Spinning Head Distribution Chamber Tapering for Filament Uniformity

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Solution Overview

Problem

In spinning heads for producing filaments, the mechanical properties of filaments extruded from holes farthest from the feed channel are unsatisfactory due to varying residence time and temperature within the distribution chamber, leading to inferior properties compared to those closer to the feed channel.

Innovation Solution

A spinning head design with a distribution chamber where the distance between the upper and lower surfaces is reduced moving away from the feed channel, either continuously or discontinuously, to minimize residence time and achieve uniform temperature and viscosity across all extrusion holes, resulting in a gradually decreasing volume and reduced residence time for material farthest from the feed channel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the distribution chamber has a constant height (rectangular section), then the structure is simple and easy to manufacture, but the residence time of material varies significantly between holes fed by different distribution channels, leading to non-uniform temperature and viscosity

Engineering Contradiction:

Improvestructural simplicityVSAvoiduniformity of filament properties

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The distribution chamber transitions from a uniform rectangular section to a variable section where the height is reduced progressively in the downstream direction. This creates local variations in chamber volume along the material flow path, specifically reducing the residence time for material traveling to distant extrusion holes while maintaining adequate volume for holes closer to the feed channel.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The geometric parameter of the distribution chamber (height) is changed along the flow direction to control material residence time. By progressively reducing the height from upstream to downstream, the chamber volume available for material residence is reduced for distant holes, thereby equalizing residence times and resulting temperatures across all extrusion holes.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the distribution chamber volume is reduced for distant holes, then the residence time and temperature variability are reduced, but the chamber geometry becomes more complex

Engineering Contradiction:

Improveuniformity of extrusion temperatureVSAvoiddistribution chamber geometry

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The distribution chamber employs a curved, gradually tapering geometry rather than sharp angular transitions. The height reduction is implemented through smooth contours that progressively decrease from upstream to downstream, avoiding abrupt changes while achieving the desired volume reduction for distant holes.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

Instead of modifying the chamber in a single dimension uniformly, the design varies the height dimension specifically in the downstream direction while maintaining other dimensions. This creates an asymmetric geometry that targets the residence time issue for distant holes without unnecessarily complicating the overall structure.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 design ensures more uniform filament properties by reducing the residence time and temperature variability, achieving homogeneous extrusion temperatures across all holes, with a difference of less than 20 minutes in residence time and 10°C in temperature variability.

Implementation Method 1

The path, and therefore the residence time, of the molten material inside the distribution chamber is significantly longer at the holes fed by the distribution channel 3′′, that is to say the holes farthest away from the feed channel 5

Methodology Applied

Scientific EffectResidence time effect:

Implementation Method 2

The Applicant found that this difference in properties is affected by the different residence time of the material inside the distribution chamber, depending on the extrusion hole from which the material is extruded, so that the temperature (and therefore the fluidity/viscosity) of the material can vary significantly between holes of different series

Methodology Applied

Scientific EffectTemperature uniformity through residence time control:

Implementation Method 3

the temperature (and therefore the fluidity/viscosity) of the material can vary significantly between holes of different series

Methodology Applied

Scientific EffectViscosity uniformity through residence time control:

Data Source

PatentUS20250003114A1Spinning head and relative apparatus for the production of filaments

Publication Date: 2025.01.02 FARE

AI summary

A spinning head comprises a feed channel for feeding material to be extruded, a distribution chamber, and an extrusion surface having a plurality of extrusion holes, wherein the distribution chamber comprises a lower surface and an upper surface opposite said lower surface, wherein the distance between the upper surface and the lower surface of the distribution chamber is reduced. The distance reduction may be a substantially continuous reduction or a discontinuous reduction in which, in the upper surface, a plurality of first portions substantially parallel to the lower surface alternate with a plurality of second portions inclined with respect to the lower surface.