Some like it hot, others can’t stand the cold. Some crave the light, others prefer being kept in the dark. And air humidity is also an issue – growing edible mushrooms is a tricky business. Even more so when you do it on a large scale, like Fine Funghi from Gossau in Switzerland, which supplies the organic retail trade with, as its name suggests, fine edible fungi. KLINGER Gysi has been getting in on the act for the past three years, with a smart sealing solution for the substrate production process.
The importance of gaskets in sterilization
The collaboration between KLINGER Gysi and Fine Funghi began in 2021, when the latter encountered problems with an agitator that is used to mix the substrate for growing the mushrooms. The pasty, sawdust-based mixture with a moisture content of 60 percent is sterilized by heating it in the agitator. “During this process, the agitator must be hermetically sealed. We had a problem with the seal, so the substrate became contaminated and started to go moldy,” says Felix Steiner, who is responsible for substrate production at Fine Funghi. In his experience, a single mold spore in a 2.5 kilogram bag of substrate is enough to prevent the fungal crop from growing.
“Everything must be completely clean and sterile. That’s why we even fill and package the substrate in cleanrooms.”
Felix Steiner has a degree in agriculture and has been working at Fine Funghi for eight years, where he is responsible for substrate production.
Overcoming agitator challenges
It follows that a leak in the agitator is more than just a minor issue. So without further ado, Felix contacted Thomas Marchesi, the Area Sales Manager for gaskets and PTFE products at KLINGER Gysi. The two already knew each other, and it didn’t take long before Thomas was able to present Felix with a solution to the challenging situation. “Difficulties were presented by the agitator’s lid, which could barely be lifted, and the very thin, uneven flanges. Our aim was to replace the seal without having to completely dismantle the agitator, and to eliminate the inclination of the flange plate,” says Thomas. This was achieved with a solution consisting of eight separate sealing sheet segments that were joined together in a dovetail pattern. The result: a flat gasket with a diameter of 3.3 meters.
Contacts mentioned in the article:
Thomas Marchesi, Area Sales Manager for gaskets and PTFE products at KLINGER Gysi
The solution: KLINGERSIL C-4324 and EPDM
The material used was a special, in-house developed composite made of KLINGERSIL C-4324 and EPDM (ethylene propylene diene monomer) rubber. As Fine Funghi had already been using pressure safety valves from KLINGER Gysi for some time for its mushroom production, Felix was familiar with the products’ quality. The first seal performed well for a year before being replaced due to insufficient contact pressure in several places. Its replacement was attached to the agitator using larger bolts. It now fitted evenly and is expected to last for several years. The agitator has a capacity of four tons, and heat-treating the substrate, which takes up to ten hours, generates considerable pressure inside the vessel. This represents a stress test for the 3.3-meter diameter gasket, which it withstands perfectly thanks to its special composition. Thomas sums up the successfully concluded cooperation with Fine Funghi as follows:
“The excellent interplay between customer, field service and our technology offers the customer tangible added value and a solution that works for their particular application.”
Thomas Marchesi is Area Sales Manager for gaskets and sealing solutions at KLINGER Gysi.
Fact box
Fine Funghi
Fine Funghi is based in Gossau, Switzerland and has been a specialist in the cultivation of organic edible mushrooms for over 35 years. Its 30 employees take care of the cultivation of oyster, king oyster, shiitake, and pioppino mushrooms. The company produces around 230 tons of organic produce a year. This is supplied mainly to the retail trade, including organic food stores and, as the main customer, the Swiss cooperative and supermarket chain Coop. The main growing season for mushrooms is in autumn and winter.
Fact box
Did you know …
- … that besides a wide range of sealing solutions – including materials such as fiber-reinforced rubber, elastomer, graphite, mica, metal and PTFE –, KLINGER Gysi develops and supplies ball valves, control valves, and butterfly valves as well as fluoroplastic components?
- … that KLINGER Gysi cut the gasket from sheet material using a cutting plotter? Made of a special composite of KLINGERSIL C-4324 and EPDM, the finished product was delivered to the customer within a very short time.
- … that edible fungi, such as shiitake and king oyster mushrooms, are highly sensitive to air humidity, CO2 and room temperature? Under ideal conditions, the maximum crop yield can be up to 20 percent of the weight of the substrate used.
