Melt Spinning Cooling Air Segmentation for Yarn Stability

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Solution Overview

Problem

The existing methods for manufacturing non-woven fabrics, such as those described in Patent Document 1, suffer from yarn breakage and yarn fluctuation issues due to non-uniform cooling air distribution, which affects the texture and productivity of the fabric.

Innovation Solution

A melt spinning apparatus with a cooling air supply unit divided into two stages in a vertical direction, featuring a gap between the air-permeable partition and the nozzle face, and controlled air velocities and temperatures to minimize turbulence and ensure consistent cooling, along with a honeycomb-shaped air-permeable partition for efficient air regulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a large volume of cooling air is supplied to increase productivity, then the amount of discharged filaments increases, but yarn breakage occurs due to supercooling

Engineering Contradiction:
Improveamount of discharged filamentsVSAvoidyarn breakage
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The cooling air supply is divided into multiple nozzles arranged in the vertical direction, with each nozzle supplying cooling air to a specific region. This segmentation allows different regions to receive appropriately sized cooling air volumes, preventing supercooling while maintaining high overall productivity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different nozzles in the vertical direction supply cooling air with locally optimized volumes and velocities matched to the specific cooling needs of each region. This local quality approach ensures that no region receives excessive cooling air that would cause yarn breakage, while still achieving high overall productivity

Inventive Principle:
Principle #3Local quality

2Temperature

If cooling air velocity is increased to improve cooling efficiency, then filament cooling improves, but yarn breakage occurs due to excessive air force

Engineering Contradiction:
Improvecooling efficiencyVSAvoidyarn breakage
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The cooling air supply is segmented into multiple nozzles, each delivering a distributed, moderate velocity flow rather than a single high-velocity stream. This segmentation reduces the localized air force on filaments while maintaining overall cooling efficiency

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each nozzle is positioned and sized to deliver cooling air with a velocity locally optimized for its specific region, ensuring adequate cooling without excessive air force that would cause yarn breakage

Inventive Principle:
Principle #3Local quality

3Device complexity

If cooling air distribution is non-uniform to simplify the system, then device complexity decreases, but yarn fluctuation occurs due to mass distribution non-uniformity

Engineering Contradiction:
Improvecooling air supply structureVSAvoidmass distribution uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The cooling air supply is segmented into multiple nozzles arranged in the vertical direction, creating a structured yet relatively simple configuration. This segmentation naturally promotes uniform cooling air distribution across different regions, ensuring uniform filament mass distribution and preventing yarn fluctuation while keeping the device structure manageable

Inventive Principle:
Principle #1Segmentation

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 apparatus effectively suppresses yarn breakage and fluctuation, maintaining productivity while ensuring a stable and uniform non-woven fabric texture by optimizing cooling air distribution and temperature control.

Implementation Method 1

cooling air supply unit that supplies cooling air to the cooling unit through an air-permeable partition

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

cooling unit that cools the filaments spun from the spinning nozzles

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3690086B1Melt spinning apparatus and non-woven fabric production method
Publication Date: 2022.05.25 MITSUI CHEMICALS INC
  • EP3690086B1 patent drawingFigure 1
  • EP3690086B1 patent drawingFigure 2
  • EP3690086B1 patent drawingFigure 3

AI summary

A melt spinning apparatus includes a spinning unit including plural spinning nozzles that spin filaments, a cooling unit that cools the filaments spun from the spinning nozzles, and a cooling air supply unit that faces the cooling unit and supplies cooling air to the cooling unit through an air-permeable partition. In the melt spinning apparatus, the cooling air supply unit includes a first cooling air supply unit at a vertically upper side and a second cooling air supply unit at a vertically lower side, divided into two stages in a vertical direction through a partition, there is a gap between an end, facing the air-permeable partition, of the partition and a face of a side, facing the partition, in the air-permeable partition, and the distance (distance A) of the gap is 55 mm or less.