Regulated Polyamide Powder for Laser Sintering Recyclability
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Solution Overview
Problem
Existing layer-by-layer processes using polyamide powders face issues with post-condensation and increased solution viscosity, leading to reduced recyclability and impaired mechanical properties, resulting in excessive discard of recycling powder and compromised component quality.
Innovation Solution
A mixture of diacid-regulated and diamine-regulated polyamide or copolyamide powders is used, which maintains stable solution viscosity and prevents post-condensation, allowing for repeated use without significant virgin powder addition, thereby enhancing recyclability and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polyamide powder is used in layer-by-layer processes, then the powder can be selectively melted and sintered to form components, but post-condensation occurs under high temperature conditions leading to increased solution viscosity and reduced recyclability
Solution Approach 1:
The patent changes the chemical parameters of the polyamide powder by introducing difunctional regulators (diacids or diamines) during polymerization. This regulation controls the end groups of the polymer chains, preventing post-condensation reactions under laser sintering conditions. The regulated powder maintains stable solution viscosity and can be reused multiple times without significant degradation, directly resolving the contradiction between recyclability and post-condensation.
Solution Approach 2:
The patent creates a composite powder system by combining regulated polyamide with controlled amounts of virgin powder in each recycling cycle. This composite approach ensures that the regulated polyamide maintains its anti-post-condensation properties while the virgin powder compensates for any minor property changes, thereby maintaining high recyclability and component quality over multiple production cycles.
2Loss of substance
If recycling powder is reused in layer-by-layer processes, then material waste is reduced, but mechanical properties of the components deteriorate
Solution Approach 1:
The patent modifies the chemical structure of the polyamide by incorporating difunctional regulators during synthesis. This parameter change ensures that the regulated polyamide maintains stable end groups that prevent degradation during laser sintering. As a result, recycling powder can be reused multiple times without significant loss of mechanical properties, resolving the contradiction between material waste reduction and component strength.
Solution Approach 2:
The patent implements a feedback mechanism by monitoring and controlling the ratio of recycling powder to virgin powder in each production cycle. The regulated polyamide provides stable performance that feedback loops can rely upon, allowing optimized mixing ratios that maximize recyclability while maintaining mechanical properties. The system adapts the virgin powder addition based on the performance characteristics of the regulated polyamide.
3Manufacturing precision
If large amounts of virgin powder are mixed with recycling powder, then component quality is maintained, but production costs increase and productivity decreases
Solution Approach 1:
The patent changes the chemical parameters of the polyamide powder through regulation with diacids or diamines. This creates a powder with stable end groups that prevent post-condensation and maintain mechanical properties over multiple recycling cycles. Consequently, much smaller amounts of virgin powder are needed in each cycle to maintain component quality, directly improving production efficiency while preserving manufacturing precision.
Solution Approach 2:
The patent enables effective recovery and reuse of recycling powder through the use of regulated polyamide. The stable chemical structure of the regulated powder allows it to be recovered and reused multiple times without significant quality loss. This reduces the amount of virgin powder that needs to be discarded or replaced, improving productivity while maintaining component quality through the regulated polyamide's inherent stability.
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 solution enables the reuse of recycling powder with minimal virgin powder, reducing waste and maintaining mechanical properties, ensuring consistent quality and recyclability of components.
Implementation Method 1
In this process, polymer powders in a chamber are selectively, briefly irradiated with a laser beam, resulting in melting of the particles of powder on which the laser beam falls
Implementation Method 2
melting of the particles of powder on which the laser beam falls. The molten particles fuse and solidify again after cooling
Implementation Method 3
The molten particles fuse and solidify again after cooling to give a solid mass
Implementation Method 4
The molten particles fuse and solidify again after cooling to give a solid mass
Implementation Method 5
the powder bed surrounding the melted regions provides sufficient support
Data Source
AI summary
A powder which is capable of being used in a layer-by-layer process in which regions of the respective pulverulent layer are selectively melted and, after cooling, are fixed, contains a mixture of diacid-regulated polyamide and diamine-regulated polyamide and/or diacid-regulated copolyamide and diamine-regulated copolyamide.