Tetra Pak makes materials change for liquids packaging

Food and beverage packaging processor Tetra Pak (Lund, Sweden) is changing the materials it uses for its composite paperboard/plastics/aluminum foil containers in a global move it says will reduce reliance on polymers by selecting a tougher, stronger resin.

The new standard packaging material, brand-named Wide, for roll-fed chilled-liquid beverages, consists of an inner extrusion-coated layer of metallocene-based linear low-density polyethylene (mLLDPE) that Tetra Pak''s Jörgen Haglind says is 30% thinner than the previous low-density polyethylene coating and requires less resin for the same effect. He says Tetra Pak will be able to reduce its global consumption of polymers, primarily polyethylene, by 50,000 tonnes/yr. At the same time the company is increasing the use of recycled paperboard in the packaging by 3.5%, according to Günther Lanzinger, project director.

"We have already produced more than 50 billion packages around the globe [using Wide] with Australia, Brazil, and Japan leading the way," he says, "and both manufacturers and retailers are reporting better product performance and more cost-efficient operations." By March, the new packaging material will be the de facto standard for carton packages from Tetra Pak.

A current Tetra Brik aseptic carton is typically made of 77% paperboard for strength, 18% LDPE to provide moisture barrier and sealability, and 5% aluminum foil, generally 6.35 µm thick, for odor, UV light, and gas barrier. Such packaging can consist of up to seven layers with a LDPE outer layer for moisture and dirt protection that covers the printing ink layer applied onto the paperboard. This is followed by a tie layer on each side of the aluminum foil and finally another extrusion-coated LDPE layer for sealing. It is this last layer in the Wide concept, which is being replaced with the mPE.

Haglind says the mPE resin requires 17% less energy to process. It also makes the overall package lighter. "We achieve even better sealing properties leading to an improved package integrity," he says. "[The cartons] become generally more robust to cope with outer stress such as stackability or mistreatment in distribution." Tetra Pak has not revealed its polymer supplier.-Robert Colvin; [email protected]