Air-Impermeable Touch Fastener Lamination via Molten Resin Cooling

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Solution Overview

Problem

Existing methods for forming composite materials struggle to create substantially air-impermeable and liquid-impermeable products while maintaining the functionality of hook-engageable surfaces, particularly when using polymers with similar melting temperatures, which often results in the destruction of loops during the bonding process.

Innovation Solution

A method involving a lamination process where a sheet-form film and a hook-engageable material are introduced into a nip between rolls, with molten resin being applied between them, allowing the resin to cool and attach to both, forming a composite material that is predominantly polypropylene, ensuring the composite is air-impermeable and retains hook-engageability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If molten resin is introduced between film and hook-engageable material to bond them, then the composite material becomes air-impermeable and liquid-impermeable, but the loops of hook-engageable material may be destroyed when using polymers with similar melting temperatures

Engineering Contradiction:
Improveair-impermeabilityVSAvoidloop integrity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the temperature of the molten resin and the speed of the lamination process. The resin temperature is maintained at a level that allows bonding without excessive heat transfer to the hook-engageable material, preserving loop integrity while achieving air-impermeability through proper resin flow and bonding pressure parameters.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements local quality by ensuring that the molten resin is applied locally between the film and hook-engageable material only where bonding is required. This localized application prevents overheating and destruction of loops in areas where bonding is not needed, while still achieving the necessary air-impermeable seal in the bonded regions.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If polymer materials with similar melting temperatures are used for film, resin, and hook-engageable material, then recyclability is improved, but the loops are more susceptible to destruction during bonding

Engineering Contradiction:
ImproverecyclabilityVSAvoidloop integrity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent resolves this contradiction by changing process parameters rather than material composition. By controlling resin temperature, lamination speed, and pressure, the process enables bonding of polypropylene-based materials (which are recyclable) without destroying the loops, thus maintaining both recyclability and loop integrity through parameter optimization.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The molten resin acts as an intermediary that bonds the film to the hook-engageable material without requiring the materials themselves to have different melting temperatures. The resin mediates the bonding process, allowing recyclable materials to be joined while protecting the loops from direct thermal damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If conventional lamination methods are used to create air-impermeable composites, then liquid-impermeability is achieved, but the hook-engageable surface functionality is compromised

Engineering Contradiction:
Improveliquid-impermeabilityVSAvoidhook-engageability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies local quality by restricting the molten resin application to specific regions between the film and hook-engageable material. This ensures that liquid-impermeability is achieved in the bonded areas while leaving the hook-engageable surface areas unaffected and fully functional for their intended purpose.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses partial action by applying molten resin only where necessary for bonding and impermeability, rather than coating the entire surface. This partial application maintains the air and liquid impermeability needed for medical applications while preserving the hook-engageable functionality in non-bonded regions.

Inventive Principle:
Principle #16Partial or excessive 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 method efficiently produces air-impermeable and liquid-impermeable composite materials with hook-engageable surfaces, facilitating the formation of products like medical compression devices and bladders, while maintaining the recyclability and weldability of polypropylene components, and reducing noise during inflation due to embossed regions.

Implementation Method 1

introducing molten resin into the nip between the film and the hook-engageable material, and allowing the molten resin to cool so that the film becomes attached to the hook-engageable material by the cooled resin

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 2

allowing the molten resin to cool so that the film becomes attached to the hook-engageable material by the cooled resin

Methodology Applied
Scientific EffectSolidification: Freezing

Implementation Method 3

introducing a sheet-form film and a hook-engageable material into a nip formed between a first roll and a second roll

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2558296B1Method of forming laminates for touch fasteners
Publication Date: 2014.07.02 VELCRO IND BV
  • EP2558296B1 patent drawingFigure 1
  • EP2558296B1 patent drawingFigure 2~3
  • EP2558296B1 patent drawingFigure 4~6

AI summary

A method of forming a substantially air-impermeable composite material includes introducing a sheet-form film and a loop material into a nip formed between a first roll and a second roll, introducing molten resin into the nip between the film and the loop material, and allowing the molten resin to cool so that the film becomes attached to the loop material by the cooled resin.