Better drying saves Nestlé Waters more than $1 million

This month, we take a drink of Best Practices knowledge from the ubiquitous PET water bottle. Consumers take them for granted, but they are a miracle of technology, downsized nearly to the point of being a “bag of water” as machinery manufacturers and consumer products companies have waged a relentless effort to reduce the amount of resin used.

Behind the scenes, a high-volume PET bottle factory uses a lot of energy, for drying the massive amounts of material needed for preforms, and to blow mold the containers; for chilled water to cool the molds and compressed air for forming all those bottles.

Drying is especially critical. PET is a hygroscopic resin, meaning that it absorbs water. Improperly dried PET can cause defects in preforms and bottles.

And so is heating, since the injection molded preforms have to be heated up before they can be blow molded. That’s the subject of this month’s Best Practices report.

In a beverage bottling operation, officials of machinery maker Sidel Group and Nestlé Waters were already well aware the blow molding machines generally account for as much as 70 percent of the total energy consumption of a complete bottling line, according to a case study released by Sidel.

Sidel is the blow molding equipment unit of Tetra Laval Group.

Nestlé Waters and Sidel worked together to cut energy use by more than 1 million euros a year ($ 1.12 million) — equal to more than 20 ovens in the blow molding machines.

Nestlé Waters launched its energy conservation program in 2010, when it challenged Sidel to rationalize energy consumption for all of its production equipment. Nestlé is a huge player in bottled water, with more than 96 production facilities in 35 countries.

For a company like Nestlé Waters, cutting energy improves its environmental performance — boosting the “green” credentials of plastic water bottles as they face criticism by environmentalists — and keeping the company’s operating costs to an absolute minimum. That’s the “green” as in money saved.

Sidel has a 50-year relationship with the brands of Nestlé Waters.

When Sidel leaders got the word that Nestlé Waters wanted to reduce energy use, the machinery manufacturer started out by conducting one of the company’s eco audits on two of the blow molding machines at the bottled water giant. Then Sidel identified some recommendations.

One major one: Install oven-top reflector lamps to maintain energy in the ovens that heat PET preforms in the blow molding presses. According to the Sidel case study, that change resulted in a reduction in electrical power required for preform heating equivalent to turning off 20 perform ovens.

Stephane Bosshart, Nestlé Waters’ corporate chief engineer, said that based on the good results of up to 20 percent energy savings from the two test machines, the company decided to implement a full eco-program, sharing those best practices with all of its blow molding machines around the world.

By the end of 2015, nearly 130 Sidel blow molding machines were converted with the oven-top reflector lamps. The return on investment? Between six and 24 months.