Master's thesis:Cracking of fibre-based packaging during conversion

RISE is the Swedish Research Institute and innovation partner. In international collaboration with industry, academia and the public sector, we ensure the competitiveness of the business community and contribute to a sustainable society. Our 2,800 employees support and promote all manner of innovative processes. RISE is an independent, state-owned research institute that offers unique expertise and about 100 testbeds and demonstration facilities, instrumental in future-proofing technologies, products and services.

Background
One of the central functions of food packaging is to protect the food from the environment and thus increase the shelf life of the food. Fossil-based polymers are currently used in food packaging to create barriers against oxygen and moisture.

Paper and cardboard are porous materials. Therefore, these are coated with an impermeable barrier to protect the contents of the package from oxygen and moisture, as well as to protect packaging materials from moisture, grease and oil. In order for the layer to function as a barrier, it need to form a continuous film free of defects.

RISE has been working on cracking during converting of paper and board for a long time and has developed methodology to test how the barrier properties are affected during folding of paper and during creasing and folding of board. The thesis will use this methodology to investigate how different pre-treatments of paper affect cracking during conversion.

Target
The aim of the degree project is to investigate how different pre-treatments affect cracking of paper during conversion. This includes explaining the influence of different types of surface bonding on cracking based on measurement data and theoretical models.

What skills will you develop during the degree project
Preparation of barrier coating formulations and coating with barrier coating. Practical and theoretical knowledge of converting of fiber-based packaging materials. Experience from working in a research environment focused on biomaterials and industrial research in the field of packaging.

Who are you?

We are looking for a master's student in chemical engineering, materials engineering or equivalent who can complete their degree project in the spring of 2026. It is important that you are interested in combining theory with laboratory work.

Activities
The work includes both practical and theoretical elements and will be carried out in RISE laboratories in Stockholm and in Kista. Part of the work might be carried out on site at one of our industrial partners.

The work will include the following elements:

1. Preparation of three different starches (one neutral, one oxidized and one cationic starch) and the production of surface-sized paper samples.
2. Preparation of PVOH formulation from powder and barrier coating of paper.
3. Characterization of mechanical properties of coated and uncoated samples by tensile tests.
4. Characterization of the adhesion between the paper and the PVOH layer by peel test or other suitable method.
5. Contact angle measurements with three different liquids on pre-coated and on PVOH coated papers. Calculation of surface energies and the adhesion work between the components.
6. Converting paper and measuring barrier properties before and after folding by grease penetration or other suitable method.

Terms
Scope: 30 ECTS (20 weeks, full-time).
Location: RISE, Stockholm Drottning Kristinas väg 61. Part of the work can be performed at one of our industrial partners.
Start: According to agreement, at latest Jan 22
Compensation: SEK after thesis has been approved
Supervisors: Peter Rättö, RISE, , Johan Alfthan, RISE, , Kristina Junel, RISE, , Cecilia Rydefalk,
Application deadline: November 17, Applications will be processed on an ongoing basis.

Welcome with your application