Oriented Polymer Release Composite for Curling Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing release paper composites face issues with curling and swelling due to moisture penetration, leading to edge waviness and increased waste and handling costs, with thick composites being necessary to mitigate these issues but resulting in reduced roll length and surface quality.

Innovation Solution

The use of oriented polymers for cover layers and a lightweight core layer with a basis weight of up to 150 g/m², such as biaxially oriented polyethylene terephthalate or polypropylene, to enhance rigidity and reduce moisture absorption, along with a silicone coating for release properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a relatively voluminous paper with a basis weight of more than 100 g/m² is used to counteract swelling and curling, then edge stability is improved, but the composite becomes thicker and surface quality deteriorates due to visible paper texture

Engineering Contradiction:
Improveedge stabilityVSAvoidsurface quality
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the basis weight of the paper core layer to be between 40-150 g/m², optimizing it to prevent excessive swelling and curling while avoiding the thickness and surface texture problems of heavier papers. This parameter optimization resolves the contradiction between edge stability and surface quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite structure consisting of a paper core layer laminated between two polyethylene cover layers. This composite material design allows the thin paper core (40-150 g/m²) to provide dimensional stability while the polyethylene cover layers provide a smooth surface finish, thus achieving both edge stability and high surface quality simultaneously.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If thin polyethylene layers are used to achieve a smooth surface, then surface quality is improved, but moisture penetration increases causing more swelling and curling

Engineering Contradiction:
Improvesurface qualityVSAvoidmoisture penetration
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent employs a composite material structure where thin polyethylene cover layers (each 1-10 μm) are laminated onto a paper core layer. This composite design allows the polyethylene layers to provide a smooth surface finish while the paper core layer acts as a moisture barrier, preventing excessive moisture penetration that would cause swelling and curling, thus resolving the contradiction between surface quality and moisture resistance.

Inventive Principle:
Principle #40Composite materials

3Productivity

If the core layer basis weight is reduced to make the composite thinner, then productivity is improved through longer rolls, but edge stability deteriorates due to increased curling and swelling

Engineering Contradiction:
Improveroll lengthVSAvoidedge stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent optimizes the paper core layer basis weight to a specific range of 40-150 g/m², which is thin enough to enable longer rolls and higher productivity, yet heavy enough to maintain adequate edge stability and resist excessive curling and swelling. This parameter optimization resolves the contradiction between productivity and edge stability.

Inventive Principle:
Principle #35Parameter changes

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 approach results in a cost-effective, thin release paper composite with improved surface quality and reduced curling tendencies, allowing for higher web speeds and increased temperature resistance, thus enhancing processing efficiency and product quality.

Implementation Method 1

the core layer is designed in such a way that the fiber material used has a basis weight of at most 150 g/m²

Methodology Applied
Scientific EffectMoisture resistance:

Implementation Method 2

at least the first cover layer having an external coating made of a release agent

Methodology Applied
Scientific EffectRelease properties:

Implementation Method 3

an oriented polymer is used for the cover layers instead of the polyethylene usually used in practice to enhance rigidity

Methodology Applied
Scientific EffectOrientation:

Data Source

PatentEP3323606B1Separation composite
Publication Date: 2020.07.08 MONDI AG
  • EP3323606B1 patent drawingFigure 1
  • EP3323606B1 patent drawingFigure 2
  • EP3323606B1 patent drawingFigure 3

AI summary

A release composite for receiving a removable adhesive membrane, comprising a first and a second cover layer (1, 2) and a core layer (3) made of a fiber material laminated between the two cover layers (1, 2), wherein at least the first cover layer (1) has an outer coating (7) made of a release material. The release composite is characterized in that the cover layers (1, 2) each consist of an oriented polymer film and that the core layer (3) has a basis weight of at most 150 g/m².