Energy-Absorbing Winding Core Structure for Controlled Collapse

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Solution Overview

Problem

Conventional winding cores collapse abruptly and are insufficient in absorbing roll strain energy, leading to excessive inside diameter reduction and vibration issues, especially when handling materials wound under high tension.

Innovation Solution

A winding core design featuring a cylindrical structure with a radially inner shell, an outer shell, and an energy-absorbing zone formed by collapsible layers with three-dimensional structured atomic regions that absorb and distribute pressure, allowing controlled collapse over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If conventional corrugated paperboard layers are used in winding cores, then the core can immediately relieve some radially inward compression, but the core collapses too abruptly and causes high vibration during rotation

Engineering Contradiction:
Improveradial compression reliefVSAvoidcore stability during rotation
Core Design Contradiction:
ForceVSStability of the object's composition

Solution Approach 1:

The patent changes the geometric parameters of the collapsible structure by using polyhedral cells with specific face configurations (e.g., octagonal prisms, hexagonal prisms) instead of conventional corrugated layers. This structural parameter change allows the core to collapse in a more controlled, progressive manner rather than abruptly, reducing vibration while maintaining compression relief capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a dynamic collapse behavior where the polyhedral cellular structure progressively collapses under radial load through controlled buckling of its faces and edges. This dynamic response allows the core to adapt to varying compression forces over time, providing sustained compression relief without sudden collapse that would cause vibration

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If prior-art radially compressible regions are used, then some roll strain energy can be absorbed, but the structure does not have sufficient capacity to absorb large pressure from high-tension winding

Engineering Contradiction:
Improveroll strain energy absorptionVSAvoidpressure absorption capacity
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The patent employs composite construction by combining polyhedral cellular structures with core wall materials (such as paperboard or plastic) to create a composite core structure. This composite approach integrates the energy-absorbing characteristics of the cellular geometry with the structural strength of the core material, enabling sufficient capacity to absorb large pressures from high-tension winding while maintaining overall structural integrity

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes a porous-like polyhedral cellular structure within the core wall that provides void spaces for energy absorption. This cellular geometry creates a controlled porous structure that can compress and collapse to absorb roll strain energy, while the surrounding core material maintains structural strength to handle high-tension winding pressures

Inventive Principle:
Principle #31Porous materials

3Manufacturing precision

If the core wall is made stronger to resist compression, then ID comedown is reduced, but the core cannot adequately absorb roll strain energy from high-tension winding

Engineering Contradiction:
Improveinside diameter stabilityVSAvoidroll strain energy absorption
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The patent applies local quality by creating zones of different structural properties within the core wall. The polyhedral cellular regions provide localized energy absorption capacity where needed, while other portions of the core wall maintain higher strength to preserve inside diameter stability. This spatial variation in structural quality allows the core to simultaneously manage compression and absorb energy

Inventive Principle:
Principle #3Local quality

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

The design significantly reduces inside diameter reduction and length growth, improving core stability and material efficiency by effectively managing roll strain energy and maintaining core integrity under prolonged pressure.

Implementation Method 1

the roll of wound material stores energy referred to herein as 'roll strain energy' because of the tension under which the film is wound around the core and/or because of the shrinkage of the material after winding

Methodology Applied
Scientific EffectRoll strain energy: Elasticity

Implementation Method 2

the compressive load from the roll also causes the core to grow in length

Methodology Applied
Scientific EffectRadially inward pressure: Compression

Data Source

PatentEP2244964A1Winding cores for material rolls having high roll strain energy, and method for making same
Publication Date: 2010.11.03 SONOCO DEVELOPMENT INC

AI summary

Winding cores for elastically stretched or shrinkable materials are designed to significantly reduce the amount of roll strain energy developed during winding. This is accomplished by building into the core an energy-absorbing zone (220) that can be collapsed by a substantial amount and in a relatively controlled fashion over a substantial period of time under the influence of a continued radially inward pressure exerted by the roll of wound material. The energy-absorbing zone is formed by one or more collapsible layers (100) having repeated atomic regions (105) projecting out of a plane of the sheet and each defining a plurality of normal vectors (108a, 108b, 108c, 108d) in different sub-regions of the atomic region, wherein the normal vectors, when projected onto the two-dimensional plane of the sheet, are in a plurality of different directions in the plane.