Two-Component Epoxy Adhesive

Two-Component Epoxy Adhesive: Applications and Characteristics

Two-component epoxy adhesives are essential in modern manufacturing and construction, offering versatile, strong, and durable bonds for various materials. In this blog, we’ll explore their characteristics, applications, and advantages, providing an easy-to-understand overview for everyone. For more on epoxy adhesives, see our previous blogs.

Understanding Two-Component Epoxy Adhesives

What are Two-Component Epoxy Adhesives?

Two-component epoxy adhesives, also known as two-part epoxies or reactive adhesives, are a type of structural adhesive that cures through a chemical reaction between two separate components: a resin and a hardener (or curing agent). Unlike adhesives that dry or cure through the evaporation of solvents or water, two-component epoxies rely on a chemical reaction that occurs when the resin and hardener are mixed. This reaction creates a strong, durable bond capable of withstanding significant mechanical stresses and environmental conditions.

How Do They Work?

The working mechanism of two-component epoxy adhesives can be broken down into a few key steps:

  1. Preparation: The two components—resin and hardener—are stored separately until they are ready to be used. It prevents premature curing and ensures a longer shelf life for the adhesive.
  2. Mixing: When it’s time to use the adhesive, the resin and hardener are mixed in a specific ratio. This ratio must be precise, as the strength and effectiveness of the bond depend on the correct proportions of each component.
  3. Application: Once mixed, the adhesive is applied to the surfaces that need to be bonded. The mixture begins to react and cure almost immediately, so it’s important to work quickly and efficiently.
  4. Curing: The chemical reaction between resin and hardener generates heat (exothermic), causing the mixture to harden and form a strong bond. It can occur at room temperature, but applying heat can speed up the process and improve adhesive properties.

Characteristics of Two-Component Epoxy Adhesives

Two-component epoxy adhesives are known for their impressive range of characteristics, which make them suitable for various applications:

  1. High Strength: These adhesives create incredibly strong bonds that can hold up under significant mechanical stress, making them ideal for structural applications.
  2. Durability: They are highly resistant to environmental factors such as moisture, temperature fluctuations, and chemicals, ensuring long-lasting performance.
  3. Versatility: Epoxy adhesives can be formulated to meet specific requirements, including different curing times, viscosities, and mechanical properties.
  4. Customization: The addition of fillers and additives can modify the properties of the adhesive, making it suitable for a wide range of applications, from flexible to rigid bonds.
  5. Chemical Resistance: Epoxy adhesives are resistant to many chemicals, including acids, alkalis, solvents, and fuels, making them suitable for use in harsh environments.
  6. Thermal Stability: They can withstand a wide range of temperatures, from extreme cold to high heat, without losing their bonding strength.

Applications of Two-Component Epoxy Adhesives

Two-component epoxy adhesives are used in a vast array of industries due to their strength and versatility. For a deeper understanding of epoxy adhesives in general, refer to our previous blog on “Understanding Epoxy Adhesives. Here are some of the most common applications:


In the aerospace industry, the reliability and strength of adhesive bonds are paramount. Two-component epoxies are used to bond structural components, composites, and various materials in aircraft. Their resistance to extreme temperatures and environmental conditions makes them ideal for this high-stakes field.

Automotive and Transport

The automotive industry relies on two-component epoxy adhesives to assemble vehicles, including cars, trucks, and railway vehicles. These adhesives bond metals, composites, and other materials, providing strong, durable joints that can withstand the stresses of everyday use and harsh environments.


These adhesives bond materials such as concrete, metal, glass, and wood. They are particularly useful in prefabricated construction elements, doors, gates, and structural components where high-strength bonds are required.


Two-component epoxy adhesives are widely used in the electronics industry for potting, encapsulating, and bonding electronic components. Their excellent electrical insulation properties and resistance to environmental factors make them ideal for protecting sensitive electronics.

Medical Devices

The medical field demands adhesives that are not only strong and durable but also safe for use in medical environments. Two-component epoxies are used to assemble and bond medical devices, ensuring they can withstand repeated use and sterilization processes.


In marine applications, the adhesive’s resistance to water and chemicals is crucial. Two-component epoxies are used to bond and seal various components in boats and ships, ensuring long-lasting performance even in harsh marine environments.

Household Appliances

From washing machines to refrigerators, household appliances require strong, durable bonds to function correctly. Two-component epoxy adhesives are used to assemble and bond various components, ensuring the appliances can withstand daily wear and tear.

Choose from ThreeBond’s Best Two-Component Epoxy Adhesives

ThreeBond 2045B and 2145B

ThreeBond 2045B and 2145B are two-component epoxy resins designed to provide high thermal conductivity and strong adhesive properties at room temperature. These resins are ideal for applications requiring efficient heat dissipation and robust bonding, particularly in battery technology. Here’s a detailed look at their features, technology, and examples of their applications.

Features / Technology
  • Room Temperature Curing: Cures at 25°C in 24 hours, no heating needed.
  • High Adhesive Strength: Strong bond to steel, aluminum, copper, and nickel plating.
  • Thermal Conductivity: 2.1 W/m・K for efficient heat dissipation.
  • Safety Compliance: Equivalent to UL94 V-0 flame retardancy.
  • Durability: Excellent heat and humidity resistance.
Examples of Use
  • Battery Heat Dissipation: Manages heat in battery cells.
  • Bonding and Encapsulation:
    • Electronics: Bonds and encapsulates heat-generating components.
    • Automotive: Suitable for parts needing strong bonds and heat management.
  • Industrial Metal Bonding: Effective for joining various metals with heat dissipation needs.

