When making plans for a new greenhouse, one of the first things to determine is the principle design and its cover material. Growers will often weigh the odds between two materials: glass or polyethylene. But there is also a third material available.
Ethylene Tetrafluoroethylene, also known as EFTE, is a fluorine-based material that at first sight looks like a standard polyethylene greenhouse film. But according to Luigi Pezzon of Italian thermoplastic film manufacturer PATI, the physical and chemical characteristics of the two films are different, and EFTE can be better compared to glass than to polyethylene.
A major benefit of EFTE is the high light transmittance of the material, also in the UV bands.
“EFTE is very clear and has a high light transmission of 93%, which is higher than standard glass or polyethylene film,” Pezzon says.
It is known that more light usually means more production, so why is EFTE not more commonly used?
“That has to do with the cost of the material,” Pezzon says. “The chemical compound and manufacturing process makes EFTE a very good but expensive material. The price is more in the region of glass than in the price region of poly.”
Plenty of growers prefer EFTE above polyethylene due to its excellent light characteristics. But there is more to it.
“Despite the fact that it is more expensive, it is more durable and has a very good life span that can last for 15 to 20 years,” Pezzon says. “It is no longer needed to replace the film every few years, and due to the special chemical composition, the high light transmission does not deteriorate.”
On top of these benefits, the film has a built-in dirt resistance. The low surface tension of the EFTE film makes for a self-cleaning material that does not hold any dust or any other pollution. A rain shower is enough to clean the greenhouse, and it is not required to clean the roof with a roofwasher.
EFTE is also known for its excellent heat retention characteristics. It keeps the heat inside, which is especially interesting for cold-climate horticulture.
PATI says it has delivered EFTE material to growers in countries in Northern Europe like Holland and the United Kingdom. These growers are motivated by the high light transmission and energy saving characteristics of the film.
Pezzon also sees a future for the film in regions with sun radiation that destroys standard film.
“For growers that need to replace their film every two years due to intensive sun radiation and heat, it is worth considering EFTE,” Pezzon says. “We ship EFTE to growers in the Middle East and countries with tropical climates.”