Variable Discharge Print Head for FDM 3D Printing
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Solution Overview
Problem
In additive manufacturing processes like FDM, halting and resuming filament extrusion for repositioning the printing head leads to material leakage and pressure increases, causing inefficiencies and quality issues due to prolonged residence time of molten material in the melting zone, which affects the processing and mechanical properties of thermoplastic polymers.
Innovation Solution
A printing head with a second outlet for pressure release and a control system that adjusts discharge rates to minimize material residence time and maintain consistent pressure, allowing for precise control during repositioning and continuous material flow without interruptions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If filament extrusion is halted during repositioning, then material leakage is prevented, but internal pressure increases causing excessive material issuance upon resumption
Solution Approach 1:
The outlet is divided into two separate outlets: a first outlet for discharging molten construction material and a second outlet for discharging unmolten construction material. This segmentation allows independent control of each outlet's discharge rate, enabling the system to prevent material leakage during repositioning while managing internal pressure through the second outlet without causing excessive material issuance from the first outlet upon resumption.
2Stress or pressure
If filament extrusion is continued during repositioning, then internal pressure is maintained, but material leakage occurs between printing head positions
Solution Approach 1:
The outlet is divided into two separate outlets: a first outlet for discharging molten construction material and a second outlet for discharging unmolten construction material. This segmentation allows the system to maintain internal pressure through continuous extrusion while directing material flow through the second outlet to prevent leakage during repositioning, and to control material issuance from the first outlet upon resumption.
3Stress or pressure
If molten material residence time is prolonged, then pressure stability is maintained, but processing properties and mechanical properties of polymer are impaired
Solution Approach 1:
The system dynamically adjusts the discharge rates of the first and second outlets based on operational requirements. During repositioning, the second outlet discharges unmolten material to maintain pressure stability. During printing, the first outlet discharges molten material at controlled rates. This dynamic control minimizes molten material residence time while maintaining pressure stability, thereby preserving polymer processing properties and 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
This solution reduces material leakage during repositioning, maintains consistent pressure, and minimizes the residence time of molten material, enhancing the precision and quality of 3D printing by ensuring controlled processing times for thermoplastic polymers.
Implementation Method 1
at least one heating element arranged downstream of the inlet and at least intermittently fluidically connected to the inlet for heating the construction material to a temperature above the melting temperature of the construction material
Implementation Method 2
The filamentous construction material is typically conveyed into the melting region of the printing head by roller propulsion or the like
Data Source
AI summary
The invention relates to a print head (100) for an additive fused deposition modelling method having a thermoplastic construction material, comprising:—at least one inlet (10) for receiving a construction material (11) into the print head;—at least one melt region, for melting the construction material (11), which is arranged downstream of the inlet (10) and is fluidically connected, at least temporarily, to the inlet (10); and—at least one first outlet (30) that is fluidically connected, at least temporarily, to the melt region (20), for discharging melted construction material (12) out of the melt region (29) at a first discharge rate; wherein—the print head (100) also comprises at least one second outlet (40) that is fluidically connected, at least temporarily, to the melt region (20) for discharging melted or non-melted construction material (11, 12) out of the melt region (20) at a second discharge rate; and—the first discharge rate can be influenced by a first discharge rate influencing device (50) for the melted construction material (12).