ThreeBond 2086M

Features / Technology

TB2086M is a two-component epoxy resin and hardener system designed for fast fixturing and bonding of various materials. Key features include:

  • Rapid Setting: Achieves handleable bonds in 5 minutes and full properties in 30 minutes at room temperature.
  • Mix Ratio: Simple 1:1 mix ratio, packaged in a convenient 50ml twin cartridge.
  • Low Viscosity: Ensures excellent flowability and workability.
  • Transparency: Mixed resin is transparent and ideal for cosmetically sensitive parts.
  • High Performance: Offers excellent electrical properties, mechanical strength, and chemical resistance.
  • Wide Range of Bonding: Bonds metals, engineered plastics, ceramics, stone, wood, FRP, and rubbers.
  • Low Temperature Curing: Capable of setting at low temperatures (5ºC).
Examples of Use
  • Electronics Bonding/Sealing: Ideal for bonding and sealing electronic components.
  • Potting/Encapsulation: Suitable for potting and encapsulating sensitive electronics.
  • Structural Bonding: Effective for structural bonding applications requiring strong and durable bonds.

ThreeBond 2088E

Features / Technology

ThreeBond 2088E is a cold-curing, two-part epoxy resin designed for high adhesion under heat. Key features include:

  • High Adhesion: Exhibits strong adhesion, achieving over 50 kg/cm² at 25°C for 7 days and over 100 kg/cm² at 120°C for 1 hour at a measuring temperature of 200°C.
  • Long Pot Life: Offers an extended working time before curing, allowing for flexibility during application.
  • Heat Resistance: Excellent heat resistance, making it suitable for high-temperature environments.
  • High Tg (Glass Transition Temperature): Ensures the material remains stable and strong at elevated temperatures.
  • High Strength: Provides robust mechanical strength, essential for demanding applications.
  • Two-Component Mixture Curing: This process comprises a main agent (epoxy resin) and a curing agent (polyamide amine), both of which are clear yellow to yellow-brown in appearance.
  • Viscosity: The main agent has a viscosity of 40 Pa・s, while the curing agent has a viscosity of 4 Pa・s.
Examples of Use
  • Automotive Market: Used in vehicle powertrains, electrical components, construction machines, and marine vessels.
  • Public Industrial Material Market: Applied in infrastructure, construction, and general machinery.
Specific Applications:
  • Temporary Securing: Parts that need to be temporarily secured before being bonded with one-part heat-curing epoxy resins.
  • Heated Piping Joints: Effective for bonding joints in heated piping systems.
  • Bonding and Repair: Suitable for fire protection equipment parts, metals, and ceramics, providing strong and durable bonds and repairs.

Working with Two-Component Epoxy Adhesives

Using two-component epoxy adhesives requires careful preparation and attention to detail. Here are some essential steps to ensure successful bonding:


Proper mixing is critical for achieving the desired bond strength and curing properties. The resin and hardener must be mixed in the correct ratio, which can vary depending on the specific adhesive formulation. Common ratios include 1:1, 2:1, or 10:1 parts by volume.


Once mixed, the adhesive should be applied immediately to the surfaces that need to be bonded. The mixture will begin to cure quickly, so it’s essential to work efficiently. Applying the adhesive in a uniform layer ensures a strong, even bond.


Curing times can vary depending on the adhesive formulation and environmental conditions. While many two-component epoxies cure at room temperature, applying heat can accelerate the process and enhance the adhesive’s properties. Follow the manufacturer’s guidelines for curing times and conditions.

Safety Precautions

Working with two-component epoxy adhesives requires proper safety measures. Always wear protective gloves, goggles, and clothing to prevent skin and eye contact with the adhesive components. Ensure adequate ventilation in the workspace to avoid inhaling fumes.

Advantages of Two-Component Epoxy Adhesives

Two-component epoxy adhesives offer several advantages over other types of adhesives:

Defined Curing Time

The curing time for two-component epoxies is predictable, allowing for precise planning and scheduling in manufacturing and construction processes.


    These adhesives are typically solvent-free, making them environmentally friendly and safer to use in various applications.

    High-Strength Joints

    The bonds created by two-component epoxies are incredibly strong, often stronger than the materials being bonded. It makes them ideal for structural applications where reliability is crucial.

    Resistance to Environmental Factors

    Two-component epoxies are highly resistant to chemicals, moisture, temperature fluctuations, and UV radiation, ensuring long-lasting performance even in harsh environments.


    The ability to customize two-component epoxy formulations allows for a wide range of applications, from flexible to rigid bonds and from small electronic components to large structural elements.


    Two-component epoxy adhesives are a versatile, reliable, and high-performance solution for a wide range of applications across various industries. Their strength, durability, and resistance to environmental factors make them the preferred choice for many demanding bonding tasks. Whether you’re working in aerospace, automotive, construction, electronics, or any other field that requires strong, durable bonds, two-component epoxy adhesives offer the performance and reliability you need.

    By understanding the characteristics, applications, and advantages of these adhesives, you can make informed decisions about their use in your projects, ensuring successful and long-lasting bonds every time.

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