Laminating Polyester Film to Metal Strip

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Solution Overview

Problem

Machine direction oriented (MDO) polyester films are prone to wrinkling and creasing during lamination processes, leading to defective products and high rejection rates, while biaxially oriented films are more expensive and inflexible, and require significant capital expenditure for production.

Innovation Solution

Applying a specific combination of film tension and process line speed to MDO polyester films before the lamination nip, with tension in the longitudinal direction of the film prior to entering the nip, effectively preventing wrinkling and creasing, and allowing for flexible production with relatively inexpensive equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If machine direction oriented (MDO) polyester films are used in lamination processes, then production costs are reduced and equipment flexibility is improved, but the films are prone to wrinkling and creasing during processing

Engineering Contradiction:
Improveproduction cost and equipment flexibilityVSAvoidfilm stability during lamination
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies a specific tension range (0.1-5.0 N/cm, preferably 0.3-3.0 N/cm) to the MDO film before lamination, and controls the lamination temperature within a specific range (80-120°C). These parameter changes stabilize the highly anisotropic film structure, preventing wrinkling and creasing while maintaining the use of cost-effective MDO films instead of expensive biaxially oriented films.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If biaxially oriented films are used in lamination processes, then film stability and dimensional stability are improved, but production costs increase and equipment flexibility decreases

Engineering Contradiction:
Improvefilm stability during laminationVSAvoidproduction cost and equipment flexibility
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the processing parameters specifically for MDO films by applying a controlled tension (0.1-5.0 N/cm) and using a specific lamination temperature range (80-120°C). This allows MDO films to achieve the same stability as expensive biaxially oriented films, eliminating the need for costly pre-oriented films while maintaining manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies tension to the MDO film in advance, before the lamination step, to pre-stabilize the highly anisotropic film structure. This preliminary action prevents wrinkling and creasing during subsequent processing, allowing the use of flexible MDO films without sacrificing dimensional stability.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If MDO films are used without specific tension control, then equipment simplicity is maintained, but wrinkling and creasing occur leading to high rejection rates

Engineering Contradiction:
Improveequipment simplicityVSAvoidproduct defect rate
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces a simple but effective parameter control: applying a specific tension range (0.1-5.0 N/cm) to the MDO film before lamination. This simple parameter change, combined with controlled lamination temperature (80-120°C), effectively prevents wrinkling and creasing without requiring complex equipment modifications, thus maintaining equipment simplicity while dramatically improving product reliability.

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 eliminates wrinkling and creasing issues in MDO films, enabling the production of a wide variety of laminated materials in an economically feasible process with improved stability and reduced production costs.

Implementation Method 1

a tension is exerted on the polyester film in the longitudinal direction of the film between last roll before the lamination roll and the entry side of the lamination nip prior to forming of the laminate

Methodology Applied
Scientific EffectTension: Tension

Implementation Method 2

A proper adhesion between the polymer film and the substrate is achieved by heat sealing of the polymer coating film onto the metallic substrate, wherein the film and/or the substrate may be heated to promote the heat sealing

Methodology Applied
Scientific EffectHeat sealing: Heating

Data Source

PatentEP3390057B1Process for laminating a polymeric film to a metal strip substrate
Publication Date: 2023.03.01 TATA STEEL IJMUIDEN BV
  • EP3390057B1 patent drawingFigure 1
  • EP3390057B1 patent drawingFigure 2~3
  • EP3390057B1 patent drawing

AI summary

This invention relates to a process for laminating a polyester film onto a major surface of a metal strip and to a laminated metal strip produced thereby, or a can produced therefrom.