PTFE Extrusion Device with Expansion Chamber for Fiber Orientation

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Solution Overview

Problem

Existing extruders for PTFE materials lack the ability to precisely control the orientation of fibers and adjust the number of diagonal fibers in the final product, resulting in unsatisfactory fiber orientation and excessive gap sizes, which affects the mechanical properties and insulating efficiency of the produced strips or sheets.

Innovation Solution

A device with a detachable design featuring a first expansion chamber with upstream and downstream restriction sections, allowing for the insertion of interchangeable calibrating elements to adjust the passage size, thereby controlling the number of diagonal fibers and optimizing fiber orientation, leading to a thicker, more flexible, and insulating product.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional extruder with a fixed restriction section is used, then the extrusion process is simple, but the fiber orientation cannot be precisely controlled and the number of diagonal fibers cannot be adjusted

Engineering Contradiction:
Improvefiber orientation precisionVSAvoidextruder structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The extruder is divided into multiple independent sections: a first restriction section, a first expansion chamber, a second restriction section, and a second expansion section. This segmentation allows each section to independently control fiber orientation at different stages, achieving precise fiber orientation control while maintaining a manageable overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The extruder incorporates adjustable components including interchangeable calibrating elements with different geometries that can be inserted into the first expansion chamber, and variable opening angles of the second expansion section. These dynamic adjustments enable precise control over diagonal fiber numbers and overall fiber orientation without requiring complete device redesign.

Inventive Principle:
Principle #15Dynamics

2Strength

If the restriction section is made smaller to increase fiber intersection, then the mechanical strength improves, but the gap size becomes too small affecting waterproof functionality

Engineering Contradiction:
Improvemechanical strengthVSAvoidgap size for waterproofing
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The restriction function is split into two separate restriction sections positioned at different locations in the extrusion path. The first restriction section (with calibrating element) controls fiber intersection and diagonal fiber formation in the expansion chamber, while the second restriction section controls the final extrusion geometry. This segmentation allows independent optimization of fiber intersection density and gap size for waterproofing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first expansion chamber acts as an intermediary zone between the two restriction sections. It provides a controlled expansion environment where fibers can be oriented and intersected under the influence of the first restriction section, then gradually transition to the final configuration controlled by the second restriction section. This intermediary expansion chamber enables gradual fiber reorganization without creating excessive gaps.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If the number of diagonal fibers is increased to improve mechanical properties, then the fabric strength increases, but the production flexibility decreases

Engineering Contradiction:
Improvefabric strengthVSAvoidproduction flexibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The extruder employs interchangeable calibrating elements with different geometries, sizes, and surface characteristics that can be inserted into the first expansion chamber. By changing these calibrating elements, the number of diagonal fibers and their orientation can be dynamically adjusted to match different product requirements, maintaining production flexibility while achieving high fabric strength when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The extruder design integrates multiple functions into a single device: it can produce products with varying diagonal fiber numbers, control fiber orientation angles, adjust gap sizes, and maintain different extrusion rates. The interchangeable calibrating elements and adjustable expansion sections enable one device to serve multiple product specifications, enhancing versatility without sacrificing mechanical strength capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 device achieves a high number of intersecting fibers with precise orientation, enhancing the mechanical and insulating qualities of the PTFE strips or sheets, while allowing for flexibility in producing products with varying numbers of diagonal fibers based on specific requirements.

Implementation Method 1

PTFE is an acronym to indicate a known material, that is polytetrafluoroethylene. It is a tetrafluoroethylene polymer which belongs to the olefin group... Such a PTFE can be in the form of paste. In that case, it is malleable according to the present invention, as it has the tendency to distorts in fibers or filamented form.

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

the realization method of the aforementioned sheets or strips of PTFE foresees the extrusion of spheres by means of a suitably shaped extruder

Methodology Applied
Scientific EffectExtrusion: Extrusion

Implementation Method 3

Said extrusion paths forming, in exiting from said first expansion chamber (8), a second expansion section (10)... Such a passage, during the extrusion, determines a flow pace of pasty material such that a part of fibers is arranged in diagonal way with respect to the first part with different angles.

Methodology Applied
Scientific EffectViscoelastic flow: Viscoelasticity

Data Source

PatentEP3210749B1Device and method for extruding a strip or sheet of PTFE material
Publication Date: 2018.12.12 FLON PROJECT SRL
  • EP3210749B1 patent drawingFigure 1
  • EP3210749B1 patent drawingFigure 2
  • EP3210749B1 patent drawingFigure 3

AI summary

The present invention refers to a device (1) for the production of a tape (110) or a sheet (110) of PTFE material and comprising: - An extrusion path (6, 8, 10, 11) of the material; - An opening (6) through which to feed the material in the extrusion path; - An output section (11) through which the extruded material exits from the device (1); According to the invention, said extrusion path (6, 8, 10, 11) forms at least a first expansion chamber (8) whose input and output in/from said expansion chamber (8) are in the form of a restriction section (7, 9).