Straight Axis Nozzle Hopper Alignment for Rigid Filament 3D Printing

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Solution Overview

Problem

Existing FFF machines are limited by the flexibility of build materials, which restricts the choice of materials and results in three-dimensional objects with poor mechanical properties compared to injection molding.

Innovation Solution

The nozzle opening and hopper opening are aligned on a straight axis, allowing build materials with higher viscosity and non-flexible materials to be used, with reduced residence time in a flowable state, enabling the use of materials like glass fiber-filled thermoplastics and thermally conductive fillers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If flexible build material is used to allow winding around a bobbin and easy transport, then ease of operation and material transport are improved, but the choice of materials is limited and mechanical properties deteriorate

Engineering Contradiction:
Improvematerial transportVSAvoidchoice of materials
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The build material is segmented into discrete elements ( pellets, flakes, or short fibers) rather than requiring continuous flexible filament. These segmented materials are fed individually through the hopper opening into the heating zone, eliminating the need for flexibility while enabling diverse material selection including rigid and thermally conductive materials.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A hopper opening aligned with the nozzle opening on a straight axis serves as an intermediary structure that receives segmented build material and directs it into the heating zone. This intermediary allows rigid materials to be transported and processed without requiring flexibility, while maintaining efficient material flow to the nozzle.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If build material residence time in flowable state is reduced, then material viscosity and mechanical properties are improved, but processing efficiency may worsen

Engineering Contradiction:
Improvemechanical propertiesVSAvoidprocessing efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The hopper opening is positioned to deliver build material directly into the heating zone where it is rapidly heated to flowable state and immediately directed to the nozzle. This preliminary positioning and rapid processing minimize residence time in the flowable state, preventing excessive heating that would degrade mechanical properties while maintaining processing efficiency through continuous material flow.

Inventive Principle:
Principle #10Preliminary action

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 enhances the mechanical performance of three-dimensional objects by allowing the use of rigid and thermally conductive materials, improving Young's modulus and maintaining filler orientation, resulting in objects with improved mechanical properties.

Implementation Method 1

a heating element connected to the movable nozzle... heating the build material to a flowable state

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

Upon leaving the movable nozzle, the build material cools in the surrounding air and transitions back to the non-flowable state

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3268211B1Apparatuses and methods for forming three-dimensional objects
Publication Date: 2023.08.09 STRATASYS INC
  • EP3268211B1 patent drawingFigure 1
  • EP3268211B1 patent drawingFigure 2
  • EP3268211B1 patent drawingFigure 3

AI summary

Apparatus and methods for producing three-dimensional objects are disclosed. The apparatus for solid freeform fabrication comprises a movable nozzle (1) comprising a nozzle opening (2), a heating element (3) connected to the movable nozzle, a driver (4) connected to the movable nozzle, a platform (5) for receiving a build material (8) from the movable nozzle, and a hopper (6) for providing the build material to the driver, the hopper comprising a hopper opening (7), wherein the nozzle opening and the hopper opening are capable of simultaneous alignment on a straight axis such that the build material, when present, is capable of traveling along the straight axis at least from the hopper opening until the build material attains a flowable state.