3D Printing Nozzle for Cement Wall Density Gradient Control

Solution Overview

Problem

Existing methods for creating cementitious walls with carbon dioxide fail to optimize the density gradient, leading to issues such as poor bonding, delamination, and suboptimal carbon dioxide distribution, resulting in uneven density layers and potential structural weaknesses.

Innovation Solution

A 3D printing system with a mixing nozzle assembly that controls the density gradient by combining cementitious material with pressurized gaseous bubbles, specifically carbon dioxide, using vanes to create a uniform density transition from high to low density across the wall, ensuring balanced carbon dioxide distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If uniform cellular foam slurry is poured into wall system molds, then the wall structure is simple to manufacture, but distinct layers of differing densities are created leading to poor bonding and delamination

Engineering Contradiction:

Improveease of manufactureVSAvoidbonding quality

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by creating different density regions within the same wall structure. The mixing nozzle assembly produces a continuous density gradient where the center portion has lower density (higher foam content) and the edge portions have higher density (lower foam content). This allows each region to be optimized for its specific function while maintaining overall structural integrity and bonding quality.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by controlling the density gradient through the mixing nozzle assembly. By adjusting the flow rates of cementitious material and gaseous bubbles, and controlling the mixing dynamics in the mixing chamber, the system creates a continuous transition in density from the center to the edges of the deposited material layer.

Inventive Principle:

Principle #35Parameter changes

2Strength

If carbon dioxide is exposed to the interior of the foamed structure, then carbonation and compression strength are improved, but excess carbon dioxide blocks off from reaching inner structure due to mineralization expansion

Engineering Contradiction:

Improvecompression strengthVSAvoidcarbon dioxide distribution

Core Design Contradiction:

StrengthVSQuantity of substance

Solution Approach 1:

The patent applies local quality by creating different density regions within the same wall structure. The mixing nozzle assembly produces a continuous density gradient where the center portion has lower density (higher foam content) and the edge portions have higher density (lower foam content). This allows each region to be optimized for its specific function while maintaining overall structural integrity and bonding quality.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by controlling the density gradient through the mixing nozzle assembly. By adjusting the flow rates of cementitious material and gaseous bubbles, and controlling the mixing dynamics in the mixing chamber, the system creates a continuous transition in density from the center to the edges of the deposited material layer.

Inventive Principle:

Principle #35Parameter changes

3Temperature

If foam concrete is used for thermal insulation, then insulative properties are improved, but distinct layers with different densities create delamination

Engineering Contradiction:

Improvethermal insulationVSAvoidlayer stability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent applies local quality by creating different density regions within the same wall structure. The mixing nozzle assembly produces a continuous density gradient where the center portion has lower density (higher foam content) and the edge portions have higher density (lower foam content). This allows each region to be optimized for its specific function while maintaining overall structural integrity and bonding quality.

Inventive Principle:

Principle #3Local quality

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

Achieves improved bonding, reduces delamination, and optimizes density gradients for enhanced structural integrity and carbon dioxide sequestration without adverse effects on the wall's surface.

Implementation Method 1

using vanes to create fluid eddies and control the distribution of carbon dioxide

Methodology Applied

Scientific EffectFluid eddies: Turbulence

Implementation Method 2

combining it with a pressurized gaseous bubble mix, using vanes to create fluid eddies

Methodology Applied

Scientific EffectGas expansion: Pressure Gradient

Implementation Method 3

the carbon dioxide captured in the foam increases the carbonation process of concrete, particularly on the interior of the foamed structure. In concrete or cementitious structures, carbonation increases the formation of calcium carbonate, a crystalline structure that improves the compression strength of the overall material

Methodology Applied

Scientific EffectCarbonation: Absorption (physical)

Data Source

PatentUS12611818B2Mechanism to control the density gradient in three-dimensionally printed material

Publication Date: 2026.04.28 ARC VENTURES LLC

AI summary

Systems, methods and devices to create a wall system having a cross sectional density gradient obtained by structural 3D printing are disclosed. A mechanism is described that accepts a cementitious material and combines it with a gaseous bubble mixture and then partially mixes the various materials in such a controlled manner as to create a density gradient. The gaseous mixture may be primarily composed of carbon dioxide.