Segmented Polymer Filament for 3D Printing Weld Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current three-dimensional printing technologies face challenges in achieving high mechanical and functional properties while maintaining geometric accuracy, as existing thermoplastic filaments either compromise on mechanical stability or geometric precision due to limitations in weldline performance and material blending techniques.
Innovation Solution
The development of preforms or filaments composed of two or more materials with differing flow temperatures arranged in a regular geometric pattern, allowing the lower flow temperature polymer to fill voids and form strong weldlines while the higher flow temperature polymer maintains mechanical stability, enabling the production of parts with improved mechanical and functional properties without compromising geometric accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If FFF is executed at higher temperature, then the thermoplastic has high flow and forms strong thermoplastic welds between print lines and layers, but geometric accuracy deteriorates due to part sag, shrinkage, or warpage
Solution Approach 1:
The filament is segmented into distinct functional regions: a core material providing mechanical stability and a shell material providing flow capability. This segmentation allows each material to perform its specialized function without compromising the other, resolving the contradiction between weld strength and geometric accuracy.
Solution Approach 2:
The invention uses composite filament structure with multiple materials having different thermal and mechanical properties. The core-shell configuration creates a composite material system where the inner core provides dimensional stability while the outer shell enables proper flow and welding, simultaneously achieving both high weld strength and geometric accuracy.
2Manufacturing precision
If FFF is executed at lower temperature, then geometric accuracy is improved, but mechanical stability deteriorates due to insufficient weldline fusing
Solution Approach 1:
The filament structure segments the welding function to the outer shell material while the core material maintains dimensional stability. This allows the process to occur at lower temperatures where the core remains stable but the shell can still achieve proper flow and welding.
Solution Approach 2:
Different regions of the filament have different thermal and mechanical properties tailored to their specific functions. The outer shell has lower melting point and higher flow capability for welding, while the inner core has higher thermal stability for maintaining geometric accuracy, enabling local optimization of 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
This approach allows for the creation of three-dimensional printed parts with enhanced mechanical strength, reduced surface roughness, and maintained geometric accuracy, as well as the ability to produce complex cross-section fibers with tailored properties, such as optical waveguides and microfluidic channels, using a more economical and efficient process.
Implementation Method 1
Thermoplastics exhibit viscoelastic thermal softening, in which elastic stiffness and viscosity reduce gradually as temperature is increased
Implementation Method 2
heating the preform and pulling the preform under tension to draw the preform into a filament
Data Source
AI summary
A thermoplastic filament comprising multiple polymers of differing flow temperatures in a regular geometric arrangement, and a method for producing such a filament, are described. Because of the difference in flow temperatures, there exists a temperature range at which one polymer is mechanically stable while the other is flowable. This property is extremely useful for creating thermoplastic monofilament feedstock for three-dimensionally printed parts, wherein the mechanically stable polymer enables geometric stability while the flowable polymer can fill gaps and provide strong bonding and homogenization between deposited material lines and layers. These multimaterial filaments can be produced via thermal drawing from a thermoplastic preform, which itself can be three-dimensionally printed. Furthermore, the preform can be printed with precisely controlled and complex geometries, enabling the creation of monofilament and fiber with unique decorative or functional properties.