Vulcanized Rubber Bonding via Dual Adhesive Segmentation

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Solution Overview

Problem

Existing methods for permanently connecting vulcanized rubber components in tire retreading, such as cold retreading, require a final vulcanization step that causes thermal stress and consumes energy, and cyanoacrylate adhesives are susceptible to water, leading to potential disconnection.

Innovation Solution

A method involving the application of a water-sensitive cyanoacrylate adhesive and a water-insensitive adhesive on the edges, allowing them to react at temperatures below 50°C without additional heat, eliminating the need for subsequent vulcanization and protecting against water exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If cyanoacrylate adhesive is used for bonding rubber components, then strong adhesion and flexibility are achieved, but water resistance deteriorates leading to bond failure

Engineering Contradiction:
Improveadhesion strengthVSAvoidwater resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The bonding system is segmented into two distinct adhesive layers: a first adhesive layer (water-sensitive cyanoacrylate) applied to the substrate, and a second adhesive layer (water-resistant) applied over the edges of the first layer. This segmentation allows each layer to perform its specialized function - the first provides strong adhesion while the second provides water protection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses a composite adhesive system combining two different adhesive materials with complementary properties. The cyanoacrylate adhesive provides rapid curing and flexibility, while the water-resistant adhesive provides protection against hydrolysis. Together they form a composite bonding system that achieves both strong adhesion and water resistance.

Inventive Principle:
Principle #40Composite materials

2Reliability

If final vulcanization step is applied in cold retreading, then complete curing of cushion gum is achieved, but thermal stress and energy consumption increase

Engineering Contradiction:
Improvebond completenessVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention replaces the thermal vulcanization process with a chemical adhesive bonding system. Instead of using heat and pressure to cure the cushion gum, the patent uses cyanoacrylate adhesive that cures at ambient temperature through moisture activation. This substitutes a thermal-mechanical process with a chemical process, eliminating the need for energy-intensive autoclave equipment.

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

Solution Approach 2:

The curing process parameters are changed from high temperature (vulcanization at 120-150°C) to ambient temperature (below 50°C). The adhesive is designed to cure at low temperatures through reaction with atmospheric moisture, fundamentally changing the temperature parameter of the bonding process while maintaining bond effectiveness.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If final vulcanization step is applied in cold retreading, then complete curing of cushion gum is achieved, but thermal stress on already vulcanized components increases

Engineering Contradiction:
Improvebond completenessVSAvoidthermal stress
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention replaces the thermal vulcanization process with a chemical adhesive bonding system. Instead of using heat and pressure to cure the cushion gum, the patent uses cyanoacrylate adhesive that cures at ambient temperature through moisture activation. This substitutes a thermal-mechanical process with a chemical process, eliminating the need for energy-intensive autoclave equipment.

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

Solution Approach 2:

The curing process parameters are changed from high temperature (vulcanization at 120-150°C) to ambient temperature (below 50°C). The adhesive is designed to cure at low temperatures through reaction with atmospheric moisture, fundamentally changing the temperature parameter of the bonding process while maintaining bond effectiveness.

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 method provides a durable, water-resistant connection that avoids thermal stress and energy consumption, ensuring a permanent bond even in constant water contact, reducing costs and equipment needs.

Implementation Method 1

Cyanoacrylate adhesives are commonly used as adhesives for bonding rubber components

Methodology Applied
Scientific EffectCyanoacrylate polymerization: Chemical Bonding

Implementation Method 2

applying a second, water-resistant adhesive to the outward-facing edges of the first, water-sensitive adhesive

Methodology Applied
Scientific EffectHydrophobic barrier formation: Hydrophobe

Data Source

PatentEP3539762B1Method for permanently connecting vulcanized rubber components and vehicle tyres
Publication Date: 2021.03.10 CONTINENTAL REIFEN DEUTSCHLAND GMBH
  • EP3539762B1 patent drawingFigure 1

AI summary

The invention relates to a method for permanently bonding vulcanized rubber components. The invention further relates to a vehicle tire, in particular a pneumatic tire, manufactured according to the method. The method for permanently bonding vulcanized rubber components comprises at least the following steps: - applying a first, water-sensitive adhesive (2) to at least one area of ​​the rubber components to be bonded, - applying a second, water-insensitive adhesive (3) to the outwardly facing edges of the area of ​​the first adhesive, - pressing the components to be bonded together, and - allowing the adhesives (2, 3) to cure at a temperature of less than 50 °C.