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Send to KindleNo-label look hits PET bottles
While esthetics was the primary driver behind the remake of the package there were performance issues as well paneling or collapse of the bottle's sidewall in particular. The likelihood of this occurring increased as distribution distances grew. Another factor in the materials change was increasing penetration of the Japanese market well known as a zero-defect zone.
Brzeski points to two mechanisms that caused the paneling problems. First the bottle sidewalls were sometimes weakened by certain product components that adsorbed into the molecular chains of the HDPE. PET's structure is inherently more impervious to such penetration.
The other cause of paneling was absorption of headspace oxygen by the product. This created an internal vacuum sufficient to cause paneling. But the PET bottle thanks partly to sidewall structural strength imparted by orientation is better suited to withstand such pressure.
Wall thickness of the new bottles was carefully considered says Brzeski. "We wanted good squeezability for all products regardless of viscosity" he points out. "So we had to select a wall thickness in the middle if you like."
Ultimately the bottles were specified with the following weights and wall thicknesses:
* 2-oz: 8 g and .40 mm
* 4-oz: 12 g and .45 mm
* 8-oz: 21 g and .43 mm
* 16-oz: 35 g and .45 mm
Two features of the custom PET bottle are worth singling out. One is the string of dots molded into the bottle at the shoulder. As in the past The Body Shop encourages customers to bring the bottles back for refills and this mark tells shop personnel how high they should fill the bottle.
The other unusual feature is the etched surface of the bottle. "It's not done with a spray or by means of adding something to the master batch which could affect the bottle's recyclability" says Brzeski. "It's actually done in the mold." While the bottle is still clear the etching gives it a subtle point of differentiation from other health and beauty products in PET containers.
'Quantum leap'
Though typically a bottle made of PET would cost considerably more than one of HDPE The Body Shop was able to keep packaging costs in line. Brzeski explains how.
"We joined forces with The Body Shop in Canada which used to order its bottles independently of us" says Brzeski. "This represented a quantum leap in volume." That in turn brought savings due to economies of scale. "Also" adds Brzeski "the tooling used to produce PET bottles is higher in cavitation than with HDPE and that helps keep unit pricing in line as well."
Overall the company estimates the new packaging costs about 10% more. Part of that is the difference between stock and custom closures. Labels are more expensive too. Formerly printed on a letterpress system they now combine screen printing and letterpress.
"Also adding to the label cost is that we used to order one size label for all four bottle sizes" says Brzeski. "We then imprinted the declared fill on the label as the bottle went through the packaging line. Now we need a different label for each size largely because the bar code is unique for each."
The upcharge associated with the new packaging is justified by the benefits gained says Brzeski.
"By eliminating the paneling problem we're able to deliver a higher quality package to the consumer" says Brzeski. "In addition we now have on our label a bar code that helps in sales analysis and point-of-sale information. Finally the disc-style closure is clearly preferred by today's consumers."
Considering The Body Shop's track record on the environmental front it's no surprise that the next phase of the package revamp is the inclusion of post-consumer PET in its bottles. According to Brzeski Wellman was selected as resin supplier partly because of its experience in supplying RPET.
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