Rotating-Core Extrusion Die with Fixed Male Divergent Support

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Solution Overview

Problem

Existing rotating core extrusion dies for materials rich in protein and water face mechanical constraints, such as deformation and lack of coaxiality, due to substantial hydrostatic thrust forces applied to the rotating core, which complicates the fibration process and affects the quality of the extruded product.

Innovation Solution

A rotating core extrusion die design featuring a fixed male divergent secured to the casing, which channels the material flow and supports the rotating core, allowing hydrostatic thrust forces to be localized and absorbed by the casing, maintaining coaxiality and reducing mechanical stress on the supporting structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a rotating core extrusion die is used for materials rich in protein and water, then fibration efficiency is improved, but mechanical constraints such as deformation and loss of coaxiality occur due to substantial hydrostatic thrust forces

Engineering Contradiction:
Improvefibration efficiencyVSAvoidcoaxiality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

A stationary cone-shaped divergent is introduced as an intermediary component between the material flow and the rotating core. This divergent absorbs the hydrostatic thrust forces from the material, preventing them from being transmitted to the rotating core. The divergent acts as a mechanical mediator that protects the rotating core from excessive axial loads while maintaining the fibration function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The die is segmented into distinct functional zones: a stationary divergent section that handles axial force absorption, and a rotating core section that provides fibration. This segmentation allows each component to be optimized for its specific function without compromising the other, enabling the rotating core to focus on fibration while the divergent handles mechanical loading.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the rotating core is directly supported by the supporting structure, then structural simplicity is maintained, but deformation occurs under substantial hydrostatic thrust forces

Engineering Contradiction:
Improvesupport structure simplicityVSAvoidresistance to deformation
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The stationary divergent serves as a mediator between the material flow and the supporting structure. It absorbs and distributes the hydrostatic thrust forces to the supporting structure in a controlled manner, preventing concentrated loads that would cause deformation of the rotating core or supporting structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the die is designed with a fixed male divergent secured to the casing, then coaxiality is maintained and mechanical stress is reduced, but device complexity increases

Engineering Contradiction:
ImprovecoaxialityVSAvoiddie structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The male divergent is merged with the die casing through fixed securing, creating an integrated stationary component. This combination ensures coaxiality between the divergent and casing while simplifying the overall structure by eliminating separate adjustable components. The integrated design reduces mechanical stress paths while maintaining precision.

Inventive Principle:
Principle #5Merging (Combining)

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

The die provides improved practicality and efficiency by maintaining coaxiality and controlling fibration conditions, reducing mechanical stress, and enabling easy mobility of the supporting structure, thus enhancing the quality and consistency of the extruded food product.

Implementation Method 1

a passage is delimited, by which the central inlet of the casing and the upstream end of the channel are connected and which is shaped so that the material pushed through the die progresses in the passage, from the central inlet of the casing towards the upstream end of the channel, forming a flow of material which diverges from the axis towards the downstream

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

The fibration rate of the material is adjustable in particular by adjusting the speed with which the rotating core is driven

Methodology Applied
Scientific EffectShear stress: Shear Stress

Implementation Method 3

this material undergoes both an essentially mechanical transformation, by pressurization and shearing by the screws

Methodology Applied
Scientific EffectPressurization: Pressurisation

Implementation Method 4

an essentially thermal transformation, by regulating the temperature along the extruder barrel

Methodology Applied
Scientific EffectThermal transformation: Heating

Implementation Method 5

The material in contact with the cooled wall of the channel tends to adhere to this wall, which allows the laminar flow of material in the channel to be sheared

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 6

a die is provided for controlled cooling of the material passing through it, by causing this material to flow in a channel which has both a long length, typically several meters, and a rectangular section, a temperature profile being applied along this channel so as to decrease the temperature of the material progressively between the inlet and the outlet of the channel

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP4623707A1Die for extruding a protein-rich and water-rich material, and system for continuously preparing an extruded food product, comprising such a die
Publication Date: 2025.10.01 CLEXTRAL SA
  • EP4623707A1 patent drawingFigure 1
  • EP4623707A1 patent drawingFigure 2
  • EP4623707A1 patent drawingFigure 3

AI summary

This die (200) comprises a tubular casing (210), centered on an axis (XX), and a coaxial core (220), rotatably mounted around the axis. An upstream portion (220.1) of the core extends into the casing so that a material flow channel (230) is delimited between them, with an annular cross-section and centered on the axis. A downstream portion (220.2) of the core extends outside the casing and is coupled to a rotational drive motor (250). A male divergent part (260) is fixedly secured to the casing and received coaxially in the casing so that a passage (270) is delimited between them, connecting a central inlet (211) of the casing and an upstream end (230A) of the channel. The passage is shaped so that the material progresses therein, forming a flow (6) which diverges from the axis downstream and is distributed around the axis. The male divergent is axially abutted to the upstream part of the core, supporting it and guiding it in rotation.