Buffer Device Decouples Pulsating Infeed From Constant Outfeed

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Solution Overview

Problem

Existing methods for transferring folded fibrous webs to downstream machines often result in distortion and creasing due to pulsating speeds, leading to suboptimal quality and efficiency, especially at high speeds and with large card working widths.

Innovation Solution

A storage table with an endless belt that decouples the outfeed belt speed from the infeed speed of the storage table, ensuring the belt always moves at a positive speed and reducing pulsating sag, allowing for synchronized movement with the laying carriage's speed profile to minimize distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the take-off table is decelerated and accelerated in sync with the laying carriage to prevent curved laying, then the laying quality is improved, but the feed speed to downstream machines becomes non-constant

Engineering Contradiction:
Improvelaying qualityVSAvoidfeed speed constancy
Core Design Contradiction:
Manufacturing precisionVSSpeed

Solution Approach 1:

A storage table with an endless belt is introduced as an intermediary device between the take-off table and downstream machines. The storage table receives material at pulsating speed from the take-off table and delivers it at constant speed to downstream machines, decoupling the speed profiles of the two sides and resolving the contradiction between laying quality and feed speed constancy

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The conveying system is segmented into distinct functional zones: the take-off table handles pulsating speed for laying quality, the storage table with endless belt acts as a buffer zone, and the downstream delivery handles constant speed. This segmentation allows each zone to optimize for its specific function without compromising the other

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the endless belt is driven at inlet coupled to the speed profile of the layer, then the distortion of folded fiber pile is reduced, but the system complexity increases

Engineering Contradiction:
Improvefiber pile integrityVSAvoiddrive system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The drive system at the inlet of the storage table is made dynamic by coupling it to the speed profile of the laying carriage. This allows the belt speed to adapt continuously to the pulsating motion of the laying carriage, minimizing distortion of the folded fiber pile while maintaining synchronization with the laying process

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The drive system incorporates feedback from the laying carriage speed profile to continuously adjust the inlet belt speed. This feedback mechanism ensures that the storage table responds dynamically to changes in the laying process, maintaining fiber pile integrity without requiring complex manual intervention

Inventive Principle:
Principle #23Feedback

3Productivity

If high delivery speeds are used to increase productivity, then the production efficiency is improved, but the pulsating sag increases causing distortion

Engineering Contradiction:
Improvedelivery speedVSAvoidweb distortion
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The storage table with endless belt serves as a mediator that absorbs the pulsating motion generated by high-speed delivery. By decoupling the delivery speed from the laying speed, the system can operate at high productivity while the storage table compensates for pulsating sag, preventing distortion of the nonwoven web

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3360990B1Method for operating a buffer device for a non-woven web-laying device
Publication Date: 2023.08.02 TRUETZSCHLER GRP SE
  • EP3360990B1 patent drawingFigure 1
  • EP3360990B1 patent drawingFigure 2
  • EP3360990B1 patent drawingFigure 3

AI summary

The invention relates to a storage table for a nonwoven fabric layer with a layer that lays down a folded fiber pile onto an outfeed conveyor (15), wherein the storage table (20) has an endless belt (21) that receives the folded fiber pile from the outfeed conveyor (15) at a pulsating speed (v22) and delivers it at a constant speed (v23) to a downstream machine for further processing or consolidation of the folded fiber pile. The invention further relates to a method for operating a storage table. The invention is characterized in that the endless belt (21) of the storage table (20) is driven at the infeed by a first drive and at the outfeed by a second drive, wherein the first drive is coupled to the movement and speed profile of the layer.