Consumers can get very, very attached to the packaging of their favorite products, and nowhere as intensely as beverages. Trifle with the material, color or label at your own risk, marketing experts say.
So when the makers of Snapple decided to move to plastic bottles from glass, there was tremendous trepidation at Dr. Pepper Snapple Group headquarters in Plano, TX.
So they started from scratch. Company execs wanted to design a plastic bottle that simulated the look, heft and even sound of the original glass bottle, but at less cost. The only element of the new packaging that the company wanted to remain the same was the metal cap; they feared a plastic cap wouldn’t literally have the same “pop” as the metal cap does when it is opened.
To migrate from glass to Polyethylene terephthalate (PET) for Snapple wasn’t easy, technically speaking. Perhaps the most important challenge was ensuring the plastic bottle looked as much like glass as possible. But that meant no side panels, which are typically used to absorb the vacuum produced during the hot-fill. But creating a vacuum was still necessary because that’s what makes the metal cap “pop” when it’s opened.
The answer? Create a plastic bottle with an uncommonly thick wall of 0.038 inches. But the sheer weight of the bottle presented other problems, chiefly molding and reheating a preform so it wouldn’t take to long to make the bottle. Another challenge was maintaining wall thickness: if the thickness varied, the wall would collapse and not contain enough vacuum to suck down the metal cap. And heavy walls have lower stretch ratios, which exacerbates the “vacuum-creating” problem.
Next came the challenge of instituting a consistent and precise fill level: if the bottle was filled too high, for example, the finish would begin to deform, reducing the removal torque level.
Next issue: the cap — it needed to be redesigned to work with the plastic finish. More on that in a future blog post.