Impact of UV radiation on the physical properties of polypropylene floating row covers
In the intensive horticulture, various ways of protected area are used for the growth of seedlings and the cultivation of vegetables in all seasons. The easiest and the cheapest form of protected area is agrotextile, which can be laid directly over vegetable crops (row cover). Agrotextiles are nonwovens which are manufactured from textile fibres which are usually of chemical origin. Textiles, used as agrotextiles require suitable tensile strength and good permeability characteristics with no significant deterioration under the influence of weather changes and UV radiation. Properties of agrotextiles depend on the fibres made of and on the type and conditions of production. The purpose of this study was to analyse the influence of simulated sun light radiation (xenon lamp) on physical properties of polypropylene (PP) nonwoven material, which is used for the production of agrotextiles. The research showed that the properties of row cover change when radiated with UV light. Tensile, tearing and bursting properties worsen after radiation and air permeability and water vapour show little increase. The changes in the properties are a consequence of changes in fibres, molecular and supermolecular structure which is exhibited in changed fibres and consequently also nonwoven properties.
Key words: Agrotextile, polypropylene, nonwovens, UV radiation, properties.