Suction Tube Centered Opening Reduces Fiber Lodging

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Solution Overview

Problem

Existing suction tube assemblies in nonwoven mat wet forming machines experience fiber lodging issues, leading to reduced productivity and uneven mat quality due to the design of exit tubes communicating with primary suction tubes through spaced rectangular openings, causing central fouling that requires machine shutdown for cleaning.

Innovation Solution

The suction tube assembly design is improved by replacing the two spaced rectangular openings with a single, centered opening for the exit tube to communicate with the primary suction tube, resulting in reduced fiber accumulation and easier cleaning, particularly with a primary suction tube slot length of at least 3.6 meters and an exit tube opening aligned with the centerline, enhancing operational efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two spaced rectangular openings are used for exit tube communication, then structural stability is improved, but fiber accumulation occurs in the center portion requiring shutdown for cleaning

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidcleaning accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent inverts the conventional positioning approach by moving from spaced openings at edges to a single centered opening. This inversion places the opening in the center portion of the suction tube, which becomes accessible from the sides while maintaining structural integrity, thereby eliminating fiber accumulation issues and enabling continuous operation.

Inventive Principle:
Principle #13The other way round (Inversion)

2Productivity

If machine speed is increased to increase productivity, then output is improved, but fiber lodging in suction slots occurs more frequently

Engineering Contradiction:
Improvemat production rateVSAvoidcontinuous operation capability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent extracts the harmful factor (fiber accumulation) by redesigning the opening configuration to prevent fiber lodging. The single centered opening design eliminates the trap zones that occur with spaced openings, allowing the system to operate continuously at high speeds without fiber buildup interfering with suction tube function.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If suction tube slot length is increased to handle wider forming wires, then processing capability is improved, but fiber accumulation in central portion increases

Engineering Contradiction:
Improveforming wire width compatibilityVSAvoidfiber accumulation
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies inversion by repositioning the opening to the center of the suction tube. This allows the slot length to be extended for wider forming wires while the centralized opening prevents fiber accumulation by eliminating the dead zones that occur with edge-positioned openings in long slots.

Inventive Principle:
Principle #13The other way round (Inversion)

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 design significantly reduces fiber accumulation in the suction slot, allowing for continuous operation without shutdowns for cleaning, maintaining consistent mat quality and increasing productivity by preventing central fouling, especially in wider forming wire systems.

Implementation Method 1

Excess water is removed from the slurry on the forming wire using one or more suction tube assemblies located beneath the moving forming wire

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP1939351B1Suction tube for nonwoven mat machine and method
Publication Date: 2011.09.07 JOHNS MANVILLE CORP
  • EP1939351B1 patent drawingFigure 1
  • EP1939351B1 patent drawingFigure 2~4
  • EP1939351B1 patent drawingFigure 5~7

AI summary

A nonwoven fibrous mat or web forming or treating system is disclosed comprising a movable, permeable wire or belt for carrying the fibrous mat or web over at least one suction tube assembly comprising a primary suction tube (84) having a suction slot (92) at the top of the primary suction tube and an exit tube (86) communicating with the primary suction tube mounted beneath the permeable belt to have the suction slot on or close to the bottom surface of the movable belt. The suction slot is at least 3.6 meters long and up to more than 5.3 meters long, and the exit tube of the suction tube assembly communicates with the primary suction tube through an opening (96) in the primary suction tube, the opening being generally centered around a centerline (97) of the suction slot. This primary suction tube assembly provides a more uniform suction distribution along the suction slot and reduces fouling of the suction slot compared with previous suction tube assemblies.