Air-jet Spinning Nozzle Block Geometry for Fiber Control

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Solution Overview

Problem

Conventional spinning machines face issues with entwined fibers during swirling airflow generation, leading to unnecessary asperities and deteriorated yarn properties, and struggle to maintain stable swirling airflow, resulting in weak yarn strength.

Innovation Solution

The spinning machine design includes a draft device with a front roller pair and a spinning device featuring a nozzle block with a cylindrical space part, a spindle, and air nozzles that satisfy specific geometric relationships to reduce fiber entwining and stabilize the swirling airflow, ensuring a predetermined yarn strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the swirling airflow generation chamber is made narrow to efficiently generate swirling airflow, then energy efficiency is improved, but fiber entwining increases causing yarn quality deterioration

Engineering Contradiction:
Improveenergy efficiency of swirling airflow generationVSAvoidyarn quality
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The swirling airflow generation chamber is divided into multiple sections along the yarn feeding direction, with each section having a different diameter. The upstream section has a smaller diameter for efficient swirling airflow generation, while the downstream section has a larger diameter to prevent fiber entwining. This segmentation allows both energy efficiency and yarn quality to be optimized simultaneously.

Inventive Principle:
Principle #1Segmentation

2Use of energy by stationary object

If the diameter of the space part is reduced to improve swirling airflow efficiency, then energy usage is improved, but fiber length relative to chamber size increases causing more fiber entanglement

Engineering Contradiction:
Improveenergy usage for airflow generationVSAvoidfiber entanglement
Core Design Contradiction:
Use of energy by stationary objectVSObject-affected harmful factors

Solution Approach 1:

The solution transitions from a uniform cross-sectional chamber to a variable cross-sectional chamber where the diameter changes along the longitudinal axis. This dimensional variation allows the chamber to provide both the confined space needed for efficient swirling airflow generation and the additional room needed to accommodate long fibers without entanglement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If air nozzles are positioned to face the reversal chamber directly, then swirling airflow generation is simplified, but jet air stream causes fiber disturbance and entwining

Engineering Contradiction:
Improveswirling airflow generation mechanismVSAvoidfiber arrangement
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The air nozzles are positioned to blow air at a specific location and angle that creates a gentle guiding airflow rather than a direct jet into the reversal chamber. This localized airflow control prevents fiber disturbance and entwining while still achieving the desired swirling motion, maintaining both simplicity and precision.

Inventive Principle:
Principle #3Local quality

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 design effectively reduces fiber entwining, enhances yarn quality by minimizing asperities, and stabilizes the swirling airflow to produce a spun yarn with improved strength and feel.

Implementation Method 1

air is injected from the air nozzle to the tip of the spindle, a swirling airflow is generated in a swirling airflow generation chamber that is a space formed between the nozzle block and the spindle

Methodology Applied
Scientific EffectSwirling airflow: Vortex Ring

Implementation Method 2

Air nozzles formed in the nozzle block and inclining to the downstream side of the yarn feeding direction toward the cylindrical space part

Methodology Applied
Scientific EffectFluid spray: Fluid Spray

Data Source

PatentEP2009150B2Air-jet spinning machine
Publication Date: 2018.01.10 MURATA MASCH LTD
  • EP2009150B2 patent drawingFigure 1
  • EP2009150B2 patent drawingFigure 2
  • EP2009150B2 patent drawingFigure 3

AI summary

The present invention provides a spinning machine which can prevent reversed twine fibers in swirling from entwining each other without setting a diameter of a space part of a nozzle block to be an unnecessarily large size. It is assumed that the diameter of a cylindrical space part 43 is T, an inclination angle of an air nozzle 34 with respect to a plane surface orthogonal to an axis direction of the cylindrical space part 43 is θ, and a length from a nipping point P at which the twine fibers 46 nipped by the front roller pair 22 are released to a center R of the entrance of a yarn passage hole 39 is L. And, when a relation of T≥Lcosθ/π, is assumed, the twine fibers 46 reversed by a swirling airflow almost go around along the periphery wall of the cylindrical space part 43, that is, the inner periphery wall 44 of the nozzle block 33 in being reversed and in a planer view seen from the axis direction of the cylindrical space part 43. Therefore, the twine fibers 46 in swirling can be hardly entwined each other (Fig 2).