Nonwoven Electrical Insulation Material Thermal Bonding

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electrical insulation materials for transformers, motors, and generators often require adhesives or thermoplastic films for bonding, which add cost and risk of brittleness under high temperatures, and lack a balanced combination of mechanical reinforcement and dielectric insulation properties.

Innovation Solution

A nonwoven paper layer fused with a nonwoven fabric layer without adhesives or thermoplastic films, using short fibers with inorganic fillers and long fibers, providing a synergistic balance of mechanical and dielectric strengths through thermal bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If adhesives are used for bonding nonwoven layers, then bonding strength is improved, but brittleness increases under high temperatures

Engineering Contradiction:
Improvebonding strengthVSAvoidresistance to brittleness at high temperature
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent removes adhesives from the bonding process entirely, extracting the harmful element that causes brittleness at high temperatures. The nonwoven layers are bonded through thermal bonding of the fibers themselves, eliminating the adhesive layer that would otherwise degrade and become brittle under thermal stress.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the chemical bonding mechanism (adhesives) with a thermal-mechanical bonding mechanism (thermal bonding of fibers). The fibers are directly bonded through heat and pressure, substituting the adhesive chemical system with a physical thermal-mechanical system that maintains reliability at high temperatures.

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

2Strength

If thermoplastic films are used for bonding, then bonding strength is improved, but cost and processing complexity increase

Engineering Contradiction:
Improvebonding strengthVSAvoidprocessing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent extracts thermoplastic films from the bonding structure, eliminating the need for separate film layers. The bonding function is achieved directly through the nonwoven fabric layers themselves via thermal bonding, removing unnecessary components and simplifying the overall structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The nonwoven fabric layers serve multiple functions simultaneously: they provide structural support, enable bonding through thermal bonding of fibers, and eliminate the need for separate adhesives or thermoplastic films. This multi-functionality reduces processing complexity and device structure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If inorganic fillers are added to nonwoven paper, then dielectric strength is improved, but mechanical strength may deteriorate

Engineering Contradiction:
Improvedielectric strengthVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent creates a composite structure by combining nonwoven paper with inorganic fillers (for dielectric properties) and reinforcing it with nonwoven fabric layers (for mechanical strength). The fabric layer acts as a reinforcement that compensates for any mechanical strength loss from the fillers, while the paper layer provides the dielectric function.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies different material compositions to different layers: the nonwoven paper layer contains inorganic fillers optimized for dielectric strength, while the nonwoven fabric layer is composed of fibers optimized for mechanical reinforcement. Each layer has localized properties tailored to its specific function, and together they achieve both dielectric and mechanical requirements.

Inventive Principle:
Principle #3Local quality

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 improved mechanical strength, resistance to high temperatures, and excellent dielectric breakdown strength without the need for additional adhesives or thermoplastic films, maintaining flexibility after heat aging.

Implementation Method 1

thermal bonding and densification of the component materials result in an electrical insulating material having a desirable balance of properties

Methodology Applied
Scientific EffectThermal bonding: Heating

Data Source

PatentEP2651633B1Electrical insulation material
Publication Date: 2017.11.01 3M INNOVATIVE PROPERTIES CO

AI summary

Provided in at least one embodiment is a nonwoven paper layer directly fused on one or both sides with a nonwoven fabric layer wherein one or both of the nonwoven paper and nonwoven fabric are electrically insulating.