The main objective of the research part of the project is to develop a hybrid technology that enables the production of high-performance composite structures with a recyclable thermoplastic matrix. The proposed hybrid technology combines the advantages of three of the most promising processing techniques—thermoplastic resin transfer moulding (T-RTM) and/or injection moulding, and additive manufacturing, within the production of a single part.
Leader of research: Assoc. Prof. Dr. Irena Pulko
The research part of the project is divided into five tasks:
- Study of the interfacial bonding strength (Task 1.1)
- Synthesis of covalent adaptable networks (CAN) using reactive extrusion and compounding (Task 1.2)
- Study of improvement of interfacial bonding strength between different polymers (Task 1.3)
- Use of CAN in hybrid technologies (Task 1.4)
- Development of demonstrators (Task 1.5)
Study of the interfacial bonding strength (Task 1.1)
In this task, we investigated the bonding strength between components made from different materials. Specifically, we examined components produced using two distinct technologies: T-RTM/IM and AM. Our goal was to understand how these technologies and materials affect the interfacial bonding strength. Therefore we focused on the preparation of injection molded polyamide plates on which we printed a ribbed structure (PA, TPU) applying various additive technologies. We studied the influence of the contact area, surface roughness and process parameters on the strength of the bond between the two components. Additionally, we investigated the effect of silanization of the surface on the adhesion of the components.
In order to predict the strength of the bond between the individual components, the partners from BME developed a mathematical model for ABS, PC and PS that correlates 90% with the measured values.
Published research findings:
Synthesis of covalent adaptable networks (CAN) using reactive extrusion and compounding (Task 1.2)
We prepared polypropylene and acrylonitrile butadiene styrene - based polymers with flexible covalent bonds using appropriate catalysts and crosslinkers.
In the initial phase, the experiments were carried out in small quantities and the selected polymers were then prepared by reaction extrusion at FTPO. From the granulates prepared in this way, test specimens were prepared by injection moulding, and their thermal and mechanical properties were characterized by DSC, TGA, TMA and DMA. With the polymers that prove to be the most suitable, we will prepare composites to be used in 3D printing in Task 1.3. The goal of this part is to prepare materials enabling triggered bonding and debonding and therefore easy recycling of composite parts.
Study of improvement of interfacial bonding strength between different polymers (Task 1.3)
Materials prepared in Task 1.2 will be injection overmoulded onto substrates. Adhesive and self-healing properties of prepared samples will be evaluated by autogenous welding of substrates, various post-processing procedures (such as annealing,…) and subsequent characterization of mechanical and thermomechanical properties. Best performing materials will be selected for the preparation of materials in suitable forms for various AM processes.
Use of CAN in hybrid technologies (Task 1.4)
All four beneficiaries and one associated partner possess various AM printers, which need materials prepared in a specific form such as filaments, granules or powders. The same prepared materials will be distributed among partners to be used for overprinting on substrates prepared by IM or T-RTM. Bonding strengths will be determined according to standards and compared to results from Task 1.1. Best strategies for high bonding strength between the components will be evaluated. Besides, filaments will be used for the round-robin test of FFF, since all four beneficiaries and one associated partner possess FFF printers of various producers. The processing conditions will be as similar as possible. Comparing the results of mechanical and other properties from all four beneficiaries and one associated partner will give valuable info about the repeatability of data.
Development of demonstrators (Task 1.5)
A demonstrator will be chosen in the first period of the project.