Heterophasic Polypropylene 3D Filament for Warpage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing propylene-based filaments for 3D printing suffer from warpage issues due to material shrinkage, leading to deformation and detachment of printed objects from the build plate.
Innovation Solution
A filament comprising a filled polyolefin composition with a heterophasic polypropylene composition and a filler, such as glass fibers, which improves mechanical properties and reduces warpage by incorporating a propylene homopolymer and ethylene copolymer with specific xylene soluble content and melt flow rates, along with a compatibilizer to enhance compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If propylene based filaments are used for 3D printing, then the filament can be extruded and deposited, but warpage occurs due to material shrinkage causing corners to lift and detach from the build plate
Solution Approach 1:
The patent uses a composite filament structure consisting of a polypropylene base material combined with natural fiber fillers (such as hemp, flax, or jute fibers). This composite approach allows the filament to maintain extrusibility while the natural fibers reinforce the structure and reduce warpage by providing dimensional stability during the printing process. The fibers act as a rigid skeleton that counteracts the shrinkage forces of the polypropylene matrix.
Solution Approach 2:
The patent modifies the material parameters by controlling the fiber content percentage (typically 10-40 wt%), fiber length, and fiber diameter to optimize the balance between extrusibility and warpage resistance. By adjusting these parameters, the filament achieves appropriate melt flow characteristics for extrusion while maintaining sufficient structural integrity to prevent warpage during cooling.
2Ease of operation
If material contracts too much during cooling, then the print bends up from the build plate, but maintaining material properties for extrusion is required
Solution Approach 1:
The natural fiber reinforcement creates a composite material where the fibers provide a rigid framework that resists deformation during cooling. The polypropylene matrix ensures adequate flow and extrusion properties, while the embedded natural fibers act as structural support that prevents the printed object from bending or warping as the material contracts during the phase change from molten to solid state.
Solution Approach 2:
The natural fibers are distributed throughout the polypropylene matrix to provide localized reinforcement at critical stress points. This creates regions of enhanced stiffness and warpage resistance within the material structure, allowing the filament to maintain both extrusion capability and shape stability during the printing process.
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 effectively reduces warpage in 3D printed objects, ensuring better adhesion to the build plate and maintaining object integrity by balancing material shrinkage and expansion.
Implementation Method 1
a heterophasic polypropylene composition comprising: a1) from 30 wt.% to 65 wt.%; of a propylene homopolymer or a propylene/ethylene copolymer having a content of ethylene derived units ranging from 0.1 wt.% to 4.5 wt.%, and having a xylene soluble content measured at 25°C lower than 10 wt.%; a2) from 35 wt.% to 70 wt.% of a propylene ethylene copolymer having a content of ethylene derived units ranging from 35 wt.% to 85 wt.%
Implementation Method 2
an intrinsic viscosity of the fraction soluble in xylene at 25°C ranging from 1.5 to 6.0 dl/g
Implementation Method 3
When plastics are printed, they firstly expand slightly but contract as they cool down. If material contracts too much, this causes the print to bend up from the build plate
Implementation Method 4
A filament for extrusion-based additive manufacturing comprising a filled polyolefin composition having a MFR L (Melt Flow Rate according to ISO 1133, 230°C/2.16 kg load) ranging from 2.0 to 30.0 g/10 min comprising: A) from 60 wt.% to 95 wt.%, preferably from 65 wt.% to 92 wt.%, more preferably from 70 wt.% to 90 wt.%, of a heterophasic polypropylene composition
Data Source
Figure 1
AI summary
A consumable filament and process for using the consumable filament in an extrusion-based additive manufacturing system comprising a heterophasic polypropylene composition having a xylene soluble content ranging from 15 wt% to 50 wt%, a melt flow rate MFR L ranging from 0.5 to 100 g/10 min, an intrinsic viscosity of the fraction soluble in xylene at 25°C ranging from 1.5 to 6.0 dl/g and an ethylene content ranging from 10 wt% to 50 wt%.