From Greenhouse Coverings
Superior Strength: A new generation of super-tough films has been introduced by Plastika Kritis in recent years using special high-strength polymers. These films offer additional safety in areas with very strong winds, or significant economy as they can be produced at a lower thickness than regular films while maintaining the same or still higher strength. Light Transmission: High light transmission is absolutely essential to plant growth. Experience in production, quality of equipment and selection of materials; ensure that LUMITE films have the maximum light transmission.
Such useful features are:
- Life of film
- Strength of film
- Light Transmission
- Thermal Effect
- Disease Control
- Cooling Effect
- Anti-Mist Effect
- Anit-Drip Effect
- Light Diffusion
Sun Master greenhouse films are protected with one of the following 'systems' of UV-stabilizers:
- Selected HALS* + UV-absorbers
- Selected HALS + UV-absorbers + co-stabilizers for improved resistance to agrochemicals
- Ni-quencher + UV-absorber
- Special chemical resistant HALS + UV-absorbers
- Choice of the best UV-stabilizing system depends, mainly, on the cultivating habits and the use of agrochemicals.
- HALS: Hindered Amine Light Stabilizers
SunMaster offers special 3-layer thermic films, containing a combination of EVA and Infra-Red additives skillfully structured in the 3 layers, which absorb the Infra-Red radiation and reduce heat losses throughout the night.
The advantages of thermic films are:
- Protection from frost and low temperature.
- Smoother temperature drop and higher night temperatures overall.
- Reduced energy consumption for heating.
- Higher crop yield.
- Earlier harvesting.
- Better quality of crops.
In many areas of the world there is growing requirement for films that cut-down excessive heat during day-time and maintain a cooler environment in the greenhouse. Particularly in the 'tropics', in areas with strong sunlight and hot weather as well as in nurseries and for shadow-loving ornamental plants, the 'cooling effect' is becoming more and more a requirement.
SunMaster offers special types of films, which reflect and/or absorb the Near Infra-Red (NIR) Radiation, the part of solar spectrum carrying most of the heat entering a greenhouse in day-time and which is otherwise useless for plants growth, thus reducing the heat inside the greenhouse during the day. It has been demonstrated that the higher the outside temperature, the larger is the temperature difference achieved by use of 'cooling' films.
Our range of 'cooling' films includes:
- High diffusion films
- Our special double-effect 'silver' film (cooling during day, more thermic during night)
- Selective interference' films
Note: after cold winter nights, temperature rise in the morning may be a little slower under 'cooling' films than under conventional PE films.
Droplets formed at the inside surface of greenhouse films due to water-condensation have negative consequences on plant quality and growth, as they reduce light-transmission by 15-30% and increase the incidence of certain diseases.
SunMaster is supplying 'anti-dripping' films that contain special additives which eliminate droplets and form instead a continuous thin layer of water running down the sides.
Anti-dripping films, when used properly, offer the following benefits:
1. More light in the greenhouse
- Higher crop yield
- Earlier harvesting
- Better quality of crop, higher commercial value
- Fewer diseases
- Reduced need for pesticides
Important note: Anti-dripping films are mainly recommended for well ventilated and/or heated greenhouses, with adequate inclination of the roof. The 'anti-dripping' effect lasts for up to 2 years, as the additives function by migrating to the surface of the film and are slowly washed out by water. Under certain circumstances there is mist (fog) formation in greenhouses covered with anti-dripping films. Such mist usually occurs at sun-set and dawn and is undesirable as it could cause damages to the plants. It is strongly advisable to ventilate and/or heat the greenhouse immediately, to remove this mist. Due to the complex mechanism of its activity and to the variety of parameters affecting its function, LUMITE does not provide a warranty nor assumes any liability on the effectiveness and duration of the anti-dripping effect.
To allow the use of anti-dripping films, with all their benefits, without fear of the mist (fog) that is sometimes formed during sun-set and dawn in greenhouses covered with such films, we have developed anti-dripping films with a special anti-mist function that reduces or prevents the formation of mist.
Note : Due to the complex mechanism of its activity and to the variety of parameters affecting its performance LUMITE does not provide a warranty nor assumes any liability on the effectiveness and duration of the anti-mist effect.
Light from the sun passing through a greenhouse film and entering a greenhouse is split into direct and diffused. Light diffusion causes a film to look hazy to human eye-this doesn't mean, however, that the film is less transparent. The PAR (photosynthetic active radiation) received by plants is the same.
It is now generally accepted that diffused light has a positive effect on plant growth, especially for spring and summer crops and in areas with strong sunlight.
Light diffusion reduces shadows, ensures more uniform distribution of light in the greenhouse so that it reaches even the lower parts of the plants, prevents burnings and offers a moderate cooling effect.
LUMITE has the know-how and produces films with more or less diffusion, according to the specific requirements of each area and crop:
- Crystal clear films with very low diffusion (maximum direct light).
- Films with medium diffusion
- Films with very high diffusion
The choice of the most appropriate level of diffusion depends on the climate of the area, the crop and the season(s) of growing. PLASTIKA KRITIS' experts are at the disposal of our customers to consult on the most suitable level for every particular case.
Disease Control Effect
We have developed a range of special disease control films, which contribute efficiently in 'Integrated Pest Management' and help to reduce the usage of pesticides.
An important type of disease and insects control films is 'UV-blocking' films, which absorb UV-radiation up to 390 nm, thus achieving:
- Reduction of the population of whiteflies, thrips, miners, aphids and other insects in greenhouses, thereby also reducing the viruses which are vectored by these insects.
- Control of the spread of certain diseases (such as botrytis), by reducing the sporulation of the relevant pathogenic fungi.
- Reduction of 'blackening' of red rose petals, thereby increasing their commercial value.
- Note:“UV-blocking” films should be used after prior testing when bumble-bees are used as pollinators or when growing eggplants or other purple flowers or crops. A number of other parameters, such as temperature and humidity, enhance the development of diseases. The plastic film alone may not control diseases, it can, however, contribute to their control, when used in conjunction with other suitable methods.