Premature damage (Not related to UV Degradation) of Greenhouse film is a major issue among greenhouse farmers in India. This premature damage happens due to degradation at the contact point with metal as follows:
- Metal used in greenhouse construction is Zinc coated.
- Zinc tends to migrate from the metal to the plastic at the contact point.
- Metal also gets heated due to adsorption of IR.
- Warm meatal transfers heat to the plastic in contact.
- The greenhouse film gets warm during the day and cool during night.
- Alternative heating and cooling tends to make plastic brittle and weaker at contact point…..