Procedure for Plastic Bag Manufacturing

Manufacturers produce plastic bags through a process called blown film extrusion. Blown film extrusion produces many common products, including garbage bags, grocery bags, bread bags and other plastic packaging, according to the Jobwerx Manufacturing Network.

Extrusion

Plastic bags begin as plastic pellets. These pellets move through a heated barrel called an extruder where both heat and friction soften the plastic. Air then blows the plastic upward into a tube-shaped die, creating an air-filled plastic bubble.

Shaping

Fine control of the blown film extrusion process allows manufacturers to apply any thickness or size to the plastic film. Factors such as the amount of air blown into the tube, the speed of the extruder and the motion of the rollers that send the filmy material onward all help determine the final qualities of the plastic.

Finishing

The newly created plastic tube proceeds to a bag-making machine, either directly or through a set of rollers. The bag-making machine heat-seals one end of the tube together to create the bottom of the bag, while a cutter at the other end forms a precise, even opening.

References

• Jobwerx Manufacturing Network: Extrusion (Blown Film Extrusion)