Fraunhofer Institute for Industrial Mathematics ITWMIn the »3-ScaleSim« project, researchers from the Fraunhofer Institute for Microstructure of Materials and Systems IMWS and a team from our »Grid-Free Methods« department are developing a simulation tool for multiscale injection molding of plastics. The basis for this is our MESHFREE simulation software developed at Fraunhofer ITWM, which we are expanding in the project to map micro- and nanostructures. The goal is to accurately predict micro- and nanostructures on plastic surfaces and significantly accelerate industrial development processes. The project contributes to developing innovative plastic products faster, more cost-effectively, and more sustainably.
Smartphone: Micro- and nanostructuring can improve the bonding of plastic components while reducing diffuse reflections on display surfaces.
Hearing aid: Micro- and nanostructuring of earmolds to optimize adhesion properties and improve the biocompatibility of components located in the ear canal.
© Fraunhofer IMWS / freepik
It’s All About the Surface – Simulation for Multiscale Micro and Nano Injection Molding
Project »3-ScaleSim«: Development of a Simulation Tool for Multiscale Macro-Micro-Nano Injection Molding
Many plastic products require special surface properties, such as increased abrasion resistance, antistatic properties, or improved adhesion. Such requirements play a role in numerous applications – for example, in the manufacture of injection-molded products, ranging from packaging to technical components to consumer goods. In industry, these functions are often achieved through coatings or additives by modifying or improving specific properties. However, these solutions often complicate recycling, as the materials are then no longer sort-pure.
Challenge: Functional Surfaces Without Additives
A cost-effective and more sustainable alternative is the purely physical functionalization of the surface using micro- and nanostructures. This involves creating specific structures in the micro- and nanometer range on the material surface in order to obtain certain properties. Nature provides a clear example of this: For example, a gecko can run effortlessly on smooth walls because its feet are equipped with millions of tiny hairs that are structured at the nano and micro level, thereby generating special adhesive forces. Similar principles can be exploited technically by specifically structuring surfaces. Such structures can influence, for example, the adhesion, wettability, optical properties, or friction of surfaces.
At Fraunhofer IMWS, processes are being developed for this purpose that can be used to produce hierarchical micro- and nanostructures on polymer surfaces. These structured surfaces allow properties to be specifically adjusted – without the need for additional coatings or additives. However, developing suitable structures and process parameters currently requires complex feasibility studies in injection molding. These are time-consuming and costly, and often represent a hurdle for companies.
Project Approach: Multiscale Simulation of the Injection Molding Process
In the »3-ScaleSim« project, we are developing a simulation tool that can model the injection molding process across multiple scales. The simulation is based on our MESHFREE simulation software developed at Fraunhofer ITWM. It enables cross-scale mapping of the injection molding process. This will allow feasibility studies to be carried out increasingly digitally in the future.
Three levels are considered:
- Macroscale: Component geometry and material flow in the injection molding process
- Microscale: Microstructured surfaces and their molding
- Nanoscale: Nanostructures for targeted functionalization of surfaces
In the project, our software is being expanded to include models for micro and nanoscale. The simulation tool takes various influencing factors into account:
- Surface structure design
- Material properties of the polymers used
- Injection molding process parameters
In addition, we are building a database that systematically documents the relationship between structure design, process parameters, and material properties.
Smartphone: Micro- and nanostructuring can improve the bonding of plastic components while reducing diffuse reflections on display surfaces
Hearing aid: Microstructuring and nanostructuring of earmolds to optimize adhesion properties and improve the biocompatibility of components located in the ear canal.
Project Objectives: Multiscale Injection Molding Simulation With Meshfree and Demonstrator Development
Establishment of a Cross-Scale Database
A nano-micro-macro database documents the relationships between structural design, material properties, and process parameters such as temperature or pressure in the injection molding process.
Simulation Validation
The simulations in MESHFREE are validated at all scales by experimental investigations. These experiments are carried out at Fraunhofer IMWS.
Demonstration of a complete process
At the end of the project, a demonstrator will be created that integrates the entire process – from simulation and process parameters to the manufacture of micro- and nanostructured components.
Results and Benefits for Industry With a Focus on Small and Medium-Sized Enterprises
The project result is a digitally supported overall process for multiscale injection molding. Companies can use it to assess which structures and process parameters will lead to the desired result early on in the development phase. This significantly reduces the need for costly feasibility studies.
The database-supported approach also enables continuous expansion of knowledge about structural and process influences and can also be transferred to other manufacturing processes in the future.
The simulation tool is aimed in particular at companies in the plastics processing industry that place high demands on functional surfaces and at the same time strive for sustainable production processes. The most important target industries include the automotive industry, the packaging industry, the consumer goods sector, and medical technology.
In Germany alone, the plastics processing industry comprises around 3,000 companies with approximately 300,000 employees. A large proportion of the products are manufactured using injection molding. The industry is strongly characterized by small and medium-sized enterprises (SMEs), for which complex feasibility studies often represent a particular financial and time challenge.
Example of the simulation of a mold filling process using our mesh-free simulation software MESHFREE, developed in an earlier industrial project in collaboration with VOLKSWAGEN AG. Virtual analyses help to better understand injection molding processes and optimize process parameters even before real-world testing.
Our Project Partner and more Information about the Funding
The project is being carried out in collaboration with Fraunhofer IMWS (project manager Annika Thormann) and is part of the »Fast SME-Oriented Independent Research (SME)« program. »3-ScaleSim« started on January 1, 2026, and is scheduled to run for three years.