Polyamide 3D Printing Powder Composition for Multi-Run Recyclability
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Solution Overview
Problem
Existing polyamide powders used in 3D printing face issues with recyclability and degradation of mechanical properties during multiple runs, requiring significant adjustments to sintering device parameters and leading to unsatisfactory mechanical properties in the resulting parts.
Innovation Solution
Incorporating a specific thioether antioxidant, such as pentaerythritol tetrakis (3-dodecylthio propionate), into the polyamide powder to stabilize color and increase inherent viscosity, allowing for multiple recyclings while maintaining acceptable mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If polyamide powder is recycled multiple times in 3D printing processes, then powder utilization efficiency improves and material waste decreases, but the mechanical properties of manufactured parts deteriorate and sintering parameters require drastic adjustments
Solution Approach 1:
The patent modifies the chemical composition parameters of polyamide powder by incorporating specific antioxidants (phenolic and thioether types) and chain extenders. These compositional changes enable the powder to maintain its mechanical properties through multiple recycling cycles (at least 5 times) without requiring drastic parameter adjustments in the sintering process
Solution Approach 2:
The patent introduces antioxidant additives as intermediary substances that mediate between the polyamide powder and degradation mechanisms. These antioxidants (particularly thioether antioxidants like pentaerythritol tetrakis(3-dodecylthio propionate)) protect the powder from oxidative degradation during recycling, allowing maintenance of mechanical properties through multiple reuse cycles
2Reliability
If radiation power is increased to compensate for powder degradation in successive runs, then sintering effectiveness is maintained, but energy consumption increases and process efficiency decreases
Solution Approach 1:
By changing the chemical composition parameters of the powder (adding antioxidants and chain extenders), the patent maintains consistent sintering behavior across multiple recycling cycles. This eliminates the need to increase radiation power in successive runs, thereby maintaining energy efficiency while ensuring reliable sintering effectiveness
3Strength
If polyamide powder with high molecular mass is used to ensure good mechanical properties, then part strength improves, but melting energy requirement increases and inter-grain coalescence becomes insufficient
Solution Approach 1:
The patent optimizes the molecular mass parameters of polyamide powder to a specific range (inherent viscosity 1.2-2.0 dL/g) and compensates for mechanical property requirements through controlled chain extension during sintering. This balanced approach reduces melting energy requirements while ensuring sufficient inter-grain coalescence and acceptable mechanical properties in final parts
4Use of energy by moving object
If polyamide powder with low molecular mass is used to reduce melting energy and improve coalescence, then sintering efficiency improves, but the resulting parts exhibit insufficient mechanical properties
Solution Approach 1:
The patent introduces chain extenders as intermediary substances that act during the sintering process to increase the molecular mass of polyamide chains. This allows the use of lower molecular mass powder (reducing melting energy) while achieving sufficient mechanical properties through in-process chain extension
Solution Approach 2:
The patent utilizes controlled changes in molecular mass parameters during the sintering process itself, rather than relying solely on the initial powder molecular mass. This dynamic parameter change enables energy-efficient sintering while achieving required mechanical properties
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 thioether antioxidant stabilizes the polyamide powder's properties, enabling at least 3-10 times recyclability with reproducible mechanical properties, including tensile modulus and elongation at break, and reduces yellowing during aging.
Implementation Method 1
incorporating a specific thioether antioxidant, such as pentaerythritol tetrakis (3-dodecylthio propionate), into the polyamide powder to stabilize color and increase inherent viscosity
Implementation Method 2
The agglomeration of powders by melting (hereinafter 'sintering') is caused by radiation, such as, for example, a laser beam (laser sintering)
Implementation Method 3
an absorber is deposited on the layer (for example, using liquid ink in the 'inkjet process') before the layer is exposed to electromagnetic radiation (for example, infrared), which causes the areas containing the absorber to melt
Data Source
AI summary
The present invention concerns a powder for 3D printing, made from thermoplastic polymer, characterised in that it contains at least 0.1% by weight of at least one thioether antioxidant, with respect to the total weight of powder. The present invention also concerns a method for stabilising the colour of a polymer-based powder in a 3D printing process, in which at least 0.1% by weight of at least one thioether antioxidant is incorporated, with respect to the total weight of powder.