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GREENHOUSE CLADDING PLASTICS
POND / CANAL
LINING FILMS
MULCH FILMS
SOLARIZATION FILMS |
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| GREENHOUSE FILMS |
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Essen Multipack Limited is pioneer of
multilayer wide width agricultural films in India. The company
has a wide range of products viz. Greenhouse films, Mulch films,
CAP covers, Pond/Canal liners available in different thickness
and width up to 10 meter.
These Multilayer films are specially formulated based on inputs
of experts from the plastic as well as floriculture industry.
Agricultural films are based on best quality raw materials and
internationally reputed additives/master batches. The films
are manufactured on a state-of-the-art wide width multi-layer
blown film extrusion line under supervision of experienced personnel
in plastic processing technology. ESSEN has an ultra modern
laboratory well equipped with the latest testing facility. Each
lot of film is tested before delivery and the supplies are made
along with the test certificates. The quality assurance system
of ESSEN is certified by BVQI as per ISO 9001:2000 norm. |
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| The company manufactures following specialized
products in the category of agricultural application films: |
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C3201 – Clear, U.V. Stabilized
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D3202 – Diffused, U.V. Stabilized |
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N3203 – Anti–Sulphur, Diffused,
U.V. Stabilized |
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CN3204AF – Anti–Fog, Anti–Dust
and Anti–Sulphur, U.V. Stabilized |
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| BESIDES THESE REGULAR PRODUCTS; WE CAN
ALSO SUPPLY FILMS AS PER CUSTOMERS SPECIFIC REQUIREMENTS. |
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| INTRODUCTION : |
In the past few decades use of plastic
films for greenhouse has gained prominence across the globe.
The advantages offered by them such as lightweight, translucency,
flexibility, toughness, hydrophobic nature and durability, make
plastics films the most preferred material for cladding of greenhouses.
Different types of plastic materials such as Poly Vinyl Chloride
(PVC), Poly Carbonate (PC) and Low Density Polyethylene (LDPE)
are commonly used for cladding of greenhouse structures. LDPE
remains the most popular of all plastic material because of
its features, ease in availability and economics. |
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| REQUIREMENTS OF POLY FILMS FOR GREENHOUSES
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| DURABILITY |
Polyethylene films when exposed to outdoor
environment for longer duration are prone to degradation as
a combined effect of sunlight, heat and oxidation. Interaction
with the Sulphur or Halogen based Crop Protection Chemicals
(CPC), further accelerates this degradation process.
Special chemical additives are incorporated into the polymer
matrix to provide a longer lifetime in case of greenhouse films.
These additives are known as U.V. Stabilizers, when used along
with antioxidants, protect the poly film from photo as well
as thermal degradation.
The two main types of U.V. Stabilizer systems being used are: |
- HALS (Hindered Amine Light Stabilizer) + UV absorber Films
based on the above package are colorless / translucent in
appearance, stabilizes the harmful U.V. radiation form entering
in to the Greenhouse and allow maximum transmission of light.
For chemical resistance against halogens or Sulphur, it
is necessary to include a co-stabilizer in this system.
- Nickel-quencher + UV absorber Films stabilized with above
package are greenish / yellowish in appearance. This shade
gives a slightly hazy effect thus reducing the intensity
of direct light transmission. This stabilization system
gives excellent U.V. Stabilization also provides good protection
against action of CPC’s. This property is also sometimes
termed as Anti–Sulphur
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| MECHANICAL PROPERTIES |
The mechanical strength of film is a function
of polymer and the processing parameters. Incorporation of right
proportion of EVA (Ethylene vinyl acetate), higher alpha olefin
based LLDPE (linear low density polyethylene) or mPE’s
(metallocene LLDPE) can significantly improve the film properties
like impact strength, tear resistance, flex crack resistance,
environmental stress cracking resistance and tensile strength.
As a result there is appreciable increase in the service life
of film.
For incorporating these high performance polymers, the film
plant should be designed with latest technology like Co-Extrusion.
It is also important that the process parameters are optimized
for best results. |
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| PROPER LIGHT TRANSMISSION |
Proper light transmission filtering, out
the harmful Ultra Violet (U.V.) radiation is very essential
for optimized growth of the crops inside the Greenhouse.
The photosynthesis activity in plants is directly proportional
to the amount of light. Higher light transmission enhances the
growth of plants. Therefore it is crucial to select the right
combination of polymer and specialty additives, to get maximum
light transmission. This is more significant for greenhouses
located in colder climates where availability of daylight is
limited.
The ultra violet radiation is harmful for the plants growth.
As well as when the protective polyethylene films are exposed
to outdoors environment for longer duration are prone to degradation
as a combined effect of sunlight, heat and oxidation. Interaction
with the Sulphur or halogen based crop protection chemicals
(cpc), further accelerates this degradation process.
Special chemical additives are incorporated into the polymer
matrix to provide a longer lifetime in case of greenhouse films.
These additives are known as U.V. stabilizers, when used along
with anti-oxidants, protect the film from photo as well as thermal
degradation. At the same time helps in proper and maximum light
transmission. |
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Improper light
transmission
Harmful U.V. entering inside |
Proper Light transmission
Not allowing harmful U.V. transmission |
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| DIFFUSION |
Direct sunlight is scattered thus eliminating
the “shadow” effect and avoiding “sun burns”
or “scorching".
