Twisted Liquid-Crystal Polyester Cord Diameter Uniformity

Solution Overview

Problem

Conventional methods for producing twisted cords of liquid-crystal polyester multifilaments result in non-uniform diameters along the longitudinal direction, leading to issues with product shape retention and strength due to uneven stress distribution and low yarn length followability during twisting.

Innovation Solution

A twisted cord of liquid-crystal polyester multifilaments with a coefficient of variation in cord diameters of less than 30% is achieved by using a method that includes twisting multifilaments with a yarn flexibility index of 8.0 or less and bending them in multiple directions during unwinding, ensuring uniformity and improved followability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If liquid-crystal polyester multifilaments are twisted to form a twisted cord, then the cord can be used for various industrial applications, but the cord diameter becomes non-uniform in the longitudinal direction

Engineering Contradiction:

Improveapplication suitabilityVSAvoidcord diameter uniformity

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by bending the multifilament in specific directions before twisting. The multifilament is bent in a first direction, then in a second direction opposite to the first, preparing it in advance to ensure uniform diameter distribution during subsequent twisting operations. This preliminary geometric preparation resolves the contradiction by pre-establishing uniformity before the twisting process begins.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the geometric parameters of the multifilament by controlling the bending directions and angles before twisting. By adjusting these parameters (bending direction, bending angle), the patent achieves uniform cord diameter in the longitudinal direction while maintaining versatility for various industrial applications.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If the multifilament is twisted without prior bending, then the twisting process is simpler, but the yarn length followability decreases and stress distribution becomes uneven

Engineering Contradiction:

Improveprocess simplicityVSAvoidstress distribution uniformity

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent applies preliminary action by bending the multifilament in specific directions before twisting. The multifilament is bent in a first direction, then in a second direction opposite to the first, preparing it in advance to ensure uniform diameter distribution during subsequent twisting operations. This preliminary geometric preparation resolves the contradiction by pre-establishing uniformity before the twisting process begins.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the geometric parameters of the multifilament by controlling the bending directions and angles before twisting. By adjusting these parameters (bending direction, bending angle), the patent achieves uniform cord diameter in the longitudinal direction while maintaining versatility for various industrial applications.

Inventive Principle:

Principle #35Parameter changes

3Shape

If the cord diameter is made uniform through controlled bending, then product shape retention improves, but the processing steps increase

Engineering Contradiction:

Improveproduct shape retentionVSAvoidprocessing steps

Core Design Contradiction:

ShapeVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by bending the multifilament in specific directions before twisting. The multifilament is bent in a first direction, then in a second direction opposite to the first, preparing it in advance to ensure uniform diameter distribution during subsequent twisting operations. This preliminary geometric preparation resolves the contradiction by pre-establishing uniformity before the twisting process begins.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the geometric parameters of the multifilament by controlling the bending directions and angles before twisting. By adjusting these parameters (bending direction, bending angle), the patent achieves uniform cord diameter in the longitudinal direction while maintaining versatility for various industrial applications.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11885047B2Twisted cord of liquid-crystal polyester multifilaments, production method therefor, and product comprising said twisted cord

Publication Date: 2024.01.30 TORAY INDUSTRIES INC

AI summary

The present invention addresses the problem of providing a twisted cord of liquid-crystal polyester multifilaments which gives various high-order processed products capable of retaining desired product shapes and which is suitable for use in general industrial material applications such as high-strength ropes, slings, and nets. The twisted cord of liquid-crystal polyester multifilaments has a coefficient of variation in longitudinal-direction cord diameter, X, of less than 30%.