excessive heat transfer that leads to surface irregularities in conventional methods.
3Temperature
If conventional heating methods are used for preheating, then the material layer can be heated, but this results in high energy consumption
Solution Approach 1:
The patent applies local quality by transitioning from uniform volume heating to selective surface heating only at the worktable level where material processing occurs. The heating device is positioned to heat only the immediate working area, allowing other areas to remain at lower temperatures, thereby reducing overall energy consumption and improving productivity by enabling faster processing cycles.
Solution Approach 2:
The heating process is segmented into two distinct stages: a first heating stage that preheats only the worktable surface to a first temperature, and a second heating stage that heats specific points above the sintering temperature. This segmentation allows the system to minimize energy consumption while maintaining processing efficiency.
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 significantly reduces energy consumption, minimizes unwanted softening of non-sintered material, eliminates the need for extensive cleaning, and enhances the efficiency of reusable materials, while enabling precise control over temperature differences and color design in the final product.
Implementation Method 1
preheating of the existing partial product to a temperature close to the sintering or melting temperature is effected by an additional heating device... using radiation with a relatively shallow penetration depth, namely near-infrared radiation (also known as NIR radiation)
Implementation Method 2
utilizing the absorption-enhancing effect... the heating above the melting temperature of the material is caused by utilizing the absorption-enhancing effect
Implementation Method 3
selective local heating of previously applied material layers... typically achieved using a coordinate-controlled laser that moves across the material layers
Implementation Method 4
selectively heating above the sintering or melting temperature... heating above the melting temperature of the material is caused by utilizing the absorption-enhancing effect
Implementation Method 5
an inkjet printer is used to apply a substance that increases the absorption rate of the most recently applied layer of material in point by point
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a 3D hot-melt printing process for producing a three-dimensional product (P) substantially from a polymer powder or polymer filaments, the product being built up in layers by application of polymer plies of powder or filament onto a respectively previously produced ply and selective local heating of predetermined points on the ply by means of a sintering or melting temperature of the powder or of the filaments and sintering or melting of the melted points with the underlying layer. The polymer ply which is in each case newly applied and optionally at least one underlying layer is preheated by planar or travelling irradiation of short- or medium-wave IR radiation to a temperature with a predetermined difference for sintering or melting temperature. The preheating of at least the newly applied polymer ply and/or the local heating is carried out by means of the sintering or melting temperature by means of near IR radiation, in particular with a radiation density maximum in the wavelength range between 0.77 and 1.2 pm and with high power density above 200 KW/m2.