What does a blown film machine do?

A blown film machine is a type of equipment used in the manufacturing of plastic films. It is used to produce thin plastic films of various widths and thicknesses. The process involves melting plastic resin pellets and then extruding the molten plastic through a circular die.

Here's a simplified explanation of how a blown film machine works:

Extrusion: Plastic resin pellets are fed into the hopper of the machine. Inside the machine, the pellets are melted at high temperatures in an extruder barrel.

Extrusion Die: The molten plastic is forced through a circular die, typically with an adjustable opening, which determines the width and thickness of the film.

Bubble Formation: As the molten plastic exits the die, it forms a tube-like structure. This tube is immediately inflated with air, forming a bubble.

Bubble Cooling: The bubble of molten plastic is cooled as it travels upwards. This cooling process solidifies the plastic into a thin film.

Bubble Collapse: Once the desired film thickness is achieved, the bubble is collapsed and flattened by nip rollers. The flattened film is then pulled through additional rollers to control its width and wound onto rolls for storage or further processing.

Blown film machines are used to produce a wide range of plastic films, including polyethylene (PE), polypropylene (PP), and other specialty plastics. These films have various applications, such as packaging materials (e.g., bags, pouches, shrink wrap), agricultural films (e.g., greenhouse covers, mulch film), and industrial films (e.g., liners, protective films).