How is Bubble Wrap® packaging made?
Bubble Wrap® brand cushioning starts as polyethylene (plastic) resin, in the form of beads about the size of small peas. The beads go into an extruder – a long cylinder with a screw inside that runs its entire length. As the screw is turned, heat builds up and the resin melts into a liquid that is squeezed out of the cylinder into two stacked sheets of clear plastic film. One layer of the film is wrapped around a drum with holes punched in it, and suction is applied drawing one web of film into the holes that form the bubbles. The second layer of film is then laminated over the first so that when the two films are joined, they stick together and trap the air in the bubbles. This may sound easy, but polyethylene is a porous material like a sponge. Air can easily leak out through the pores, which tends to limit the cushioning ability of the packaging. Realizing this, Sealed Air started using a Saran coating to seal the air in the bubbles. Eventually, a method of encapsulating an air rete
