Interweaving Knot Device Yarn Guide Wrap Angle

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Solution Overview

Problem

Existing devices for producing interlacing knots in multifilament threads generate knots with low stability and large extent, making them unsuitable for further processing, particularly in carpet yarns, where high stability and density are required.

Innovation Solution

The device modifies the arrangement of inlet and outlet yarn guides to increase the contact wrap angle of the thread in the guide groove, ensuring it is greater than the opening angle of the chamber opening on the stator, and optimizes the design to produce short, intense pressure pulses, minimizing air consumption and leakage, while allowing for flexible knot formation and tension adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the nozzle ring has a large number of nozzle bores evenly distributed around the circumference to produce a relatively large number of interlacing nodes, then the productivity is improved, but the stability and intensity of individual interlacing knots deteriorate

Engineering Contradiction:
Improvenumber of interlacing knots per unit lengthVSAvoidstability of interlacing knots
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by creating non-uniform distribution of nozzle bores around the circumference, with different regions having different numbers of nozzle bores. This allows certain areas to produce more intensive interlacing knots while other areas produce fewer but still adequate knots, thereby maintaining overall knot stability while achieving high productivity. The local concentration of nozzle bores in specific angular ranges creates focused treatment zones that generate stronger knots in those regions.

Inventive Principle:
Principle #3Local quality

2Reliability

If the contact wrap angle of the yarn in the guide groove is increased to ensure intensive knot formation, then the stability of interlacing knots is improved, but the device complexity increases due to more stringent yarn guide arrangement requirements

Engineering Contradiction:
Improveintensity of interlacing knotsVSAvoidarrangement of yarn guides
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by arranging the inlet and outlet yarn guides beforehand to pre-establish the desired contact wrap angle configuration. The yarn guides are positioned such that the yarn naturally follows a path creating sufficient contact wrap around the nozzle ring before entering the treatment zone. This preliminary arrangement ensures that when compressed air is applied, the yarn is already in the optimal position for intensive knot formation, eliminating the need for complex real-time adjustments during operation.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If short opening times are generated at the nozzle bores to produce short and pronounced pressure pulses, then the intensity of interlacing knots is improved, but the use of energy increases due to more frequent pulsing required to achieve the same number of knots

Engineering Contradiction:
Improvepronouncedness of interlacing knotsVSAvoidair consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by creating non-uniform distribution of nozzle bores around the circumference, with different regions having different numbers of nozzle bores. This allows certain areas to produce more intensive interlacing knots while other areas produce fewer but still adequate knots, thereby maintaining overall knot stability while achieving high productivity. The local concentration of nozzle bores in specific angular ranges creates focused treatment zones that generate stronger knots in those regions.

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

This configuration results in the formation of intensive, stable, and uniformly distributed interlacing knots with increased density, suitable for high-speed yarn processing, enhancing knot strength and stability, especially in carpet yarns.

Implementation Method 1

The pressure chamber is connected to a source of compressed air, so that during the interaction of the nozzle bore and the chamber opening, a blast of compressed air is generated in the yarn guide groove of the nozzle ring.

Methodology Applied
Scientific EffectCompressed air: Pressure Gradient

Data Source

PatentEP2646608B1Device and method for producing interweaving knots
Publication Date: 2015.02.25 OERLIKON TEXTILE GMBH & CO KG
  • EP2646608B1 patent drawingFigure 1
  • EP2646608B1 patent drawingFigure 2
  • EP2646608B1 patent drawingFigure 3

AI summary

The invention relates to a device and a method for producing interweaving knots in a multifilament thread. The thread is guided in a circumferential guiding groove of a rotating annular nozzle in contact with the groove base of the guiding ring. The annular nozzle is guided on a stationary stator that has a chamber opening on the circumference, said opening being connected to a pressure chamber. A nozzle bore which opens into the guiding groove is provided within the annular nozzle, said bore interacting with the chamber opening when the annular nozzle rotates in order to generate a pressure impulse in the guiding groove. The thread is guided between an inlet thread guide and an outlet thread guide which are arranged on both sides of the annular nozzle, an opening angle of the chamber opening in the stator and a contact wrap angle of the thread in the guiding groove overlapping. According to the invention, the inlet thread guide and the outlet thread guide are arranged such that the contact wrap angle of the thread in the guiding groove of the annular nozzle is greater than the opening angle of the chamber opening on the stator. Thus, the thread is guided with contact before the pressure impulse is generated, said annular nozzle preferably being driven with a circumferential speed that is lower than the speed of the thread in order to influence the thread tension.