All the major commercial floriculture centers located in tropical
climates can benefit from this, where the temperatures are relatively
higher in summer, the high intensity of light is undesirable
as it causes heat build up within the greenhouse. Many varieties
of crops are unable to withstand the heat and often a burning
effect is observed in such plants also because of the high intensity
direct sunlight.
To reduce the intensity of light, shade-nets are used in greenhouses.
It is a common practice to apply a thin coat of white wash over
the clear film in summer seasons to reduce the intensity of
the direct sun rays. However this has an adverse effect on the
lifetime of the protective film.
For such severe climatic conditions it is advisable to use DIFFUSED
films. Incorporation of special mineral fillers in the polymer
can give DIFFUSION of light without causing significant hindrance
to total light transmission. This causes scattering of the direct
rays thus preventing the burning effect as well as eliminates
shadowing of upper foliage of the plant on the lower foliage,
thus promoting equal feeding to all the parts of the plant.
It is reported that diffusion of light has a positive effect
on growth of plants as more light is available and shadowing
effect is eliminated. The amount of diffusion of light can be
altered according to specific requirements by modification in
the combination of polymers, stabilizers and special fillers. |
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Direct Sun rays
falling on the crops burns them and also the lower foliage
does not get the proper light comparatively |
The direct rays
are scattered thus intensity is reduced and also the
lower foliage gets more light light as the shadow effect
is eliminated |
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| ANTI-FOG / ANTI-DRIP EFFECT /
ANTI-CONDENSATION |
Water droplets forming inside due to condensation
causes hindrance to proper light transmission and falling water
droplets causes spots and diseases on the flowers.
Condensation of water vapor, results into formation of droplets
on the inside surface of greenhouse film. This has a negative
effect on the crop because of following effects |
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- Reduction in morning light transmission.
- Making plants more prone to diseases, caused by droplets
falling on the leaves and stem.
- Burning of petals and leaves, as the intensity of rays
passing through the droplet is increased as they act like
a lens.
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Special additives are incorporated in
the material formulation to alter the surface tension of film.
The reduction in surface tension leads to formation of a very
thin film of water, which subsequently runs down along the slope
of film into the gutters.
The anti-fogging or anti-drip effect is function of time and
the environmental conditions. |
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Water droplets
formed due to Condensation hinders the light transmission
and also drips on the flowers causing spots & diseases
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Water droplets
are not allowed
to drip and runs into gutters |
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| THERMAL EFFECT - THERMICITY |
As the temperature out side the greenhouses
is lower than inside during nights, the heat gathered inside
during day is lost to outside by irradiation from hot place
(inside) towards cold place (outside).
During the nights the temperature outside greenhouse falls below
the temperature within the greenhouse. Also in cold climatic
conditions during the night the temperature outside falls below
the temperature within the greenhouse. As a result there is
loss of heat from the greenhouse by radiation towards outside
and the greenhouse temperature is reduced. Actually it is the
Infra red radiation absorbed by the bodies inside the greenhouse
that travels to the colder areas. To prevent this radiation
loss, mineral based additive or special polymers are incorporated
within the film.
This thermic effect by the films helps to maintain the temperature
within the greenhouse and insulate the plants from the cold
injuries and temperature variations. Above all saves a lot on
the heating expenses. |
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Under Non-thermic
film
there is radiation loss |
Under thermic films
the
radiation loss is not allowed |
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| ANTI-DUST |
Polyethylene films have a tendency to
attract dust particles. Over a longer period of exposure considerable
accumulation of dust leads to reduction in light transmission.
This has a negative effect on growth of plants resulting to
lower yield and slower growth.
Special additives, which migrate to the surface of film, can
prevent accumulation of dust. This function is a function of
time and ambient conditions. |
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| ADVANTAGES OF MULTI LAYER GREENHOUSE FILMS |
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| Conventional films |
| Monolayer / Single Layer, 200 micron UV
stabilized LDPE film |
| LDPE + UV stabilizer + All the specialty
additives |
All the UV stabilizers and additives are
combined into one single layer along with the base polymer.
Majority of additives are known to interact with each other
leading to reduction in their efficiency thus effecting on the
performance.
Imperfections in surface of film or some impurity in polymer
/ additive master batch has a direct negative effect on the
film properties. |
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| The Multi Layer films |
Multilayer film technology offers scope
for incorporation of different type of functional additives
for different layers. Thus films can be tailor made to meet
all the inside as well as outside performance requirements as
explained earlier.
The different types of performance enhancing additives being
used selectively for respective layers are as follows: |
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| OUTER : |
Anti static agent: |
ANTI DUST+ UV Stabilizers & Nickel-Quencher |
| MIDDLE : |
Light diffusing additives: |
DIFFUSED+UV Stabilizers & Nickel-Quencher
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| INNER : |
Anti fogging additives: |
ANTI DRIP+ UV Stabilizers & Nickel-Quencher |
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The dosage levels of additives can be
optimized according to each layer thus resulting into significant
cost savings.
Any undesirable defects in one of the layers of film resulting
due to any impurity in polymer/additive master batch can be
masked with the remaining two layers.
Significant improvements in mechanical properties can be achieved
with addition of minor component of high performance polymers
in individual layers.
Multilayer films are found to demonstrate superior moisture
barrier properties.
Co-extrusion technology for the Multilayer films has the best
scope for lading the film with these requisite properties. As
a product of latest technology & inculcation of various
specialized functions like UV, IR / thermal stability, Diffusion,
Anti-Fog, Anti-Sulphur, Anti-Dust, etc. The Suncool Multilayer
films work more effectively than the ordinary films. |
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