The launch of bio-based caps for gable top cartons comes as Tetra Pak reports an 80% increase on delivery of bio-caps in 2013, with 1.1bn delivered globally.
Christina Chester, product director, Tetra Pak, told DairyReporter.com its first bio-based cap was released in 2011 (the StreamCap1000 for 1L square cartons), and is being rolled out to other products.
Sugar cane
“This is the first time anyone has used a bio-based cap on gable top packaging," she said. "We’re rolling it out bit by bit across out product range, where we have customers interested in it.”
Gable top cartons have a roof-shaped lid, which forms a spout when pushed open, and are commonly used for milk and fruit juice. The bio-based cap design is made from high density polyethylene (HDPE), which is derived from sugar cane.
80% of the material in a 1L Tetra Rex gable top carton is paperboard, which is made from wood, a renewable resource.
By introducing a bio-based cap, the renewable material in the package increases by 4%. This improves the environmental performance of the package without affecting its functionality or recyclability, the company claims.
What's next for renewable packaging?
The next step is to address the material used for the inner and outer plastic protective layers of the carton.
“The ambition of Tetra Pak is to reach a fully renewable package in the future,” said Chester. “What remains is the protective layer, which is not made from renewable materials. We’re working hard to find renewable sources for these plastic layers that are sustainable.”
The layers are currently made from normal (not sugar cane) polyethylene.
Tetra Pak customers using the standard TwistCap OSO 34 for gable tops can transfer to the bio-based version without changing their existing filling machines.
“Launches of bio-based caps have been appreciated by customers like Valio, the Finnish dairy who is the first to use the new version of TwistCap OSO 34 for its products,” said Chester.
The renewable polyethylene used in the cap is made from sugar cane.
The cane is crushed and the resulting juice fermented and distilled to produce ethanol. Through a process of dehydration, this ethanol is converted into ethylene, which is polymerised to produce polyethylene.
This polyethylene is used to manufacture a number of Tetra Pak bio-cap designs.
Packaging giant Tetra Pak supplies hundreds of different types of carton packaging and has its headquarters in Switzerland.