<\/p>\n
Single use PET bottles are a high profile target of sustainability and source reduction\u00a0efforts. Major producers are keenly focused on reducing packaging throughout the process, and specifically addressing the bottles themselves.<\/p>\n
For example, in a recent interview<\/a> Nelson Switzer,\u00a0Vice President and Chief Sustainability Officer for Nestl\u00e9 Waters NA, provided some statistics:<\/p>\n These are impressive changes. And they’re the result of process improvements enabled by improving materials and machines.<\/p>\n What’s interesting is that each step along the way has changed the demands on the stretch wrapping\u00a0equipment<\/a>, and the evolution provides a good case study for how changes in up stream packaging needs to be accounted for in the stretch wrapping process<\/a>.<\/p>\n One of the first reduction approaches was an obvious one. Replacing corrugated with film.<\/p>\n There was a time when bottled water was packaged in full corrugated cases. Gradually those were replaced with corrugated trays and shrink bundling with polyethylene film. An “8 corner” tray design\u00a0introduced\u00a0in the 90s eliminated the sharp corrugated corners which had tended to tear the shrink bundling (or shrink wrap) film. Essentially it cut off the corners and created a shape which matched the round profile of bottles in the corners of the pack pattern.<\/p>\n Replacing corrugated with shrink film eliminated a substantial portion of the case packaging volume – but it wasn’t without consequence. The stacking strength<\/a> which the corrugated cases provided (which remarkably can be reduced by 30% if cases simply aren’t square<\/a>) was now eliminated – and at a pound\/pint the weight of a load of water is a significant factor. Stacking strength isn’t a trivial concern! Now the entire stacking strength burden fell to the bottles themselves.<\/p>\n And that was problematic, because\u00a0around the same time the corrugated\u00a0cases were cut down to trays, efforts began to reduce the wall thickness of bottles – which of course further reduced the\u00a0stacking strength.<\/p>\n\n
Cutting the corrugated down to (tray) size<\/h2>\n
Drawing down the bottle walls<\/h2>\n