Sizing from birch bark


Professor Bjarne Holmbom from the Åbo Academy University visited us on August 29 and gave an inspiring lecture on hydrophobic agents from birch bark. He visited us in connection with the fact that our licensee Tove Joelssons had a supervisor meeting with a workshop. Many thanks for sharing your research on the potential uses of birch bark.

Historically, birch bark is used to light fires, building materials, cooking vessels in the oven and as writing material. Bjarne Holmbom showed with ingenious and simple research that betulin aggregates can have a hydrophobic effect on the paper surface.

Suberin is a cork substance, stored in the bark and that the pulp industry uses as special polymers. It is similar to the lignin structure but also contains highly hydrophobic aliphatic fatty acids and is the most well-known resistant biopolymer.

Betulin is found in the cork layer of the birch bark in the form of triterpene betulinol, a kind of turpentine that gives the birch bark its white color. Betulin protects the tree against fungi and bacteria and is used today in the cosmetics industry.