PETpla.net Insider 10 / 2014

CAPPING / CLOSURES 36 PET planet insider Vol. 15 No. 10/14 www.petpla.net A special challenge or closure design and application Bottling of sensitive products Sensitive products can be bottled in an aseptic filling or hotfilling process. Aseptic filling of sensitive products If sensitive products like dairy products or juices are bottled in an aseptic filling process closures have to pass a washing process for decon- tamination of the closures. This wash- ing process takes off slip agent and changes the application properties of the closure. These changes must be counterbalanced by closure design. Bericap has developed a tamper evidence design which allows in the aseptic filling process easy applica- tion despite washed off slip agent and which allows rinsing of the tamper evi- dence band. The sealing design pro- vides a safe seal and does not worsen application. The screw cap range for aseptic filling is complemented with push-pull sportscaps which do not require an aluminium seal but pass the washing process safely and still offer an easy application. The predominant diameter in aseptic filling is 38mm. There exist a 3-start neck finish and a 2-start neck finish both having a good geographi- cal spread and preforms in the market with necks following these 2 stand- ards. The latest development is the move to a 33mm neck finish. The 33mm neck finish offers a substan- tial weight saving compared to a 38mm neck finish but still offers the necessary distinction on the shelf. In addition researches have shown that consumers appreciate the good comfort when drinking from a 33mm neck finish compared to other neck diameters. The 33mm neck finish rec- ommended by Bericap has a height of 15mm from top of neck to the support ring. This neck height provides safe application and at the same time good consumer convenience due to suf- ficient grip height. Hotfilling of sensitive products The alternative process to aseptic filling is hotfilling. The hotfill process remains a popular process since it is a safe process, less complex and requiring less attention of people running the filling line compared to aseptic filling. Closures and PET bottle necks used in a hotfill process are exposed to significant heat after capping and risk to get deformed when they become softened by filling tempera- tures around 80°C. Traditionally closures used in hotfilling are made from polypro- pylen and have an additional liner of resilient compound to achieve a good seal after the exposure to heat. These 2-piece closures require a high appli- cation torque resulting in high removal torque and have a risk of back-off. In addition 2-piece closures require PET necks with high wall thicknesses of 2,1 – 2,5mm in order to avoid neck deformation during exposure to heat. Bericap had developed the lin- erless DoubleSeal technology for carbonated beverages long ago. This technology is as of today state-of-the- art and has been successfully used globally in hundreds of billions. This technology does not rely on a top seal. It relies on an inner and outer