Filament Buffer for Additive Manufacturing

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Solution Overview

Problem

Current machines for manufacturing additive printed parts face challenges in minimizing the force required to pull polymer filament into the print head, which can be substantial due to the size of the filament coil and resistance, potentially leading to operational disruptions or filament slippage.

Innovation Solution

The introduction of a filament buffer system with a buffer volume that allows the filament to deflect two-dimensionally between side walls, creating slack and reducing the force needed to pull the filament into the print head, while using feed motors within the buffer to manage filament deflection and resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the filament coil is made large to support sufficient filament length, then the filament supply capacity is improved, but the force required to pull the filament increases excessively

Engineering Contradiction:
Improvefilament supply capacityVSAvoidforce required to pull filament
Core Design Contradiction:
Quantity of substanceVSForce

Solution Approach 1:

A filament buffer is introduced as an intermediary component between the filament cartridge and the print head. The buffer contains a buffer volume that allows the filament to deflect and creates slack, thereby reducing the force transmission from the print head to the large filament coil while maintaining sufficient filament supply capacity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If the print head is made small to improve machine compactness, then the machine size is reduced, but the ability to handle high pulling force is compromised

Engineering Contradiction:
Improveprint head sizeVSAvoidpulling force handling capability
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The filament buffer acts as a force-isolating intermediary that allows the print head to remain small while protecting it from experiencing the full pulling force. The buffer volume absorbs mechanical stress and allows filament deflection, enabling compact print head design without compromising force handling capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the filament is pulled directly from the cartridge to the print head without buffer, then the system complexity is reduced, but operational reliability decreases due to filament slippage and disruptions

Engineering Contradiction:
Improvesystem complexityVSAvoidoperational reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The filament buffer provides beforehand cushioning by creating slack and allowing deflection before the filament reaches the print head. This cushioning effect prevents filament slippage and operational disruptions by absorbing mechanical stress and maintaining consistent tension, thereby improving reliability without significantly increasing system complexity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP3908448B1Filament buffer
Publication Date: 2024.05.01 ESSENTIUM INC
  • EP3908448B1 patent drawingFigure 1
  • EP3908448B1 patent drawingFigure 2
  • EP3908448B1 patent drawingFigure 3~4

AI summary

A machine for manufacturing additive printed parts includes a first filament cartridge adapted to support a length of filament of a material from which the additive printed parts will be manufactured, a print head moveably supported within the machine, and a first filament buffer positioned between the first filament cartridge and the print head and including a first buffer volume. The filament supported within the first filament cartridge extends from the first filament cartridge, through the first filament buffer, and to the print head and is allowed to deflect within the first buffer volume.