Reversible hybrid metal-composite connections for sustainable assemblies

AI Quick Summary

This work aims to investigate different reversible techniques to join thermoset composite-composite and composite-metal substrates and to detach and recycle them separately at the end of their lifespan, promoting innovative and circular solutions. Thematic focus Reliable and cost-effective joining technologies for fibre-reinforced composite materials provide a great potential to significantly reduce weight, fuel consumption, and, consequently, CO2 emissions. Joining techniques, which allow easy dismantling at the end-of-life, permit the repair, re-use and re-design of the same composite parts or efficient recycling of the separated components, further improving the CO2 footprint of the energy-intensively manufactured components. Therefore, this work investigates different reversible techniques for joining thermoset composite parts to other thermoset composite or metal substrates and detaching, reusing, or recycling them separately at the end of their lifespan. The work will explore: Thermoset composite-metal joints (OST): The debonding of epoxy adhesives using electromagnetic induction. Non-reactive high-strength hotmelt adhesives. Elastically deforming connectors inspired by the press-fit technology. Ultrasonic rivet welding using thermoplastic pins. Thermoset composite-composite/ composite-metal joints (FHNW): Ultrasonic welding, dismantling and rewelding of epoxy-based composites via a co-cured thermoplastic coupling layer. Degree of innovation The novelty of the approach is to explore structural joining techniques for thermoset composites that can be easily detached at the end-of-life by implementing a design for recycling. The debonding of epoxy adhesives with embedded iron particles has not been investigated thoroughly or brought to an application so far but offers a high potential for efficient structural bonding and debonding. Additionally, the fast thermoplastic joining of thermosets is entirely new to the field of composites and is, therefore, highly innovative. FHNW and OST initiated the project ideas based on the challenge presented by Connova. Thanks to the platform provided by the Innovation Booster the collaborative consortium was formed, working together towards the same goal. Connova will extend the team as an implementation partner. Effect Connova gains the knowledge and tools to offer their customers individual thermoset composite solutions which can be recycled more efficiently through easy disassembling, which provides a competitive advantage and the opportunity to acquire new customers and sales fields. If thermoplastics, with their ability to be welded, are used for bonding, additional advantages are reduced manufacturing cost and time. The increased lifespan through component repair and reuse, and more efficient recycling, reduce the number of petrochemical resources and energy input for manufacturing and thus CO2 emissions. Methodological quality The FHNW and the OST, with their deep knowledge of the proposed solutions and laboratory infrastructures, are ideal research partners to realize the needs of the industry through a design thinking approach. Connova will ensure the implementation of the research results. Gender and Diversity Connova is driving towards a sustainable material future, to which a diverse and productive team structure is vital. With their policies of diversity and equality of opportunities, Connova, FHNW and OST respect and support all genders. Therefore, a mixed project team will be set up including different genders. Scope and Tasks The project's scope will be to evaluate different joining technologies regarding their potential for innovative reversible composite-composite or composite-metal connections. The work will be based on specifications for the joint, which Connova will provide prior to the project's start. Work packages: WP1: Thermoset composite-metal joints (OST): Debonding of epoxy adhesives using electromagnetic induction. Identification of suitable products, joining, tests and evaluation of lap-shear specimens Separation process of the joint Reversible bonding with non-reactive high-strength hotmelt adhesives. Identification of suitable products, bonding and tests of lap-shear specimens Separation process of the joint Detachable elastically deforming connectors inspired by the press-fit technology. Proposal of concepts using CAD Detachable ultrasonic rivet welding using thermoplastic pins. Proposal of concepts using CAD WP 2: Thermoset composite-composite joints (FHNW):Ultrasonic welding, dismantling and rewelding of epoxy-based composites via a co-cured thermoplastic coupling layer. Selection and characterization of materials focusing on reaction-diffusion properties between epoxy and thermoplastic. Manufacture of composite plates with optimal coupling layer, optimization of welding process for lab specimens and feasibility study on dismantling and reuse capabilities Welding, separation and rewelding study performed in a Design of Experiment WP3: Reviewing of results for different joining techniques (Connova, OST, FHNW): Evaluation of results regarding quality of the bonding, possibility of de-assembly and suitability for different usage conditions Formulation of first design principles In order to reach the goals of this project, WP1 and WP2 need to be completed. These two will prove the potential of the joining anddisassembly concepts proposed so far and their compatibility with the specifications of Connova. Budget We would ask for the support of CHF 25’000 seed money, which will be used by FH OST and FHNW (for WP1/2/3). The budget will be shared as follows: OST: 15 kCHF, FHNW: 10 kCHF. We plan to get support for the mandatory assessment of the CO2 reduction potential for a lump sum of CHF 1’000. Co-Funding Connova acts as implementation partner.

