Israel is world-renowned not only as a startup nation but also as a country with advanced agriculture. This agriculture is direly needed in a densely populated and dry country with large swaths of desert land or land verging on the desert. These technologically advanced agricultural solutions are also widespread throughout the world, providing the benefits of increased output per area, energy and water savings, and enabling growing crops in other than their natural habitat.
Greenhouses for controlled growing conditions
Historical evidence points to the use of closed spaces to maintain desired environmental conditions as far back as the Roman Empire when Roman farmers grew vegetables in structures built of cloth and sheets. Going forward these were replaced with glass as a suitable greenhouse raw material owing to its main properties: transparency and thermal insulation. Glass greenhouses have not yet disappeared, however, several no less attractive alternatives are now available which are both lightweight and can withstand breakage.
Plastic-based greenhouse coverings
What types of plastic sheets and panels are replacing heavy and breakable greenhouse glass?
Flexible Polyethylene (PE) Sheets
Greenhouses with plastic sheets stretched on metal structures or covering crops growing in the soil are not an uncommon sight along Israel’s roads. These PE sheets enable the selective passage of light and heat, and are affordably priced, and are easy to deploy owing to their thin thickness and lightweight. However, they have a short lifespan and are therefore suitable for short-term projects of 1-3 years.
Polycarbonate (PC) panels
PC panels are the ideal solution when you need a lightweight panel that combines mechanical durability over time, excellent heat transmission, and superior insulation properties. At Plazit-Polygal PC panels are our expertise. Similar to double-glazed windows, PC panels are natural thermal insulators owing to their unique hollow structure which uses air as an additional insulating layer. Add the mechanical properties of PC (also known as transparent steel) and the end result is a greenhouse with transparent and very strong walls, but without the massive construction needed when building glass greenhouses. Moreover, compared to glass, PC panels provide excellent mechanical durability at an affordable price. Finally, they can be received with interesting functionality.
A range of greenhouse PC panel coatings
At Plazit-Polygal we provide a wide range of PC panels. Every panel is adapted to the requested application, not only in terms of its mechanical structure but also with respect to the required coating. Thus we match the coating to the needed properties depending on crop type, project location, and cost.
UV radiation protection
All Plazit-Polygal PC panels come with UV protection coating and a 10-year warranty. In certain cases, panels can be manufactured with a thicker protective coating which then extends the warranty to 15 years.
Anti-vapor and anti-fog coating
Water vapor tends to accumulate on the PC panels and drip downwards. This may impair the diffusion of light reaching the leaves, as the water droplets function as a lens. Furthermore, the water vapor reduces the passage of light into the greenhouse, while also inconveniencing workers or guests inside. With the anti-fog (AF) coating these problems are solved and the panels remain transparent. You’ll even find them in many commercial gardening centers where they keep the greenhouse visitors dry and happy.
Controlling the number of light rays
The composition of light entering the greenhouse can be controlled with a selective layer of coating for the passage of light. For example, in hot countries with strong sunlight, we will want to spread the light and prevent direct sun rays on the plants. IR blockers can also be integrated into the panel in order to maintain a suitable temperature by preventing the entry of heat energy. Another coating can in fact prevent the penetration of visible light, which is why panels with this coating are suitable for fish farms in the aim of preventing the growth of algae in the fish pools.
As an agricultural crop, medical cannabis requires especially close monitoring, which is why artificial lighting is used. Our PC panels can also meet this need by using a triple composition comprised of a middle layer that contains a black pigment for panel opaqueness, a reflective white layer facing into the greenhouse that provides optimal usage of the artificial light within the structure, and another, external, white layer that reflects IR radiation and prevents overheating.
Smart and inexpensive solutions for agriculture under increasingly harsh conditions
Global warming and desertification are not only making extensive areas hotter and drier but also hindering agricultural activity in these regions. Our PC panels constitute one of the foundations for sustainable agriculture in these areas. We are proud of our continued development of this field and of our contribution to a world that can therefore produce more from limited land resources, while also using less water and energy.
