Air Spinning Machine False Twist Pre-Drafting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional spinning processes, such as ring and rotor spinning, have reached productivity limits, and air-jet spinning faces issues with fiber deflection and detachment due to air flow from drafting system output rollers, leading to quality fluctuations and increased hairiness in yarn as spinning speed increases.

Innovation Solution

A false twist element is introduced in the pre-drafting zone to impart alternating twists to the sliver before the main drafting zone, ensuring fiber adhesion and reducing deflection by the air flow, with a four-roller drafting system and a pneumatically actuated nozzle providing precise fiber alignment and compaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the rotational speed of drafting system output rollers is increased to achieve higher spinning speed, then productivity is improved, but air flow deflects and detaches individual fibers from the sliver, deteriorating yarn quality

Engineering Contradiction:
Improvespinning speedVSAvoidyarn quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

A false twist element is introduced in the pre-drafting zone to impart alternating twists to the sliver before it enters the main drafting zone. This preliminary action creates fiber adhesion and reduces deflection by the air flow generated by high-speed rollers, allowing high spinning speeds to be maintained without quality deterioration.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The false twist element applies alternating twists to the sliver in advance, before the main drafting process. This preliminary twisting action prepares the fiber structure to resist air flow effects during high-speed spinning, preventing fiber detachment and maintaining yarn quality at high productivity levels.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If a false twist element is introduced in the pre-drafting zone to reduce fiber deflection, then yarn evenness is improved, but device complexity increases

Engineering Contradiction:
Improveyarn evennessVSAvoiddrafting system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The false twist element is pneumatically actuated, using compressed air to generate the alternating twists. This pneumatic actuation avoids complex mechanical moving parts, reducing device complexity while maintaining the ability to impart false twist effectively for improved yarn evenness.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The mechanical false twist device is replaced with a pneumatic system that uses air jets to impart alternating twists. This substitution eliminates complex mechanical linkages, motors, and control systems while achieving the same functional effect of reducing fiber deflection and improving yarn evenness.

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

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

This solution enhances yarn evenness and reduces hairiness by maintaining fiber adhesion, resulting in a high-quality, air-spun yarn with improved uniformity and reduced fiber loss during the spinning process.

Implementation Method 1

a pneumatically actuated nozzle providing precise fiber alignment and compaction

Methodology Applied
Scientific EffectPneumatic action:

Implementation Method 2

even minor negative influences on the drafting process, such as the air flow caused by the rotational speed of the drafting system output rollers, deflect individual fibers from the sliver

Methodology Applied
Scientific EffectAir flow:

Implementation Method 3

the twist makes the sliver more compact and edge fibers are tied into the middle. This prevents individual fibers from being deflected out of the sliver by the air flow

Methodology Applied
Scientific EffectTwist-induced compaction:

Data Source

PatentEP2740821B1Air spinning machine
Publication Date: 2016.08.31 SAURER GERMANY GMBH & CO KG
  • EP2740821B1 patent drawingFigure 1
  • EP2740821B1 patent drawingFigure 2

AI summary

The air spinning device has a fiber belt (4) which is stretched by a stretching unit (5) and is supplied to an air spinning equipment (6) for generating a yarn twist, where the fiber belt is withdrawn from the air spinning equipment and is wound onto a cross-wound bobbin. A false twisting unit (41) is arranged in a pre-drafting zone of the stretching unit. The false twisting unit is granted with alternating direction of rotation of the fiber belt, before it is moved in the main drafting zone on yarn count and is supplied to the air spinning equipment.