Knitted Prosthesis Welding for Repeatable Strength and Porosity

Solution Overview

Problem

Textile implants used in surgical operations often lack repeatability in mechanical properties, particularly breaking strength, and require longer production times and higher costs due to traditional stitching methods, which also compromise porosity and flexibility.

Innovation Solution

A prosthesis comprising two pieces of knitted fabric welded together using ultrasonic welding, with welds aligned along the yarn directions to ensure even material distribution and control, maintaining porosity and flexibility, and employing a sonotrode with elongate reliefs for efficient welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional stitching methods are used to assemble knitted fabric pieces, then the mechanical strength and reliability can be maintained, but the production time increases and production costs increase

Engineering Contradiction:

Improvemechanical strength repeatabilityVSAvoidproduction time

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the mechanical stitching process with ultrasonic welding, which uses high-frequency mechanical vibrations to fuse the knitted fabric pieces directly. This substitution eliminates the need for needles and threads, significantly reducing production time while maintaining consistent mechanical properties through automated welding parameters.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the joining method from mechanical stitching to ultrasonic welding by altering the physical parameters of the joining process. Ultrasonic welding uses controlled vibration frequency, amplitude, and pressure parameters to create strong, repeatable welds that match or exceed the mechanical strength of stitched joints, while dramatically reducing production time.

Inventive Principle:

Principle #35Parameter changes

2Strength

If traditional stitching methods are used to assemble knitted fabric pieces, then the mechanical strength can be maintained, but the production costs increase

Engineering Contradiction:

Improvebreaking strengthVSAvoidproduction cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical stitching process with ultrasonic welding, which uses high-frequency mechanical vibrations to fuse the knitted fabric pieces directly. This substitution eliminates the need for needles and threads, significantly reducing production time while maintaining consistent mechanical properties through automated welding parameters.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the joining method from mechanical stitching to ultrasonic welding by altering the physical parameters of the joining process. Ultrasonic welding uses controlled vibration frequency, amplitude, and pressure parameters to create strong, repeatable welds that match or exceed the mechanical strength of stitched joints, while dramatically reducing production time.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If pieces of knitted fabric are assembled by stitching, then the mechanical properties can be defined, but the porosity and flexibility are compromised

Engineering Contradiction:

Improvemechanical properties definitionVSAvoidporosity and flexibility

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent replaces the mechanical stitching process with ultrasonic welding, which uses high-frequency mechanical vibrations to fuse the knitted fabric pieces directly. This substitution eliminates the need for needles and threads, significantly reducing production time while maintaining consistent mechanical properties through automated welding parameters.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the joining method from mechanical stitching to ultrasonic welding by altering the physical parameters of the joining process. Ultrasonic welding uses controlled vibration frequency, amplitude, and pressure parameters to create strong, repeatable welds that match or exceed the mechanical strength of stitched joints, while dramatically reducing production time.

Inventive Principle:

Principle #35Parameter changes

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 method achieves consistent breaking strength and reduced production time and costs while maintaining porosity and flexibility, enhancing the adaptability and biocompatibility of textile implants.

Implementation Method 1

employs a sonotrode to perform ultrasonic welding

Methodology Applied

Scientific EffectUltrasonic welding: Ultrasonic Vibration

Data Source

PatentUS8968419B2Prosthesis comprising knitted material layers and method of manufacturing by ultrasonic welding

Publication Date: 2015.03.03 SOFRADIM PRODUCTION SAS

AI summary

The present invention relates to a prosthesis comprising at least two pieces of knitted fabric and to the method of manufacturing it using a sonotrode to perform ultrasonic welding. The prosthesis comprises at least one first piece of knitted fabric and at least one second piece of knitted fabric, which are welded together by means of a plurality of welds situated in a joining region in which at least a portion of the said first and second pieces of knitted fabric are superposed, the said first and second pieces of knitted fabric each comprising a group of yarns extending respectively in first and second directions A and B, characterized in that the said directions A and B are substantially aligned with one another in the said joining region, and each said weld in the joining region is of elongate shape with its longitudinal axis being aligned with the said directions A and B.