Card Wire Undercut Teeth for Condenser Roller Fiber Web Uniformity

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Solution Overview

Problem

Existing card wires on condenser rollers for nonwoven cards often result in an irregularly undulating appearance of fiber webs and fiber loading, due to the condensation process affecting fiber orientation and distribution.

Innovation Solution

A card wire design featuring a rib portion with teeth inclined at an angle, having a front and back portion that join at the tip, and incorporating multiple undercut segments with varying angles and positions, which helps to reorient fibers and prevent irregular undulations by creating a channelling effect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional card wires with large height and tooth depth are used on condenser rollers, then the fiber web condensation capacity is improved, but irregular undulating appearance and fiber loading occur on the fiber web

Engineering Contradiction:
Improvefiber web condensation capacityVSAvoidfiber web surface uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention changes the geometric parameters of the card wire teeth by introducing undercut segments with specific angles (first undercut angle and second undercut angle) and dimensions (first and second distances from tip). These parameter modifications transform the tooth profile from conventional straight or simple curved shapes to complex undercut profiles that effectively channel and redistribute fibers during condensation, eliminating the undulating appearance while maintaining condensation capacity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The tooth front portion is segmented into multiple sections including the first and second undercut segments at different positions and angles. This segmentation allows each segment to perform specific functions: the first undercut segment handles initial fiber redirection while the second undercut segment refines fiber distribution, collectively solving the surface uniformity problem during the condensation process

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If card wires with large pitch between teeth are used to accommodate fiber web amount, then the fiber accommodation capacity is improved, but fiber orientation control and web uniformity deteriorate

Engineering Contradiction:
Improvefiber accommodation capacityVSAvoidfiber orientation control
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The invention modifies the tooth profile parameters by adding undercut segments with specific geometric characteristics (angles and distances) that enhance fiber interaction. This allows the card wire to effectively manage larger fiber quantities through improved channeling and redistribution mechanisms, thereby maintaining fiber orientation control even with larger pitch between teeth

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3097223B1Card wire, an apparatus comprising a condenser roller which is covered with said card wire and method of operating said apparatus
Publication Date: 2019.08.07 GROZ BECKERT KG
  • EP3097223B1 patent drawingFigure 1
  • EP3097223B1 patent drawingFigure 2
  • EP3097223B1 patent drawingFigure 3

AI summary

The card wire(105)comprises a plurality of teeth inclined at an angle with the rib portion(103). The teeth have a front portion(107)and a back portion(109)joining at the tip of the teeth(111); and a base segment (113) connecting the front portion to the back portion of the preceding tooth. The front portion is the inner portion of the tooth leaning towards the rib portion. The back portion is the outer portion of the tooth. The front portion comprises at least two undercut segments(120, 130). The second undercut segment is spaced further away from the tip of the tooth than the first undercut segment. Each undercut segment has an undercut angle, being the minimum of the angles with the longitudinal direction of the card wire, of the tangents to each point of the part of the undercut segment going -when observed from the tip -inwards from the front portion. The second undercut segment has a larger undercut angle than the first undercut segment.