1. the banana roller helps guide the film as it moves through the machine. It provides a curved surface that supports the film and ensures a smooth and controlled path, preventing the film from deviating or wrinkling during the production process.

2. the banana roller assists in the cooling of the film. As the film is drawn upwards and inflated into a bubble, the roller helps to distribute cool air evenly across the film's surface. This promotes efficient cooling and solidification of the film, ensuring its dimensional stability and preventing any undesired deformation.

3 .the banana roller plays a role in controlling the thickness of the film. By adjusting the pressure or position of the roller in relation to the film, operators can influence the final thickness and uniformity of the film. Furthermore, the arc-shaped roller helps to maintain proper tension in the film. It ensures that the film is stretched evenly and consistently, helping to achieve the desired mechanical and optical properties of the final product.

Overall, the banana roller in a blown film machine contributes to the quality and control of the film production process by guiding the film, aiding in cooling, controlling thickness, and maintaining tension during production.