Contact Analysis and Simulation of Rolled Plastic Film Used for Roof Ventilation in Japanese Greenhouses

Greenhouses are capable of producing a variety of high-value crops year-round. A novel Japanese greenhouse design is gaining popularity because of its automated roll-up ventilation system that is integrated into the roof. However, due to the frequent movement of the roll-up system, the plastic film deteriorates rapidly and typically lasts for only three or four months. In order to better understand the film deterioration, we studied the mechanics involved at the point of contact between the film and the metal greenhouse frame. We found that film deformation and failure were closely related to stretching and creasing, and these processes were observed at the microscopic level. An experimental device was developed to further study the damage to greenhouse film due to the roll-up movement. We concluded that the reduction in film thickness due to static loading or rolling contact was the best predictor of future film damage