Cross-lapper Shroud Belt Deflection Roller Centrifugal Force Control

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Solution Overview

Problem

Existing crosslapper devices face issues with product quality due to fluctuating centrifugal forces affecting the web during deflection, leading to disturbances in the pile structure.

Innovation Solution

The introduction of a shroud guided around a partial circumference of the first deflection roller within the upper carriage, along with a further deflection roller to maintain the web's press and minimize exposure to centrifugal forces, and the use of sensors to synchronize belt speeds and adjust the gap between rollers for consistent tension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the web is guided around a deflection roller in a moving upper carriage, then the laying process can be performed, but the web is exposed to fluctuating centrifugal forces that disturb the pile structure

Engineering Contradiction:
Improvelaying process capabilityVSAvoidpile structure quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

A shroud belt is introduced as an intermediary element between the infeed belt and the deflection roller. The shroud belt runs together with the infeed belt around a partial circumference of the deflection roller, providing continuous coverage and protection of the web during deflection, thereby reducing exposure to harmful centrifugal forces while maintaining the laying process capability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The shroud belt provides localized protection only in the critical deflection area where centrifugal forces are most harmful. The shroud covers the web around a partial circumference of the deflection roller, precisely where needed, without requiring complete enclosure of the entire laying mechanism, thus balancing protection with operational efficiency

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the shroud runs together with the infeed belt around the deflection roller, then the web is protected from centrifugal forces, but the device complexity increases

Engineering Contradiction:
Improvepile structure qualityVSAvoidnumber of belts and rollers
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The shroud belt serves multiple functions: it protects the web from centrifugal forces during deflection, maintains proper web alignment, and works in coordination with the infeed belt and deflection roller. This multi-functionality justifies the addition of the shroud belt by providing several benefits from a single added component

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The coverage of the deflection roller is segmented into two parts: the portion covered by both the infeed belt and shroud belt where the web is protected, and the remaining portion where the web runs uncovered. This segmentation allows protection only in the critical area while minimizing the complexity of the overall system

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

This solution ensures the web is held firmly during deflection, reducing disturbances and improving product quality by minimizing the impact of centrifugal forces and maintaining consistent belt speeds, resulting in a more stable pile formation.

Implementation Method 1

The pile is held between the infeed and cover belts

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The centrifugal forces acting on the pile increase with the square of the respective circumferential speed

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2635727B1Cross-lapper
Publication Date: 2015.05.20 TRUETZSCHLER NONWOVENS GMBH
  • EP2635727B1 patent drawingFigure 1
  • EP2635727B1 patent drawingFigure 2
  • EP2635727B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a cross-lapper and to a method for forming a nonwoven fabric made of a plurality of pile layers, consisting of an continuously revolving feed belt (E), a counter belt (D) continuously revolving at the same speed in the opposite direction, as well as an additional counter belt (G), wherein the pile (F) to be laid is first conveyed between a feed belt and cover belt (E, D) to a movable upper carriage (OW), which comprises a first deflection roller (O) for the feed belt (E), and is transferred there to the counter belt (G), wherein the feed and counter belts (E,G) are guided around two adjacent laying rollers (LE, LG) of a laying carriage (LW) which form a laying gap, and the laying carriage (LW) is movably mounted transversely to and above a discharge belt (AB) receiving the nonwoven fabric to be laid and moves back and forth periodically. According to the invention, the cover belt (D) is guided jointly with the feed belt (E) around a partial circumference of the first deflection roller (O).