3D Printing System Surface Melting Expanded Polymer Strand

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Solution Overview

Problem

Conventional 3D printing methods for foamed products are limited in producing hybrid articles with both foamed and non-foamed sections, lack control over foam structure and density, and result in unstable objects due to non-firm adhesion of polymer strands.

Innovation Solution

A 3D printing system that deposits an expanded polymer strand with a crystalline core and amorphous outer layer, using a printing device with a surface melting section to selectively melt the surface for adhesion and control the foam structure and density by varying the blowing agent concentration and type, allowing for hybrid articles and stable object production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional 3D printing methods are used to produce foamed products, then the production process is simple, but the foam structure and density cannot be controlled

Engineering Contradiction:
Improvefoam structure controlVSAvoidprinting device structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The printing device is divided into distinct functional sections: a feed section for introducing polymer material, a transporting section for moving the material, a surface melting section for selective melting, and a terminal printing head section for deposition. This segmentation allows independent optimization of each section to achieve both foam structure control and manageable device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention controls foam structure and density by varying parameters such as blowing agent concentration, melting temperature, and deposition conditions. By adjusting these parameters in the surface melting section, the patent achieves precise control over the expanded polymer's foam characteristics without requiring complex additional equipment.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If polymer strands are deposited without surface melting, then the production process is faster, but adhesion between strands is poor resulting in unstable objects

Engineering Contradiction:
Improveobject stabilityVSAvoidproduction speed
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

Instead of melting the entire polymer strand, the invention applies partial melting only to the surface layer of the strand. This selective surface melting provides sufficient adhesion for stable object construction while minimizing the energy and time required compared to complete melting, thus maintaining production efficiency.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The surface melting section pre-treats the polymer strand surface before deposition by melting it slightly. This preliminary action creates an adhesive surface that ensures proper bonding between strands upon deposition, guaranteeing object stability without requiring additional post-processing steps.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If uniform foaming is applied throughout the polymer, then the material consistency is high, but hybrid articles with both foamed and non-foamed sections cannot be produced

Engineering Contradiction:
Improvehybrid article productionVSAvoidmaterial consistency
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The invention enables different sections of the polymer material to have different foam characteristics by controlling the blowing agent distribution and melting conditions locally. This allows the production of hybrid articles with both foamed and non-foamed sections, each with appropriate material consistency for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts foaming parameters during the printing process based on the desired article configuration. By varying blowing agent concentration and melting conditions in real-time, the invention can switch between producing uniformly foamed sections and non-foamed sections, enabling hybrid article production while maintaining material consistency within each section.

Inventive Principle:
Principle #15Dynamics

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

Enables the production of flexible, stable three-dimensional objects with controlled foam structure and density, allowing for the creation of hybrid articles and improved adhesion between polymer strands, resulting in more stable foamed products.

Implementation Method 1

the surface melting section comprises a solid-state welding element, a laser beam, a generator of hot gas or liquid and/or a generator of heat by an exothermal reaction

Methodology Applied
Scientific EffectSelective melting: Melting

Implementation Method 2

an expanded polymer strand with a crystalline core and amorphous outer layer

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentUS11958237B23D printing system for preparing a three-dimensional object with a surface melting section
Publication Date: 2024.04.16 SULZER MANAGEMENT AG

AI summary

A three-dimensional (3D) printing system for preparing an object made at least partially of an expanded polymer including: a printing device for transporting and depositing a strand of expanded polymer including a blowing agent onto a surface and a 3D movement device for adjusting the position of the printing device in a predefined matrix allowing deposit of the strand of expanded polymer at a predetermined time and precise position within the matrix, the printing device includes: a feed section, a transporting section, a surface melting section, and a terminal printing head section for depositing the expanded polymer strand onto the surface, and all of sections have the same inner diameter, and the surface melting section including a solid-state welding element, a laser beam, a generator of hot gas or liquid and/or a generator of heat.