Thesis subject/assignment
The goal of this project is to develop a compression dynamics model for corrugates boards in flexo post-printing processes, based on commercial FEM platforms. This work will combine FEM modelling with experimental measurements. 

Purpose of the project
Corrugated board is a commonly used packaging material for transport goods and e-commerce, while flexo post-printing is the most used printing method for this material. When running through a print nip consisting of two rigid cylinders (one covered with flexible polymeric print plate), the corrugated board is subjected to compressive deformations. Depending on the materials compositions of the corrugated board (the outer and inner liners, the fluting medium, and glue conditions), the properties of the polymer plate, etc, the stripy patterns (known as stripiness) of the prints vary. It is therefore desirable to be able to predict the stripiness tendency from the properties of the materials components of the corrugated board (outer & inner liners, fluting), glue characteristics, etc. This may pave the road for reduced or minimized stripiness in post flexo-printing.

Printing dynamics of corrugated board is an active research area at RISE. The focus of the work is to investigate the impacts of converting parameters and materials properties, such as, glueing, formation, glue absorption / penetration, on printing stripiness.

The method developed in this project is expected to provide industry with a tool for product development. To achieve this, you will work together with other researchers and lab engineers who will help you to start up your project and help you on the way.

Project activities will include

• Literature survey on state-of-the-art in the frame of the project objectives.
• Analysis of compressive deformation of corrugated boards (possible support from RISE colleagues for experimental measurements).
• Development FEM models for flexo post-print systems, taking into account viscoelasticity of the corrugated board.
• Printing dynamics simulation of printing systems having different materials compositions / combinations.
• Analysis of results – to find the optimal materials combinations for minimal stripiness tendency.
• Final report (Master’s thesis).

Who are you?
We are looking for one master student within the area of Solid Mechanics or Physics. Good command in numerical analysis, modelling and simulation is essential. The start date is Jan. 2026 or based on mutual agreement.

Terms
The master thesis work will be carried out at RISE in Stockholm or Kista, corresponding to 30 ETCs. For an approved thesis project worth 30 credits, we pay
a compensation of 39,990 SEK. For more details contact Roger Källberg, roger.kallberg@ri.se, 010 510 51 75.

Supervisors

Li Yang (li.yang@ri.se), 010 228 45 22

Gustav Marin (gustav.marin@ri.se), 010 228 45 45.

Welcome with your application
The application deadline is Oct. 20^th, 2025. The selection process will begin immediately after the deadline.