Master Thesis Project: Method development in printing processes - Hiring in process/Finished, not possible to apply

Background
Flexography is a printing technique used to print everything from packages to electronics. It is a contact method for ink transfer onto a substrate utilizing relatively soft polymeric printing plates in rolling contact. The speed in a modern printing press is around 600 m/min and the time for ink to transfer from printing plate to substrate is counted in milliseconds. To add to the complexity of the process it involves the compression of several complex polymeric materials together with the substrate in the print nip. Materials whose relative topological, mechanical and surface chemical properties affect the printed result. This is therefore a field with many unanswered questions.

The thesis project is a part of a larger project concerned with printing dynamics and forced ink absorption in flexographic printing. The quality of the print, i.e. how well the ink has been transferred to the substrate, can among other things be a result of how high the pressure in the print nip is and how long the printing plate is in contact with the substrate. To study the influence of the process parameters and material properties, a pressure sensor will be placed in a laboratory printing press to measure the pressure while printing.

Purpose of the project
To develop a method to control and manipulate the pressure pulse in a laboratory printing press. This will be used to connect the process parameters in the printing press with the pressure pulse and the printed result.

Project description

• Be an integral part in developing the existing experiment setup.
  • Show the pressure pulse in real time
  • Calculate contact time in real time
• Combine speed, pressure and the thickness and stiffness of the printing plates in the laboratory printing press to manipulate the pulse, nip length and contact time
• Measure with and without substrates
• Measure with and without ink

Project goal

• Master thesis project:
  • Integral contribution to method development
  • Connect the process parameters in the lab press to the shape of the pressure pulse
• Additional goals in the project:
  • Connect the pressure pulse shape to the printed result

Skills you will develop in this project
Experimental method development. Experience of working in a research environment aimed towards biomaterials and the paper industry.

Who are you?
We are looking for a master student in Engineering Mechanics or equivalent, who can complete their degree project during the spring 2022. You need to be comfortable working with Matlab. An interest in material mechanics, method development and experimental research is also a requirement.

About RISE
The project will be carried out at RISE – Research Institutes of Sweden, an independent government research institute. The specific placement will be mainly the lab at Drottning Kristinas väg 61 in Stockholm.

Contact
Cecilia Rydefalk, Industry doctoral student RISE & KTH, +46 10 228 44 66.