Thermally fusible sheet body

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Solution Overview

Problem

Current adhesive systems for interlining materials in the textile industry face challenges such as contamination during application, inhomogeneous bonding, and limited resistance to chemical cleaning and garment dyeing processes, especially with light and open carrier layers.

Innovation Solution

A thermally fixable fabric with a carrier layer coated using a polyurethane mixture comprising polyesterurethane, polyetherurethane, and polycarbonate urethane, crosslinked with a blocked isocyanate, which provides excellent post-processing properties, low riveting back, and resistance to chemical cleaning and high-temperature drying.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional adhesive systems are used on light and open carrier layers, then application is simpler, but contamination during application occurs and bonding becomes inhomogeneous

Engineering Contradiction:
Improveapplication simplicityVSAvoidbonding homogeneity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the physical and chemical parameters of the adhesive system by using a polyurethane mixture with specific viscosity characteristics and blocked isocyanate crosslinking agents. This allows the adhesive to maintain stability during application on light carrier layers while achieving homogeneous bonding through controlled crosslinking at elevated temperatures, resolving the contradiction between application simplicity and bonding homogeneity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite adhesive system consisting of multiple polyurethane components (polyesterurethane, polyetherurethane, and polycarbonate urethane) combined with blocked isocyanate crosslinkers. This composite formulation provides both the ease of application required for light carrier layers and the homogeneous bonding performance needed, as each component contributes specific properties to the overall adhesive system.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional adhesive systems are used, then processing is easier, but resistance to chemical cleaning and garment dyeing is limited

Engineering Contradiction:
Improveprocessing easeVSAvoidresistance to chemical cleaning and garment dyeing
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent fundamentally changes the chemical parameters of the adhesive system by implementing a crosslinking mechanism using blocked isocyanates. This creates a three-dimensional network structure that significantly enhances resistance to chemical cleaning and garment dyeing processes while maintaining processing ease through controlled crosslinking at standard finishing temperatures, thus resolving the contradiction between processing ease and chemical resistance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional physical bonding mechanisms with chemical crosslinking bonds. The blocked isocyanate groups form covalent bonds with the polyurethane chains, creating a chemically crosslinked network that provides superior resistance to chemical cleaning and garment dyeing compared to conventional thermoplastic adhesives that rely on physical entanglement and melting.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If crosslinking is achieved with unblocked isocyanate, then bonding strength increases, but application becomes difficult due to premature reaction

Engineering Contradiction:
Improvebonding strengthVSAvoidapplication difficulty
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by using blocked isocyanates that prevent premature crosslinking during adhesive application and bonding operations. The blocking agents temporarily mask the isocyanate groups, allowing the adhesive to be applied and positioned without premature reaction. Subsequently, during a curing or finishing step at elevated temperatures, the blocking agents are removed or decomposed, enabling the isocyanates to crosslink and achieve high bonding strength, thus resolving the contradiction between bonding strength and application ease.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces blocking agents as intermediaries that temporarily deactivate the isocyanate groups during application. These blocking agents (such as water, alcohols, or amines) form reversible adducts with the isocyanates, preventing premature crosslinking. During subsequent heating or curing, the blocking agents are eliminated or decomposed, releasing the isocyanates to form the final crosslinked network with high bonding strength, thereby mediating between application requirements and final bonding performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution achieves excellent wash resistance, elasticity, and tactile performance, allowing for the production of soft, elastic, and durable interlining materials suitable for garment dyeing and other demanding textile applications without compromising the quality of production systems.

Implementation Method 1

crosslinked with a blocked isocyanate

Methodology Applied
Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 2

thermally fixable fabric

Methodology Applied
Scientific EffectThermal crosslinking: Heat Treatment

Implementation Method 3

resistance to chemical cleaning and high-temperature drying

Methodology Applied
Scientific EffectThermal resistance: Thermal Insulation

Implementation Method 4

The fiber web usually consists of polyester or polyamide fibers specially developed for this process

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3701081B1Thermally fusible sheet body
Publication Date: 2023.12.06 CARL FREUDENBERG KG
  • EP3701081B1 patent drawingFigure 1
  • EP3701081B1 patent drawingFigure 2

AI summary

The invention relates to a thermally fusible sheet body usable in particular as a fusible interlining in the textile industry which comprises a support layer made of a textile material on top of which has been applied an adhesive composition structure comprising a polyurethane coating containing a polyurethane mixture comprising at least one polyester urethane (B1), at least one polyether urethane (B2) and at least one polycarbonate urethane (B3) and wherein the polyurethane mixture has been at least partially crosslinked with a crosslinker comprising at least one isocyanate blocked with a blocking agent at at least one isocyanate group.