Curable Adhesive Tape Jacketing for Low-Temperature Cable Harness Bonding

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Solution Overview

Problem

Current methods for wrapping cable harnesses using adhesive tapes face challenges such as high curing temperatures that can damage PVC insulation, leading to increased manufacturing costs and the need for prefabricated cable plans, which are not practical for automotive manufacturing processes.

Innovation Solution

A method utilizing a thermally curable adhesive tape with an epoxy-functionalized acrylonitrile/butadiene copolymer and a ground reaction product of phthalic anhydride and diethylenetriamine, which cures at temperatures between 60°C and 110°C, providing chemical crosslinking and maintaining adhesive properties without being meltable after curing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high curing temperature (175°C) is used to cure the adhesive, then the adhesive achieves proper curing and bonding strength, but the PVC cable insulation is damaged

Engineering Contradiction:
Improveadhesive curingVSAvoidinsulation damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the curing temperature parameter from conventional high temperatures (175°C) to low temperatures (60-110°C). This is achieved by modifying the adhesive chemistry to use a two-component system with isocyanate and hydroxyl groups that cure at lower temperatures, thereby protecting the PVC insulation while still achieving proper adhesive curing and bonding strength.

Inventive Principle:
Principle #35Parameter changes

2Shape

If prefabricated injection-molded parts are used to maintain cable shape, then the cable harness maintains its shape without contacting the engine, but additional material and assembly costs are incurred

Engineering Contradiction:
Improvecable harness shapeVSAvoidmanufacturing cost
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent merges the adhesive tape function with the cable shape-maintaining function. The low-temperature curable adhesive tape not only bonds the cables together but also maintains the cable harness shape and positioning, eliminating the need for separate injection-molded parts and reducing material and assembly costs.

Inventive Principle:
Principle #5Merging (Combining)

3Temperature

If the adhesive cures at low temperature (60-110°C), then the PVC insulation is protected and manufacturing costs are reduced, but the adhesive must not cure during storage

Engineering Contradiction:
Improvecuring temperatureVSAvoidadhesive stability
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The patent segments the adhesive into two separate components: a base adhesive containing isocyanate groups and a curing agent containing hydroxyl groups. During storage, the components remain separate and stable. When applied, they mix and initiate the curing reaction at low temperatures, achieving both storage stability and low-temperature curing.

Inventive Principle:
Principle #1Segmentation

4Productivity

If the adhesive cures within 6 minutes to meet process specifications, then the manufacturing efficiency is improved, but the adhesive formulation becomes more complex

Engineering Contradiction:
Improvecuring speedVSAvoidadhesive formulation
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent incorporates preliminary action by pre-formulating the adhesive with a catalyst and optimizing the molecular structure of the polyol and isocyanate components. This preliminary preparation enables the curing reaction to proceed rapidly at low temperatures, achieving full cure within 6 minutes without excessive formulation complexity.

Inventive Principle:
Principle #10Preliminary 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 solution allows for efficient integration of the adhesive tape into manufacturing processes, achieving high tensile shear strengths and excellent storage stability, enabling the production of robust and durable cable harnesses with reduced material and assembly costs.

Implementation Method 1

the curable adhesive is cured by the supply of thermal energy at a temperature between 60 °C and 110 °C

Methodology Applied
Scientific EffectThermal energy supply: Heating

Implementation Method 2

The curing thus achieved involves chemical crosslinking, so that the adhesive is no longer meltable after curing

Methodology Applied
Scientific EffectChemical crosslinking: Chemical Bonding

Data Source

PatentEP4004951B1Method for jacketing elongate articles, in particular lines
Publication Date: 2024.02.14 TESA SE
  • EP4004951B1 patent drawingFigure 1
  • EP4004951B1 patent drawingFigure 2
  • EP4004951B1 patent drawing

AI summary

The invention relates to a method for jacketing elongate articles, such as lines or cable harnesses in particular, by means of an adhesive tape comprising a tape-shaped substrate, which substrate has, on at least one side, a thermally curable, meltable, preferably pressure-sensitive adhesive layer, the adhesive layer comprising an epoxide-functionalized acrylonitrile-butadiene copolymer which has on average more than 1.5 epoxide groups per molecule and comprising the reaction product of phthalic anhydride and diethylenetriamine, the adhesive tape being led in a helix around the elongate article or the elongate article being enveloped by the adhesive tape in the axial direction, the elongate article together with the enveloping adhesive tape being brought into the desired arrangement, in particular into the cable harness plan, the elongate article being held in this arrangement, and the curable adhesive mass being cured by supplying thermal energy, in particular at a temperature of up to 110 °C.