Interlocking Slit Paper Layers for Void Filling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing paper packaging materials, such as pleated paper and bubble wrap, face challenges in providing effective cushioning and void filling while being recyclable, with prior art materials often requiring machinery for expansion and using non-recyclable plastics or having limited thickness due to nesting issues.

Innovation Solution

A novel paper product comprising multiple slit sheet layers with differing slit patterns that interlock upon expansion, creating a three-dimensional open netting structure with varying angles of inclination, maximizing thickness and preventing nesting, thus enhancing cushioning and recyclability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If multiple layers of expanded paper are used to increase thickness and cushioning, then cushioning performance is improved, but the layers tend to nest together reducing the effective thickness

Engineering Contradiction:
Improvecushioning performanceVSAvoideffective thickness
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

The patent applies asymmetry by creating expanded paper layers with non-parallel land areas at different angles. Each layer has land areas inclined at specific angles (e.g., 30-60 degrees from vertical), and adjacent layers are oriented with different angles so that the land areas do not align parallel to each other. This angular asymmetry prevents the layers from nesting together completely, maintaining the thickness of the multi-layer structure while providing enhanced cushioning performance.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent intentionally designs a controlled nesting system where land areas of adjacent layers partially interlock at angles. Rather than completely preventing nesting, the invention allows limited nesting at controlled angles to create an interlocking structure that maintains thickness. The angled land areas nest into each other in a controlled manner that prevents complete collapse while maximizing space utilization and cushioning effectiveness.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Strength

If plastic bubble wrap is used for cushioning, then cushioning performance is improved, but recyclability deteriorates

Engineering Contradiction:
Improvecushioning performanceVSAvoidrecyclability
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent changes the fundamental material parameter from plastic to expanded paper, transforming the material composition while maintaining the cushioning function. The expanded paper structure, with its air-filled cells and land areas, provides cushioning performance comparable to plastic bubble wrap. This parameter change enables recyclability since paper is biodegradable and easily recyclable, eliminating the harmful environmental factors associated with plastic disposal.

Inventive Principle:
Principle #35Parameter changes

3Strength

If slit sheet material is expanded to create three-dimensional structure, then cushioning is improved, but machinery is required for expansion

Engineering Contradiction:
ImprovecushioningVSAvoidexpansion machinery
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-slitting the paper into specific patterns (such as hexagonal or other geometric configurations) before expansion. The slitting creates predetermined weak points and structural features that guide the expansion process. This preliminary preparation allows the material to expand into its three-dimensional cushioning structure more easily, reducing the complexity of the expansion machinery needed while maintaining effective cushioning performance.

Inventive Principle:
Principle #10Preliminary 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

The interlocking slit sheet packaging material provides improved cushioning and void filling capabilities, maintains thickness under load, and is more resistant to deformation, while being recyclable and easier to use without the need for additional machinery or separator sheets.

Implementation Method 1

Each layer expands to create a three dimensional open netting of cells

Methodology Applied
Scientific EffectAir pressure expansion: Pressure Increase

Data Source

PatentEP3683166A1Method of producing at least a pair of interlocking adjacent layers of a paper packaging product
Publication Date: 2020.07.22 GOODRICH DAVID PAUL
  • EP3683166A1 patent drawingFigure 1~8
  • EP3683166A1 patent drawingFigure 2~4
  • EP3683166A1 patent drawingFigure 5

AI summary

The invention relates to a method of producing at least a pair of interlocking adjacent layers of a paper packaging product, wherein each of said pair of interlocking adjacent layers is formed of an expanded sheet of slit paper, and comprises cells that include land regions that are inclined with respect to the plane of the unexpanded paper sheet. The method comprises the steps of: slitting an unexpanded paper sheet to produce slits that upon expansion, produce land regions having angles of inclination in the range 50 to 85 degrees, said step of slitting comprising slitting with "V" shaped cutting blades, wherein each cutting blade has a difference in bevel angle on the two sides of the cutting blade and produces a difference in wedge effect on the two edges of a slit, expanding said sheet of slit paper, and layering said expanded sheet on another expanded sheet, and causing the land regions of said adjacent layers of expanded sheet to interlock over substantially the entire length of the layers.