Carding Machine Fiber Feed Control via Dual Chute Pressure

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Solution Overview

Problem

Existing methods for controlling fiber feed to a card lack direct control over lap weight, being influenced by fiber tuft dissolution and product column in the lower chute, leading to inefficiencies in carding quality and production volume.

Innovation Solution

A method and device that regulate fiber feed by dividing the filling chute into upper and lower chutes, using air circulation and pressure control to achieve a specific batting weight, with target values entered by operators and adjusted via algorithms to maintain stable pressure and lap weight, independent of fiber tuft dissolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If pressure control in the lower chute is used to regulate batting weight, then evenness of compaction is improved, but direct control of lap weight is not achieved as it is influenced by fill level, air volume flow, and degree of dissolution

Engineering Contradiction:
Improveevenness of compactionVSAvoiddirect control of lap weight
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements a feedback control system where the actual lap weight is measured and compared with the target lap weight, and the pressure in the lower chute is adjusted accordingly to achieve the desired lap weight. This closes the control loop, allowing direct regulation of lap weight rather than indirect control through fill level or air flow.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the controlled parameter from fill level or air flow to pressure in the lower chute, which is directly linked to lap weight. By controlling the pressure parameter directly, the system achieves both even compaction and direct lap weight control.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If fill level or air quantity is changed to adjust lap weight, then lap weight can be modified, but the control is indirect and influenced by multiple variables including dissolution degree

Engineering Contradiction:
Improvelap weightVSAvoidcontrol system complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The feedback control system continuously monitors actual lap weight and adjusts pressure in the lower chute accordingly, providing direct control of lap weight while simplifying the control approach by focusing on a single key parameter (pressure) rather than multiple variables.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent identifies pressure in the lower chute as the critical parameter controlling lap weight, and changes the control strategy to directly regulate this parameter, thereby simplifying the control system while achieving precise lap weight control.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If fiber tufts are fed continuously or as required, then production flexibility is maintained, but pressure fluctuations in the upper duct disturb conditions in the lower duct

Engineering Contradiction:
Improveproduction flexibilityVSAvoidpressure stability in lower chute
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The filling chute is divided into an upper chute and a lower chute, separating the functions of receiving fiber tufts (upper) and forming homogeneous batting (lower). This segmentation isolates the lower chute from pressure fluctuations in the upper duct, maintaining stable conditions for batting formation while allowing flexible production.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lower chute acts as an intermediary zone that decouples the upper and lower shaft systems. By controlling pressure independently in the lower chute, the system filters out disturbances from the upper duct while maintaining production flexibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables precise control of lap weight and pressure in the carding process, improving carding quality and production efficiency by stabilizing the pressure and weight of the batting, thus enhancing the evenness and quality of the card sliver or fleece produced.

Implementation Method 1

Air is fed in via a fan in the lower chute, which leads to an increase in pressure over the fiber tufts

Methodology Applied
Scientific EffectPressure increase: Pressure Increase

Implementation Method 2

The fiber tufts are compacted in the lower chute under a specific pressure to form a batting with a specific batting weight

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

The air fed in is discharged from the lower shaft via an air-permeable wall and fed back to the fan

Methodology Applied
Scientific EffectAir circulation: Convection

Data Source

PatentEP2867392B1Method and device for controlling the fiber feed to a carding machine
Publication Date: 2018.10.10 MASCHINENFABRIK RIETER AG
  • EP2867392B1 patent drawingFigure 1
  • EP2867392B1 patent drawingFigure 2

AI summary

The invention relates to a device and a method for controlling the fiber feed to a carding machine having a filling shaft. The filling shaft is divided into an upper shaft and a lower shaft, wherein fiber flocks are fed into the upper shaft and are transported into the lower shaft (5) by means of a feeding device (19). The fiber flocks are compressed into wadding having a certain wadding weight in the lower shaft under a certain pressure. A target value for the wadding weight is predefined, with which target value a pressure for the lower shaft is associated. Then an actual value of the wadding weight is determined and the target value for the pressure is corrected on the basis of a comparison of the target value and actual value of the wadding weight.