Multi-Ply Paper Embossing with Rubber Roller Nesting

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Solution Overview

Problem

Existing methods for manufacturing paper products with three or more plies, such as toilet paper and kitchen towels, face issues like early wear of steel rollers due to stress and smudging of glue spots, especially when colored glue is used.

Innovation Solution

A method involving embossing and lamination where the middle ply is glued to outer plies without smudging, using a second rubber roller with less pressure to ensure nested alignment and prevent slippage, and employing a cliché roller for precise gluing, allowing for 'pin to pin' or 'DERL' registration of rollers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the three plies are made to pass between two steel rollers that press with sufficient force to join them without glue, then the joining strength is improved, but the steel rollers suffer early wear due to considerable stress

Engineering Contradiction:
Improvejoining strengthVSAvoidroller service life
Core Design Contradiction:
StrengthVSDuration of action of stationary object

Solution Approach 1:

A layer of glue is introduced as an intermediary substance between the plies to facilitate joining. The glue is applied to the middle ply before lamination, allowing the plies to be joined chemically rather than relying solely on mechanical pressure from steel rollers, thereby reducing stress and wear on the rollers while maintaining joining strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Duration of action of stationary object

If the outer plies are joined to the flat middle ply by means of glue spots, then the roller wear is reduced, but slippages of the middle ply cause smudging of the glue spots

Engineering Contradiction:
Improveroller service lifeVSAvoidglue spot alignment
Core Design Contradiction:
Duration of action of stationary objectVSManufacturing precision

Solution Approach 1:

The middle ply is pre-embossed with a pattern of protrusions before glue application. This preliminary embossing creates a textured surface that provides mechanical interlocking with the outer plies, preventing slippage during the lamination process and ensuring proper alignment of glue spots without requiring excessive roller pressure.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If embossing is performed by means of two steel rollers with protrusions and recesses, then the embossing quality is improved, but the steel rollers are subjected to considerable stress

Engineering Contradiction:
Improveembossing qualityVSAvoidroller stress
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The embossing system uses a composite approach combining steel embossing rollers with rubber presser rollers. The steel roller provides the precise embossing pattern through its protrusions, while the rubber roller provides compliant pressure distribution. This composite system maintains embossing quality while reducing stress concentration on the steel roller surface.

Inventive Principle:
Principle #40Composite materials

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 method effectively extends the life of steel rollers and prevents smudging, resulting in a smoother, more aesthetically pleasing product with improved ply alignment and reduced wear on manufacturing equipment.

Implementation Method 1

a second rubber roller (12) which acts on the two plies (2, 4) with less pressure than the first rubber embossing roller (11), so that the plies (2, 4) arrive at lamination, or at gluing, already nested

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The gluing step is performed by means of a cliché roller (13), which is part of an applicator (14)

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

passing the first outer ply through a first steel embossing roller (10), which acts together with a first rubber roller (11), creating the first and second sets of protrusions (21, 22)

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 4

All the plies then pass through a fourth mating roller (17) where they are joined by lamination

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2353859B2Paper product with three or more plies and method for manufacturing it
Publication Date: 2022.03.16 IND CARTARIE TRONCHETTI
  • EP2353859B2 patent drawingFigure 1~2
  • EP2353859B2 patent drawingFigure 3~4
  • EP2353859B2 patent drawingFigure 5~6

AI summary

A method for manufacturing toilet paper, kitchen towels, napkins, handkerchiefs, tissue products in general, with at least three plies, by using two embossing and lamination assemblies of the pin-to-pin, nested, DERL, embossing-gluing type; the system according to the present invention is characterized by the addition of a second rubber embossing roller to the first embossing assembly, which acts on the two plies, an outer ply and a middle ply, with less pressure than the main rubber embossing roller, so that during the subsequent gluing step the two plies are already nested, preventing slippages.