How Is Bubble Wrap Made?

Extruder

Bubble wrap begins as small beads of polyethylene resin. These beads are fairly small, typically the size of a small piece of gravel. The manufacturer sends the beads into a machine known as an extruder. The extruder looks like a large and skinny can. It contains a screw on one side that runs from one end to the other. A machine turns the screw, which causes the temperature to rise. As the temperature rises, the heat inside the extruder rises. The resin begins to melt and turns into a liquid type product. At the end of the cylinder there's a thin slot, which forces out the liquid. It actually causes the liquid to emerge as two thin sheets of plastic. The sheets are almost completely clear and contain a small pocket of air in the middle.

Drum

The sheets then run through a specially formed drum. The top layer of the sheet attaches itself to the drum and spins around the entire surface. This drum contains different holes of a uniform size and shape, typically a small circle. Some companies use different sized holes on the drum, which creates bubbles of different sizes on the same sheet. Others use a shape that's different from the traditional circle such as a square or oval. Suction from inside the drum pulls the plastic sheet into each hole. This creates the different tops of the bubbles. Many manufacturers coat the first sheet with a type of material with a sticky property. This helps the two sheets stick together and offers a better way of protecting the finished product.

Finished Product

The manufacturer adds the other sheet of plastic to the top. The makeup of the plastic material causes the sheets to automatically attach to each other. This also causes air to become trapped inside each of the bubbles still inside the drum. The manufacturer then pulls the sheets off the drums and the bubble wrap is formed. The process from extruding to the drum is fairly quick, happening in less than a minute. The finished sheets of bubble wrap are typically very long and wide, which is difficult to sell. The manufacturer has to cut down each sheet by sending them through a cutting machine. This changes the sheets into more manageable sizes. Many send their sheets through a perforation sheet, which creates a series of small holes in different areas of the bubble wrap. This allows the sheets to tear off easily.