Surface Rewinder Belt Nest for High-Speed Low-Firmness Logs

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Solution Overview

Problem

Existing rewinding systems face challenges in winding low firmness, large diameter products at high speeds without excessive log vibration, which leads to defects and operational issues, and require systems that are tolerant of web material variations without requiring specialized operator adjustments.

Innovation Solution

A rewinding apparatus using a belt in conjunction with a winding drum forms a winding nest, where the belt's surface velocity is varied cyclically relative to the drum's velocity to control log advancement, winding, and discharge, and incorporates rider rolls and core chucks to manage log diameter and support, reducing nip pressure and interlayer slip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If surface winder is used to wind high firmness, low bulk logs, then firmness is improved, but low firmness, large diameter products cannot be produced at high speeds due to excessive log vibration

Engineering Contradiction:

Improvelog firmnessVSAvoidwinding speed

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The patent applies dynamics by making the belt speed variable rather than constant. The belt speed is dynamically adjusted during the winding cycle to match the log speed, creating a speed profile that prevents excessive log vibration while maintaining high winding speeds for large diameter, low firmness products

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the speed parameter of the belt relative to the log. By varying the belt speed as a parameter rather than keeping it fixed, the system can adapt to different log sizes and firmness levels, enabling high-speed winding of large diameter products without excessive vibration

Inventive Principle:

Principle #35Parameter changes

2Strength

If center winder is used to wind low firmness, high bulk logs, then low firmness products are improved, but high speeds cannot be achieved due to excessive log vibration from slender mandrel

Engineering Contradiction:

Improvelog firmnessVSAvoidwinding speed

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The patent extracts the mandrel from the center winder configuration and replaces it with a surface winder using a belt. This removes the source of excessive vibration (the slender mandrel) while maintaining the ability to wind low firmness, high bulk logs at high speeds

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a belt as an intermediary between the drive system and the log. This belt mediator provides the necessary drive force without the vibration problems of a mandrel, enabling high-speed winding of low firmness products

Inventive Principle:

Principle #24Intermediary (Mediator)

3Strength

If high web tension is applied in center winder to produce firm log, then log firmness is improved, but web blowouts and tearing occur due to bursting of perforations

Engineering Contradiction:

Improvelog firmnessVSAvoidweb blowouts and tearing

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the tension-based firming mechanism of center winders with a friction-based belt drive system. This substitution eliminates the need for high web tension, preventing web blowouts and tearing while still producing firm logs through the belt's frictional engagement with the log surface

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If surface winder operates at high speed with large diameter logs, then productivity is improved, but excessive log vibration causes winding defects and operational problems

Engineering Contradiction:

Improvewinding speedVSAvoidlog vibration

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent uses feedback by continuously monitoring log speed and using this information to adjust belt speed. This closed-loop control prevents excessive vibration by ensuring the belt and log speeds are properly synchronized throughout the winding process

Inventive Principle:

Principle #23Feedback

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

Enables high-speed winding of low firmness, large diameter logs with reduced vibration and defects, maintaining web thickness and structure integrity, and operates robustly with minimal operator intervention.

Implementation Method 1

the surface speed of the belt, relative to the winding drum, is used to control the logs during the introduction, winding, and discharge phases

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS12600590B2Surface rewinder with center assist and belt and winding drum forming a winding nest

Publication Date: 2026.04.14 BW CONVERTING INC

AI summary

A rewinding machine winds a web material into a log about a core. The web material to be wound is directed about a rotating winding drum. A continuous loop is spaced from the winding drum and with the winding drum defines a nip through which the core is inserted and through which the web material is directed. A surface of the continuous loop opposite the winding drum across the nip is configured to move in a direction generally opposite of the winding drum for winding the web material about the core. A rider roll defines a winding space with the winding drum and the continuous loop. The rider roll is movable relative to the continuous loop and the winding drum to allow for an increase in a diameter of the log in the winding space during winding of the web material about the core.