Cement Extrusion Control With Sensor-Guided Additive Dosing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing systems for extruding cementitious materials in additive manufacturing lack precise control over the properties of the printing composition, leading to inefficiencies and suboptimal quality of the printed material.

Innovation Solution

A system and method that incorporates temperature and pressure sensors in a closed loop with a control unit to adjust the amount of additives in the cementitious material, using a mixing chamber and extruder with a motor-driven mixer, ensuring homogenous mixing and controlled extrusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If temperature and pressure sensors are integrated with a control unit to adjust additive amounts in real-time, then the manufacturing precision and quality of the printed material are improved, but the device complexity increases due to additional sensors and control systems

Engineering Contradiction:
Improvecontrol over printing composition propertiesVSAvoidcontrol system and sensor integration
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system integrates temperature and pressure sensors that continuously monitor the printing composition properties and feed this data back to a control unit. The control unit automatically adjusts the amount of additives in real-time based on the sensor readings, creating a closed-loop feedback system that maintains precise control over material properties without requiring manual intervention.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention replaces manual or mechanical adjustment methods with automated electronic control. Instead of physically adjusting additive amounts through mechanical means, the system uses electronic sensors and a control unit to automatically regulate the composition, substituting mechanical adjustment with intelligent automated control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If a motor-driven mixer is used to ensure homogenous mixing of cementitious material and additives, then the manufacturing precision is improved, but the device complexity and energy consumption increase

Engineering Contradiction:
Improvehomogeneity of mixingVSAvoidenergy consumption of motor-driven mixer
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The motor-driven mixer is designed with variable speed control that allows the mixing process to be dynamically adjusted. The mixer can operate at different speeds depending on the specific mixing requirements - higher speeds for initial mixing and lower speeds for final homogenization - optimizing energy consumption while maintaining mixing quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mixing process is designed to be continuous rather than intermittent, with the motor-driven mixer operating continuously throughout the material preparation phase. This continuous action ensures uniform mixing without interruption, preventing segregation and ensuring homogenous distribution of additives throughout the cementitious material.

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If the system allows faster setting of the printing composition through controlled additives, then the productivity is improved, but the manufacturing precision may be compromised due to reduced working time

Engineering Contradiction:
Improvesetting speed of printing compositionVSAvoidquality of printed material
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system controls the setting speed by precisely adjusting the amount and type of additives introduced into the cementitious material. By changing the chemical composition parameters - specifically the ratio and quantity of setting accelerators or retarders - the system can optimize both the setting speed and the final material quality, allowing faster setting without compromising structural integrity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The additive distribution is optimized to create local variations in setting characteristics. The motor-driven mixer ensures uniform distribution of additives throughout the material, creating consistent local properties that allow controlled setting throughout the entire printed structure, maintaining quality even with accelerated setting times.

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

Enhances the quality and efficiency of the printing process by allowing faster setting of the printing composition, enabling precise control over the properties for improved adhesion and structural integrity of the printed layers.

Implementation Method 1

a mixing chamber (10) comprising a cementitious material inlet (11) connected to said at least one pump of cementitious material via a cementitious material supply line (32), and an inlet of additive for cementitious material (12) connected to said at least one pump of additive for cementitious material via a supply line of additive for cementitious material (33); said mixing chamber (10) being configured to mix the cementitious material with the additive for cementitious material, thereby forming a printing composition

Methodology Applied
Scientific EffectMixing: Stirring

Implementation Method 2

an extruder (20) for extruding at least one layer of the printing composition through an outlet (21) thereof

Methodology Applied
Scientific EffectExtrusion: Extrusion

Implementation Method 3

The extruder (20) comprises at least one temperature sensor, and in that the mixing chamber (10) comprises at least one pressure sensor at the cementitious material inlet (11), each sensor being operatively connected in closed loop to the control unit

Methodology Applied
Scientific EffectTemperature sensing: Thermocouple

Implementation Method 4

The extruder (20) comprises at least one temperature sensor, and in that the mixing chamber (10) comprises at least one pressure sensor at the cementitious material inlet (11), each sensor being operatively connected in closed loop to the control unit

Methodology Applied
Scientific EffectPressure sensing: Pressure Increase

Implementation Method 5

each sensor being operatively connected in closed loop to the control unit, which is configured to adjust the amount of additive for cementitious material in the printing composition based on the temperature and pressure measured by said sensors

Methodology Applied
Scientific EffectFeedback control: Feedback

Data Source

PatentEP4484102B1System and method for extruding cementitious material and system for additive manufacturing of a cementitious material based structure
Publication Date: 2026.02.25 UNIV POLITECNICA DE CATALUNYA
  • EP4484102B1 patent drawingFigure 1
  • EP4484102B1 patent drawingFigure 2
  • EP4484102B1 patent drawingFigure 3

AI summary

It is disclosed a system for extruding cementitious material comprising: - at least one pump (30, 34) of cementitious material; - at least one pump (31) of additive for cementitious material; - a mixing chamber (10) comprising a cementitious material inlet (11) and an inlet (12) of additive for cementitious material; and being configured to mix the cementitious material with the additive for cementitious material forming a printing composition; - an extruder (20) for extruding at least one layer of the printing composition; - a control unit; wherein the extruder (20) comprises at least one temperature sensor (T1), and the mixing chamber (10) comprises at least one pressure sensor (P1) at the cementitious material inlet (11), each sensor (T1, P1) being operatively connected to the control unit, which is configured to adjust the amount of additive for cementitious material in the printing composition. It is also disclosed a method for extruding cementitious material and a system for additive manufacturing of a cementitious material-based structure.