Prof. Dr. Peter M. Kunz is placing a cardboard box the size of a pencil case on the table in front of him. He takes off the lid, moves the box into the centre of the table and looks up with a smile. The box contains granules barely bigger than pinheads, ranging from black to reddish brown in colour. Several fountain pen nibs sit on top of these granules. The surface of the nibs is smooth and shiny, as one would expect. 

The fountain pen nibs were produced by the Heidelberg-based company LAMY. The manufacture of nibs like these, which are at the core of any fountain pen, requires a process involving over 20 steps. The process starts with punching out the raw form of the nib and its heart-shaped “breather hole” from stainless steel.. Once the company logo has been imprinted on the nib, it is turned into its characteristic shape and a small sphere is attached to the tip, forming the wear-point. The point is made of an extremely hard, wear-resistant platinum-based alloy that transfers the ink to the paper. The process is finalized by slitting the nib down the centre, which enables the ink to run down the nib by capillary action.

“The granules are made of walnut shells,” Kunz said, letting the brown granules trickle through his fingers back into the cardboard box. “The nibs are rolled through the granules during the manufacturing process.” This is done in a turning kettle. “The kettle looks just like the ones used at Christmas markets in Germany for roasting almonds,” said Kunz. The kettle also contains polishing paste, which covers the granules and slowly but surely gives the nibs their shiny appearance. “In the old days they used organic solvents, but now we use walnut granules and polishing paste, which is much more environmentally friendly.” However, the problem with the new LAMY method is that tiny walnut shell particles got jammed in the hollow spaces of the nibs. LAMY tried different cleaners and ultrasound to get rid of the particles without success and with the result that the granules had to be removed manually from the nibs using cleaning silk and oculars like those used by professional watch makers. This was a cumbersome process and sometimes required up to four people.

As a bionic scientist, Kunz looked for analogies in nature

Originally, it was not the walnut granules that brought Kunz in contact with LAMY. He was looking at the production process when the walnut granules caught his attention. “I find it always quite exciting to see how everyday objects are produced,” said Kunz explaining that he found out about the cumbersome method of removing the walnut pieces from the nibs one day as he was walking past the people that did this job. He was sure that there was a different way to do this; as a bionics specialist he went in search of solutions in nature.

“My initial idea was that there had to be organisms that degraded walnut shells,” Kunz said as he played with the granules. Fungi are known for their ability to degrade wood; they obtain their nutrients from the wood by degrading usable substances using specific enzymes. Rather than looking through textbooks in his search for suitable fungi, Kunz inspected dead walnut trees. “It seems to me to make a lot more sense to actually look for suitable fungi on the walnut trees themselves,” Kunz commented. His search was successful. He came across a fungus that is able to degrade walnut wood at moderate temperatures in our latitudes. A fungus expert provided him with information about species and genus, and Kunz searched through laboratory catalogues to find out whether enzymes of this fungus were commercially available and he then went on to prepare an enzyme mixture that would degrade the walnut shell granules in the slits of the nibs.

His second consideration related to the possibility that it may not be necessary to degrade entire granules, but that it would be enough to reduce them in size and remove the remaining traces with ultrasound. “It’s like in our mouths,” said Kunz, “where food pieces that get stuck between our teeth are broken down into smaller pieces by enzymes and are subsequently washed away by our saliva.” 

Kunz’s discovery was successful: once LAMY’s fountain pen nibs have been treated with walnut shell granules and polishing paste, they go through two immersion cleaning steps. One involves the use of Kunz’s enzyme cocktail, which makes the granules smaller. The second step involves ultrasound, which is used to wash the remaining walnut shell pieces from the nib slits. The entire process takes no longer than eight minutes. And the enzyme mixture only costs a few euros a month, virtually nothing compared to the long working hours that were previously required to clean the nibs manually. “The enzyme mixture worked efficiently from the word go,” Kunz said. Laboratory enzymes have an error rate of around 0.01 percent. Technically produced enzymes, which are less pure and hence cheaper, have an error rate of 0.02. And Kunz and LAMY can live with this. Once the nibs have been treated with enzymes and ultrasound, they are checked for scratch marks and tested for their ability to efficiently transfer ink to paper. 

And what about the enzyme mixture? Can it be used for anything else? “The enzyme mixture can in principle be used in all areas where walnut granules need to be removed from nooks and crannies,” Kunz said, replacing the lid of the cardboard box where the shiny fountain pen nibs are embedded in the brown walnut shell granules.

Contact:
Prof. Dr. Peter M. Kunz
Institute of Biological Process Engineering (IBV)
Mannheim University of Applied Sciences
Paul-Wittsack-Straße 10 (formerly Windeckstrasse 110)
D-68163 Mannheim
Tel.: +49 (0)621/ 292 - 6304 oder - 6471
Fax: +49 (0)621/ 292 - 6470
E-mail: p.kunz(at)hs-mannheim.de