Adjustable Dewatering Foil Blades for Fiber Orientation Control

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Solution Overview

Problem

Existing papermaking technologies, such as the Fourdrinier machine, lack effective control over fiber orientation and drainage rates during the dewatering process, which significantly impacts paper strength and uniformity, particularly beyond a dryness level of 1.5%, and fail to precisely manipulate fiber orientation for optimal strength properties.

Innovation Solution

A method and machine that utilize adjustable angle and height dewatering foil blades and vacuum levels from 0.1% to 5% dryness on the Fourdrinier dewatering table, in conjunction with headbox shear forces, to control fiber orientation and turbulence, allowing for precise manipulation of fiber alignment in either the machine or cross-machine direction for enhanced paper strength and quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional Fourdrinier dewatering is used, then paper production is achieved, but fiber orientation control and drainage rate control are insufficient, resulting in poor paper strength and uniformity

Engineering Contradiction:

Improvefiber orientation controlVSAvoiddewatering system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The dewatering system is segmented into multiple independent zones (initial sheet dewatering zone, intermediate dewatering zone, final dewatering zone) along the Fourdrinier table. Each zone has independently adjustable foil blades with controllable angles and heights, allowing precise local control of drainage rates and turbulence levels to manipulate fiber orientation throughout the dewatering process

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The foil blades are made dynamically adjustable during operation through computer-controlled mechanisms that can change blade angles and heights in real-time. This dynamic adjustment capability allows the system to optimize fiber orientation control for different paper grades and production conditions without requiring physical reconfiguration

Inventive Principle:

Principle #15Dynamics

2Productivity

If drainage rate is increased to improve production efficiency, then productivity increases, but fiber orientation control deteriorates

Engineering Contradiction:

Improvedewatering rateVSAvoidfiber orientation uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

Different zones of the dewatering system are assigned different local qualities - the initial zone uses high drainage rates with specific blade configurations for rapid water removal, while subsequent zones use adjusted blade angles and heights to control turbulence and fiber orientation. This allows high productivity overall while maintaining precise fiber orientation control in each local zone

Inventive Principle:

Principle #3Local quality

3Stability of the object's composition

If turbulence is increased to prevent fiber entanglement, then fiber mobility improves, but fiber orientation control becomes difficult

Engineering Contradiction:

Improvefiber mobilityVSAvoidfiber orientation control

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The system applies periodic variations in turbulence through sequentially activated foil blades at different angles and heights as the paper web moves through the dewatering zones. This periodic action maintains fiber mobility and prevents entanglement while progressively guiding fibers into desired orientations through controlled turbulence patterns in each zone

Inventive Principle:

Principle #19Periodic action

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 approach results in improved paper strength characteristics, including Mullen, Burst, Bending Stiffness, and Ring Crush, as well as enhanced formation, smoothness, and printability, by carefully managing fiber orientation and drainage across the entire dewatering process, producing higher quality paper.

Implementation Method 1

vacuum assisted drainage elements

Methodology Applied

Scientific EffectVacuum: Vacuum

Implementation Method 2

produce a high amount of turbulence in this paper dryness zone (0.1% to 2%). This keeps the fibers mobile and prevents entanglement

Methodology Applied

Scientific EffectTurbulence: Turbulence

Implementation Method 3

The headbox controls fiber orientation through a speed difference between its stock jet speed and the dewatering fabric speed

Methodology Applied

Scientific EffectShear stress: Shear Stress

Data Source

PatentUS9951471B2Method and machine for manufacturing paper products using fourdrinier forming

Publication Date: 2018.04.24 IBS OF AMERICA CORP

AI summary

An improved method for producing paper from pulp includes a plurality of subassemblies arranged in the forming or wet section of a Fourdrinier. The Fourdrinier includes a dewatering table having a plurality of blades that are static and on-the run adjustable in height and/or angle to control orientation of paper fibers in the stock to create a superior quality of paper and improved paper strength characteristics. Gravity and vacuum assisted drainage elements are equipped with on-the-run adjustable angle and height dewatering foil blades starting from a paper dryness of 0.1% and extending all the way to 5% dryness. The result of this process and machine is to improve the paper quality, save fibers and chemicals and fulfill the required paper properties.