A Blown Film Extrusion Plant Suppliers Suppliers is an industrial manufacturing system used to melt, expand, and cool plastic resin into continuous, thin-walled tubular films. Widely used for agricultural covers, food packaging, and carrier bags, the setup operates vertically, continuously drawing molten plastic upward to form a biaxially oriented film.

The Extrusion Process

Melting: Plastic resin pellets (such as LDPE, LLDPE, or PP) are gravity-fed into the extruder barrel. A rotating screw heats and compresses the pellets, homogenizing the molten plastic.

Die Head: The molten polymer is pushed upward through a circular annular die, forming a thick-walled tube.

Blowing the Bubble: Pressurized air is injected through the center of the die, causing the tube of molten plastic to expand into a massive continuous bubble (similar to blowing soap bubbles).

Cooling & Sizing: As the bubble travels upward through a cooling air ring, it solidifies. A sizing cage stabilizes the bubble to ensure consistent film width and thickness.

Collapsing & Winding: The solidified bubble passes through collapsing guides and a set of nip rollers, flattening the tube into a double-layer film. The flat film is then edge-trimmed and wound onto large spools via a surface or center winder.