Beverage industry seeks savings through short-neck closures

Targeting this opportunity, Borouge (Singapore) recently developed two high stress crack resistance HDPE grades for caps and closures. "These grades may make their mark in particular in Southeast Asia and China, where summer temperature are high," notes Wim Roels, CEO of Borouge. "They would enable the use of short-neck closures in carbonated beverage packaging."

"The HDPE material also enables design of a one-piece cap as it is flexible enough to ensure a good seal. PP caps, conversely, require use of an elastomeric seal in a two-piece design," adds Roels. Short-neck caps also present challenges in ensuring that they are easy to open even for children and the aged. "You need a low enough torque for opening, as well as that reassuring opening sound," explains Roels.

Italian compression molding machine manufacturer Sacmi (Imola) was using one of the Borouge grades to mold caps at the rate of 2,000 per minute in a 48-cavity machine at the Chinaplas show in Shanghai last May. Closure diameter was 29 mm and weight was 1.35 grams.

The grades in question, BorPure MB5568 and MB5569 are designed mainly for caps and closures for carbonated soft drinks, juices, tea and bottled water. Built on the Borstar multimodal polyethylene (PE) technology platform, they are said to deliver an average 50% and 10% improvement, respectively, in stiffness and environmental stress crack resistance (ESCR) over their predecessors BorPure MB6561 and MB6562.

 "The beverage industry is constantly looking for solutions that improve cost efficiency," commented Aster Teo, Borouge's Application Marketing Manager for Caps and Closures. "Brand owners and converters have been focusing on reducing the weight of closures. As such, BorPure MB5568 and MB5569 will support this initiative and enable the value chain to meet this goal."

 While lightweighting has been a priority, taste and odor of the product is of primary importance to the consumer. BorPure MB5568 and MB5569 also reportedly provide the industry leading organoleptic properties to ensure that the taste and odor of the product are not altered. When it comes to ease of processing, as a multimodal polymer, BorPure MB5568 and MB5569 have a flow equivalent to that of benchmark unimodal MFR 2 HDPE resin.

 "With BorPure MB5568 and MB5569, converters and brand owners can produce lighter closures and be cost competitive," added James Ong, Borouge's Marketing Manager of Marketing Centre Moulding. "In doing so, they also reduce the carbon footprint of their products and consequently contributing to environmental sustainability."