Event details
Agricultural Film 2008
Conference from 2008-02-18 to 2008-02-20
City/Country: Barcelona, Fira Palace Hotel, Spain
Contact: Dr Sally Humphreys (sh@amiplastics.com)
Content/Topics
In Europe polyethylene holds by far the largest share of the market followed by PVC, PP and a small amount of other materials. In Japan and other parts of Asia more PVC is used and the technology for producing wide films (2-3 m) is well established there. In contrast, Europe developed extrusion blowing of wide polyethylene film (2-20 m). Recent developments in polymer materials include biodegradable materials and metallocene polyolefins (which allow the film gauge to be reduced). The film structure has a direct effect on crop yield and quality.
Mulch films come in a variety of colours. Functions include: regulation of soil temperature, weed suppression (this also reduces damage to roots by cutting the requirement for tilling), retention of soil based pesticides, maintenance of bed shape and drainage, pathogen barrier, water retention and reduction in fertilizer leaching. The colour controls the reflection of light back onto the crop and can increase yield and quality.
Films are used to reduce the damage to crops caused by soil borne pests. In a process known as solarisation, film is placed as a cover on the soil and the concentration of sunlight generates high temperatures in order to reduce the viability of weed seeds, fungi and other pests such as nematode worms. Solarisation with anti-drip films has controlled crown rot in tomatoes, while double mulch with black film and anti-drip film controlled sudden wilt of a melon crop in the Middle East. Reflective polyethylene mulch has reduced aphid and mosaic virus damage in melon crops in California.
The formulation of compounds for Agricultural Film can be very refined. Besides the requirement for anti-UV properties and established stabilisers such as HALS, many films are specifically formulated to transmit or absorb specific wavelengths of light. This can be used to enhance the growth of specific crops and/or limit the growth and development of weeds and other pests. Research in this area includes a photoselective red luminescent additive that shifts light from the UV spectrum to wavelengths used in photosynthesis. This can increase crop productivity and as an additional benefit may also limit some pests.
Films are also employed to cover soil during fumigation; HDPE is much less permeable than LDPE to chemicals such as methyl bromide. Newer high performance, very impermeable film (VIF) can help to reduce the amount of fumigant required, reduce off-gassing and retain it for longer periods. Multilayer structures are in use with typically a polyamide or EVOH layer in an LDPE sandwich, and also metallised films. Tear resistance and other handling properties must meet the standards of traditional film materials.
Silage wraps (generally stretch film) are required to be airtight and resistant to heat and solar radiation.
LDPE for greenhouses is compounded to improve infrared opacity using mineral fillers or blends with other polymers, so that heat is retained. Visible light transmittance is an essential property for these films – anti-dripping formulations cut condensation and careful additive selection can reduce dust accumulation on the film surface. Experiments with greenhouse film in a Saharan environment in Algeria have emphasised the issue of abrasion resistance to sand and wind – multilayer film (EVA between two layers of LDPE) performed better than PE alone.
Waste plastic is an issue worldwide. Recycling of agricultural film is being studied intensely – the issues are recovery, chemical and soil contamination of the plastic. A new EU project, Labelagriwaste, is bringing together companies from the supply chain to develop a collection and processing system. In the US, research includes using the plastic as a fuel source. Compostable materials are being tested as an alternative for some applications to remove the need for recovery.
Mulch films come in a variety of colours. Functions include: regulation of soil temperature, weed suppression (this also reduces damage to roots by cutting the requirement for tilling), retention of soil based pesticides, maintenance of bed shape and drainage, pathogen barrier, water retention and reduction in fertilizer leaching. The colour controls the reflection of light back onto the crop and can increase yield and quality.
Films are used to reduce the damage to crops caused by soil borne pests. In a process known as solarisation, film is placed as a cover on the soil and the concentration of sunlight generates high temperatures in order to reduce the viability of weed seeds, fungi and other pests such as nematode worms. Solarisation with anti-drip films has controlled crown rot in tomatoes, while double mulch with black film and anti-drip film controlled sudden wilt of a melon crop in the Middle East. Reflective polyethylene mulch has reduced aphid and mosaic virus damage in melon crops in California.
The formulation of compounds for Agricultural Film can be very refined. Besides the requirement for anti-UV properties and established stabilisers such as HALS, many films are specifically formulated to transmit or absorb specific wavelengths of light. This can be used to enhance the growth of specific crops and/or limit the growth and development of weeds and other pests. Research in this area includes a photoselective red luminescent additive that shifts light from the UV spectrum to wavelengths used in photosynthesis. This can increase crop productivity and as an additional benefit may also limit some pests.
Films are also employed to cover soil during fumigation; HDPE is much less permeable than LDPE to chemicals such as methyl bromide. Newer high performance, very impermeable film (VIF) can help to reduce the amount of fumigant required, reduce off-gassing and retain it for longer periods. Multilayer structures are in use with typically a polyamide or EVOH layer in an LDPE sandwich, and also metallised films. Tear resistance and other handling properties must meet the standards of traditional film materials.
Silage wraps (generally stretch film) are required to be airtight and resistant to heat and solar radiation.
LDPE for greenhouses is compounded to improve infrared opacity using mineral fillers or blends with other polymers, so that heat is retained. Visible light transmittance is an essential property for these films – anti-dripping formulations cut condensation and careful additive selection can reduce dust accumulation on the film surface. Experiments with greenhouse film in a Saharan environment in Algeria have emphasised the issue of abrasion resistance to sand and wind – multilayer film (EVA between two layers of LDPE) performed better than PE alone.
Waste plastic is an issue worldwide. Recycling of agricultural film is being studied intensely – the issues are recovery, chemical and soil contamination of the plastic. A new EU project, Labelagriwaste, is bringing together companies from the supply chain to develop a collection and processing system. In the US, research includes using the plastic as a fuel source. Compostable materials are being tested as an alternative for some applications to remove the need for recovery.
(Description according to organiser information)
Organiser
AMI - Applied Market Information Ltd.
United Kingdom
One Brunswick Square (Third Floor)
BS2 8PE Bristol
United KingdomEmail: info@amiplastics.com
Phone: +44(0)117 924 9442
Fax: +44(0)117 311 1534