Project Idea Metadata

• Project Idea Name: Reversible hybrid metal-composite connections for sustainable assemblies
• Date: 11/14/2022 9:49:53 AM
• Administrators:

Project Idea Description

Thematic focus

Reliable and cost-effective joining technologies for fibre-reinforced composite materials provide a great potential to significantly reduce weight, fuel consumption, and, consequently, CO2 emissions. Joining techniques, which allow easy dismantling at the end-of-life, permit the repair, re-use and re-design of the same composite parts or efficient recycling of the separated components, further improving the CO2 footprint of the energy-intensively manufactured components.

Therefore, this work investigates different reversible techniques for joining thermoset composite parts to other thermoset composite or metal substrates and detaching, reusing, or recycling them separately at the end of their lifespan.

The work will explore:

Thermoset composite-metal joints (OST):

• The debonding of epoxy adhesives using electromagnetic induction.
• Non-reactive high-strength hotmelt adhesives.
• Elastically deforming connectors inspired by the press-fit technology.
• Ultrasonic rivet welding using thermoplastic pins.

Thermoset composite-composite/ composite-metal joints (FHNW):

• Ultrasonic welding, dismantling and rewelding of epoxy-based composites via a co-cured thermoplastic coupling layer.

Degree of innovation

The novelty of the approach is to explore structural joining techniques for thermoset composites that can be easily detached at the end-of-life by implementing a design for recycling. The debonding of epoxy adhesives with embedded iron particles has not been investigated thoroughly or brought to an application so far but offers a high potential for efficient structural bonding and debonding. Additionally, the fast thermoplastic joining of thermosets is entirely new to the field of composites and is, therefore, highly innovative.

FHNW and OST initiated the project ideas based on the challenge presented by Connova. Thanks to the platform provided by the Innovation Booster the collaborative consortium was formed, working together towards the same goal. Connova will extend the team as an implementation partner.

Effect

Connova gains the knowledge and tools to offer their customers individual thermoset composite solutions which can be recycled more efficiently through easy disassembling, which provides a competitive advantage and the opportunity to acquire new customers and sales fields. If thermoplastics, with their ability to be welded, are used for bonding, additional advantages are reduced manufacturing cost and time.

The increased lifespan through component repair and reuse, and more efficient recycling, reduce the number of petrochemical resources and energy input for manufacturing and thus CO2 emissions.

Methodological quality

The FHNW and the OST, with their deep knowledge of the proposed solutions and laboratory infrastructures, are ideal research partners to realize the needs of the industry through a design thinking approach. Connova will ensure the implementation of the research results.

Gender and Diversity

Connova is driving towards a sustainable material future, to which a diverse and productive team structure is vital. With their policies of diversity and equality of opportunities, Connova, FHNW and OST respect and support all genders. Therefore, a mixed project team will be set up including different genders.

Scope and Tasks

The project's scope will be to evaluate different joining technologies regarding their potential for innovative reversible composite-composite or composite-metal connections. The work will be based on specifications for the joint, which Connova will provide prior to the project's start.

Work packages:

WP1: Thermoset composite-metal joints (OST):

1. Debonding of epoxy adhesives using electromagnetic induction.
2. Identification of suitable products, joining, tests and evaluation of lap-shear specimens
3. Separation process of the joint
4. Reversible bonding with non-reactive high-strength hotmelt adhesives.
5. Identification of suitable products, bonding and tests of lap-shear specimens
6. Separation process of the joint
7. Detachable elastically deforming connectors inspired by the press-fit technology.
8. Proposal of concepts using CAD
9. Detachable ultrasonic rivet welding using thermoplastic pins.
10. Proposal of concepts using CAD

WP 2: Thermoset composite-composite joints (FHNW):

Ultrasonic welding, dismantling and rewelding of epoxy-based composites via a co-cured thermoplastic coupling layer.

1. Selection and characterization of materials focusing on reaction-diffusion properties between epoxy and thermoplastic.
2. Manufacture of composite plates with optimal coupling layer, optimization of welding process for lab specimens and feasibility study on dismantling and reuse capabilities
3. Welding, separation and rewelding study performed in a Design of Experiment

WP3: Reviewing of results for different joining techniques (Connova, OST, FHNW):

1. Evaluation of results regarding quality of the bonding, possibility of de-assembly and suitability for different usage conditions
2. Formulation of first design principles

In order to reach the goals of this project, WP1 and WP2 need to be completed. These two will prove the potential of the joining and

disassembly concepts proposed so far and their compatibility with the specifications of Connova.

Budget

We would ask for the support of CHF 25’000 seed money, which will be used by FH OST and FHNW (for WP1/2/3). The budget will be shared as follows:

OST: 15 kCHF,

FHNW: 10 kCHF.

We plan to get support for the mandatory assessment of the CO2 reduction potential for a lump sum of CHF 1’000.

Co-Funding

Connova acts as implementation partner.

This work aims to investigate different reversible techniques to join thermoset composite-composite and composite-metal substrates and to detach and recycle them separately at the end of their lifespan, promoting innovative and circular solutions.