UCLA

Punched membranes as fine pore diffuser material have become available in the last ten years because they are more efficient. Heat, moisture and UV light are three main factors causing degradation of plastics and rubber membranes. In order to better understand the impact of sunlight on membranes, a series of outdoor tests were conducted on actual membranes. Results of this experiment showed that heat decreased hardness values; existence of UV light resulted in decreased modulus values; heat only had very slight effect on thickness and weight. To prevent membranes from degradation, it is suggested that they are stored in water as deep as at least 24 cm and they are covered with UV filter, especially when the weather is hot and UV light is strong.