Anti-Fog, Anti-Drip, Anti-Condensation and Anti-Mist

SOME FACTS ABOUT WATER Condensation: a process by which H 2 O vapors in the air are transformed from gas into liquid. Condensation occurs when warmer moist air comes in contact with cold surfaces – greenhouse film in our case. Dew-Point : the temperature to which air must be cooled to become water vapors saturated. When further cooled, the airborne water vapors condense to form liquid water (dew). When air cools to its dew-point through contact with a colder surface, water will condense on it. Ratio between Temp, Relative Humidity and Dew-Point SOURCE: Institute of Agricultural Engineering The  above table clarifies that the formation of water from vapors depends only on temperature and relative humidity. Surface Tension defined as the tendency of liquid surfaces to shrink into the minimum surface area Surface tension is measured by ...

Light The main source of light on Earth is the Sun. Sunlight provides the energy that green plants use to create sugars mostly in the form of starches, which release energy into the living things that digest them. This process of photosynthesis provides virtually all the energy used by living things.   Light goes through film Solar radiation spectrum is usually divided into three main ranges, based on the wavelength measured in nanometers (nm): Ultra Violet (UV) – from 220 nm to 400 nm. Photosynthetically Active Radiation (PAR) – from 400 nm to 700 nm; Visible light – from 380 to 700 nm – overlaps in most parts with PAR. Infra Red (IR) (Near/Middle/Far) – from 780 nm to 1 mm.   Ultra Violet (UV) UV ranges from 100 nm to 400 nm. The Ozone layer absorbs the short-wave part up to 290 nm. ...

Followed by a significant R&D efforts, production and field trails, Politiv launched in 2015 a new revolutionary line of  hydroponic   films – Diamond®. Its main features are: Highlight transmission; High and unique lightdiffusion; Highthermicity. HIGH LIGHT TRANSMISSION Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometers (nm), between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths. Photosynthetically Active Radiation (PAR) designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. This spectral region corresponds more or less ...

Solar radiation and its effect Solar radiation reaches the earth as a wide spectrum, 250 nm - 2800 nm. As can be seen in the following chart, this spectrum can be divided to three major ranges: I- UV range: 250-400 nm II- Visible range: 400-700 nm III- Infra red range: 700-2800 nm Each range has a different effect on the plastic film, plant, insects and bees: I- Infrared radiation : has the weakest radiation and is expressed as heat. This radiation has no effect on the plastic or the insects in general. II- PAR range (visible light): the plants use the visible light (PAR range) for the photosynthetic process, so it has a high influence on the plant behavior. On the plastic film it has no influence. III- The UV range: has the highest and most aggressive energy. It has huge effect on the plastic film, insects and has effect on the red ...

PAR and Plant Response Curve Just as humans need a balanced diet, plants need balanced, full-spectrum light for good health and optimum growth. The quality of light a plant receives is just as important as the quantity. Plants are sensitive to a similar portion of the spectrum as is the human eye.This portion of  the  light spectrum is referred to as Photo-synthetically Active Radiation or PAR, namely the wavelength Spectrum of about 400 to 700 nanometers. Nevertheless, the way a plant responds to light within this spectrum is very different from the way humans respond. The human eye has a peak sensitivity in the yellow-green region, around 550 nanometers. Plants, on the other hand, respond more effectively to red light and to blue light, closer to the two extremities of the visible spectrum.The graphs below show the human eye response curve and the plant response curve. ...

Diamond films PAR and Plant Response Curve Plants need balanced, full-spectrum light for good health and optimum growth. The quality of light a plant receives is just as important as the quantity . Plants are sensitive to a similar portion of the spectrum as is the human eye. This portion of the light spectrum is referred to as Photo-synthetically Active Radiation or PAR, namely the wavelength spectrum of about 400 to 700 nanometres. LIGHT TRANSMISSION THROUGH GREENHOUSE COVERS When light "strikes" the greenhouse cover, a number of things might happen to the light wave. • It could be absorbed by the film, in which case its energy is converted into heat. • It could be reflected by the film. • It could be transmitted by the film. There are two types of transmission: direct or diffused. (more…)