Insect netting specialist SchermNed has increased the UV stability of its insect netting. This entails a further development of the special insect netting filter that the company has supplied for years. Netting with a kilo-Langley value (kly) of 1350 becomes the new filter standard. This news comes from Carl Stougie and Jack van der Voort of the Westland-based screen installation company, specialists in insect netting since 1990.

Insect netting specialist SchermNed has increased the UV stability of its insect netting. This entails a further development of the special insect netting filter that the company has supplied for years. Netting with a kilo-Langley value (kly) of 1350 becomes the new filter standard. This news comes from Carl Stougie and Jack van der Voort of the Westland-based screen installation company, specialists in insect netting since 1990.

The intensity of UV radiation is measured in Langley. Kly is the unit that indicates how much UV radiation energy falls on a square centimetre per year. The higher the Langley value, the longer a product - in this case insect netting - is able to withstand high UV radiation. "That radiation is particularly high in countries around the equator," says Carl. "However, UV radiation is higher in southern Europe, and higher UV stability quickly becomes very important."

This year, the family-owned company is supplying insect netting with its new, high UV stability for a greenhouse construction project in Saudi Arabia. "If you use netting there with typical Netherlands values up to 600-650, that netting will be worn out after three years due to the high level of UV radiation."

Lack of awareness

SchermNed supplies insect netting for horticulture in various ways. Their harmonica netting is well known, and SchermNed can also supply individual rolls or special flexible netting tents, but they have also developed their own insect netting product: the insect netting filter. "Here we were already working with Langley values up to 1000."

More and more growers are discovering the benefits of this solution, where the netting stays on the inside of the window when the vent is open. "This allows growers to grow in the same climatic conditions as without netting while also continuing to create a good climate." This is a unique observation, they emphasise, both from testing through TNO and from the experiences of what has become “a large number of growers".

SchermNed buys the latest netting with the even higher UV stability. They don’t make their own netting in Naaldwijk. They work with long-standing partners, some since 1990. "We find that not many people are aware of the importance of a high kilo-Langley value. Only when we show visual material or send an explanatory link do people realise its importance."

New standard

The question was how far you can take the Langley value with insect netting. "We put that question to our manufacturer, who can make certain additions to the netting. There is a limit to that. New technology makes it possible now, as does the market demand. There was none before. As a result, we can now supply this improved netting. Nobody supplies netting with higher values."

For the project in Saudi Arabia, SchermNed had an instruction video made in several languages for the supervisor and local people who will install the insect netting filters with the latest netting at a large project in the desert. "We used drones, among other things, to simulate the assembly in the greenhouses. Surely local guests would rather watch a video for a few minutes than read through twelve pages of instructional texts. After all, that’s what I would prefer myself," Jack laughs.

He calculates that the higher value means that even with a high UV degradation of 220 kilo Langley in Saudi Arabia, the netting will last for years. "After this period, the breaking strength is usually still 50% of the initial value, or in other words, the service life can be shorter or longer in practice depending on the situation. In the case of our SchermNed insect filter, for example, the netting is mounted inside, which also has a more positive effect on its lifespan due to sunlight (and also sand). This is a substantial improvement on what was possible until now."

In terms of harmonica netting, SchermNed was already supplying netting with a Langley value of up to 1150. "That is equivalent to 1,000 in the case of netting in our special insect netting filter, which stays on the inside of the window. The even higher value for the insect netting filter is unique. It is going to become our new standard."