Graphene-Coated Polymer Powder for Conductive, Flowable Composites
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Solution Overview
Problem
Existing polymer powders lack sufficient electrical conductivity, leading to issues such as static charge buildup, reduced flowability, and brittle composites when high concentrations of conductive fillers are used, limiting their applications in manufacturing techniques like additive manufacturing and molding.
Innovation Solution
A composite powder material comprising particulate polymers coated with graphene at concentrations of 0.03-1.5% by weight, enhancing electrical conductivity and mechanical strength while maintaining processability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high concentrations of conductive fillers (metal, carbon black) are added to polymer powder to improve electrical conductivity, then electrical conductivity is improved, but the composite becomes brittle and difficult to process
Solution Approach 1:
The patent applies local quality by coating only the surface of polymer particles with graphene rather than mixing graphene uniformly throughout the bulk material. This surface coating approach provides sufficient electrical conductivity at the particle level while maintaining the bulk polymer's mechanical properties and processability.
Solution Approach 2:
The patent creates a composite structure where graphene-coated polymer particles form a conductive network when packed together. The graphene layers on particle surfaces create conductive pathways through contact between particles, achieving bulk conductivity without compromising the polymer matrix integrity.
2Reliability
If high concentrations of conductive fillers are added to improve electrical conductivity, then electrical conductivity is improved, but flowability decreases due to static charge buildup and dusting
Solution Approach 1:
By applying graphene coating only to the particle surface rather than bulk mixing, the patent reduces overall filler content while achieving conductivity. This lower filler concentration minimizes static charge accumulation and maintains better powder flow characteristics.
Solution Approach 2:
The patent changes the concentration parameter of conductive filler from high bulk loading (typically 20-40 wt%) to low surface coating (0.1-5 wt% graphene), fundamentally altering the system's electrical and rheological properties to achieve both conductivity and flowability.
3Reliability
If carbon-based fillers are added at high inclusion levels to improve electrical conductivity, then electrical conductivity is improved, but processability is limited and embrittlement occurs
Solution Approach 1:
The surface coating methodology concentrates graphene at particle interfaces where it is needed for conductivity, while leaving the bulk polymer matrix unchanged and easily processable. This localized approach eliminates the embrittlement and processing difficulties associated with high bulk filler loading.
Solution Approach 2:
The patent creates a hierarchical composite structure with graphene-coated particles forming a conductive network in the bulk polymer. This structure achieves conductivity through particle-particle contact rather than requiring high filler content, maintaining excellent processability.
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 coated polymer powders exhibit improved electrical conductivity, reduced static charge, and enhanced mechanical properties, enabling effective use in manufacturing techniques like SLS printing, rotational molding, and injection molding.
Implementation Method 1
the polymer-graphene composite material can exhibit electrical conductivity
Implementation Method 2
due to the low conductivity of the powder static charges can build up on the powder surface while handling the powder
Data Source
AI summary
The present disclosure relates to conducting polymer powder. In particular, it relates to composite powder material including particulate polymer and graphene, wherein the particulate polymer is coated with graphene, and wherein the graphene concentration is 0.03-1.5% in weight per weight of the particulate polymer. The polymer is selected from the group consisting of polyamide, thermoplastic fluoropolymer, polyethylene, and polyurethane. The polyamide is selected from the group consisting of PA6, PA11, PA12, PA66.