Papermaking Process Control for Wound Roll Convertability

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Solution Overview

Problem

Conventional papermaking processes struggle to produce paper webs with balanced strength, softness, and absorbency, often compromising on strength for increased softness and absorbency, and face challenges in achieving structured paper with uniform density and high caliper using conventional drying methods.

Innovation Solution

A process that involves measuring and manipulating physical properties of the paper web in both machine and cross-machine directions to optimize winding, using a data-driven approach to generate a control algorithm that minimizes variability and improves the formation of convolutely wound rolls with enhanced strength and wicking ability, while maintaining sheet flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional papermaking processes are used to increase softness and absorbency, then softness and absorbency are improved, but strength deteriorates

Engineering Contradiction:

Improvepaper web strengthVSAvoidmanufacturing process complexity

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by measuring and recording physical properties (tensile strength, web stretch, caliper, density) during the papermaking process itself, before the web is converted into final products. This allows real-time adjustment of process parameters to ensure the web has the required strength characteristics early in the manufacturing process, rather than attempting to correct strength issues later during converting operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using measurement data from the papermaking process to generate relationship equations that correlate physical properties with web stretch and other process parameters. This feedback loop allows continuous optimization of the papermaking process to maintain strength while achieving desired softness and absorbency characteristics.

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If conventional drying methods are used to produce structured paper with uniform density, then structural uniformity is improved, but manufacturing precision deteriorates

Engineering Contradiction:

Improvedensity uniformityVSAvoiddrying process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by measuring and recording physical properties during the papermaking process before final drying and converting operations. This allows the web to be prepared with predetermined density and structural characteristics that will carry through subsequent processing, reducing the need for complex corrective operations later.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex mechanical measurement and adjustment systems with data-driven relationship equations that correlate physical properties with process parameters. This substitution allows for more precise control of density uniformity through computational modeling rather than complex mechanical control systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Quantity of substance

If web material is compacted during calendering and converting processes, then density is improved, but thickness deteriorates

Engineering Contradiction:

Improvepaper densityVSAvoidpaper thickness

Core Design Contradiction:

Quantity of substanceVSLength of moving object

Solution Approach 1:

The patent applies preliminary action by measuring and recording caliper and density during the papermaking process itself, before compacting operations. This allows the web to be formed with the correct initial thickness and density characteristics, so that subsequent calendering and converting processes can increase density without excessive thickness reduction.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using measurement data to generate relationship equations that predict how the web will respond to compacting operations. This allows the converting processes to apply the minimum necessary compression to achieve desired density while preserving adequate thickness, rather than applying excessive compaction.

Inventive Principle:

Principle #23Feedback

4Adaptability or versatility

If through-air-drying process is used to produce structured paper, then structural variety and absorbency are improved, but productivity deteriorates

Engineering Contradiction:

Improvestructured paper capabilityVSAvoidpapermaking speed

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by preparing the web with predetermined structural characteristics during the papermaking process itself, before the final drying and converting operations. This allows the web to be formed with the necessary structure for varied products at high speed, and subsequent through-air-drying or other drying methods can complete the process without requiring speed reductions.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9284686B1Process to improve the convertability of parent rolls

Publication Date: 2016.03.15 PROCTER & GAMBLE CO

AI summary

The present disclosure is directed toward a process for adjusting a papermaking process for producing parent rolls of convolutely wound web material having a machine direction (MD) and a cross-machine direction (CD) coplanar and orthogonal thereto that improves the characteristics of the parent rolls of wound web material to improve downstream convertability.