Degree project – Dense and Closed Barrier Substrates

Goal 
The aim of this thesis is to research and develop dense and non-porous papers by dispersion coating treatment. The objective is to provide a substrate that maintains the important paper properties as stretch and strength while delivering a surface that optimizes the use of barrier coatings.  

Background 
At Billerud, we are convinced that working together with other companies, universities and research institutes is the best way to tap into new thinking concerning improved packaging materials in a circular approach. The purpose of the department Innovation, Product and Application Development is to create new materials that can replace fossil-based materials with more sustainable alternatives based on forest raw materials. The major challenge for cellulosic materials is to improve certain properties, such as porosity, morphology of the substrate, barriers to water vapour and other gases and to produce these materials in a resource and energy efficient way.  

Within the area of dispersion coatings and barriers, it has been identified that dense and closed surfaces secure a homogeneous barrier layer without defects, increasing flexibility and limiting the use of expensive polymers. Decreasing the amount of barrier coating will also promote the recyclability of the materials.  

The improved properties will make it possible to target new packaging markets and promote the switch from plastic to paper for segments like chocolate bars, vegetable bags and dishwashers tablet packaging.  

Main objective 
The main objective is to design surface treatment formulations that densify and close the fiber structure while being overcoatable and have minimal effect on the positive paper properties. This can be achieved by choosing the right binder mixtures and adding additives like crosslinkers and pigments.  

Project 
The work that will be carried out involves the following activities: 

• Literature study of crosslinkers to investigate their functionalities and properties to improve dispersion coatings.  
• Create experimental plans for testing interesting additives like crosslinkers in coating formulations.  
• Conduct the experiments by producing the coating formulations with additives, analysing the coating liquids for their rheological properties and coating paper samples.  
• Evaluate the coated samples by measuring key paper properties like porosity and density, studying the morphology with SEM (scanning electron microscopy) and potentially checking the barrier performance. 
• Perform a Durrer pilot coating trial with best formulations from the lab. 

Timetable 
The project preferably starts in January 2025. A detailed schedule will be defined together with the candidate. 

Location 
Location is at Billerud mill in Frövi. 

To be able to successfully contribute to this degree project, we believe that you are a master student in chemistry, chemical engineering, material science, paper engineering or equivalent. To be able to carry out the practical part of the degree project, you need to be present in our laboratories at the Frövi site. The work can also involve trips to the Skärblacka Mill.

Our values are central in our business and we believe that you recognize yourself in: we care for each other and we do what we say.

For any questions, please contact Wouter Prosper, Specialist Coating Technology at wouter.prosper@billerud.com

Candidates apply with the Billerud application system by submitting a personal letter, CV and grades. Applications are evaluated continuously, and the project will start as soon as a suitable candidate has been hired. The deadline for applications is 29 November 2024.