PETpla.net Insider 04/ 2013

CAPPING / CLOSURES 34 PET planet insider Vol. 14 No. 04/13 www.petpla.net Caps and closures for sensitive soft drinks – the Corvaglia approach* Sense and sensitivity *based on an article by Dr. Michael Krueger, CTO Corvaglia Group The risk of contamination is especially critical for sensitive beverages. As a company specialising in providing tech- nologies for soft drink closure solutions, Corvaglia’s primary goal has to be to avoid penetration of particles or other foreign matter into the bottle under any conditions. In this article Corvaglia presents its approach of taking all types of effects into consideration in the cap/closure design. Effects of pre-treatments Sensitive beverages can be affected and contaminated by external influences like light, temperature, oxygen or micro-organisms to name only a few. It is quite clear that by far the most amount of light or heat will enter through the bottle and not through the closure. Sensitive drinks are usually pre-treated and/or bottled using a filling method that either cre- ates or maintains the sterility of the bottle’s contents in order to increase the shelf-life of the drinks by killing potential micro-organisms. Both pre- treatments and filling procedures have an impact on the performance of the package. Hence the package design has to take these effects into account. Table 1 summarises some of the types of treatment typically used prior to fill- ing to sterilise or clean beverages. Effect of filling methods Similarly, filling processes can create exactly the same challenges as pre-treatments since the same meth- ods of sterilisation are used for both (c.f. Table 2). Obviously, challenges can vary significantly for the same treatment or filling types depend- ing on implementation. For instance, whether an aseptic cold filling is done ‘dry’ or ‘wet’, dipped into a bath or sprayed on the product can make a difference: for dry aseptic procedures where hydrogen peroxide steam is used for sterilisation, the temperature of the closures can still be as high as 45°C when arriving at the chuck. This changes elasticity and consequently its capping behaviour. Using wet aseptic procedures, closures arrive at Temperature Radiation Filtration Pressure Chemicals Pasteurization Magnetic pul- sation 5μ, 1μ, 0.2μ UHP Ozonation UHT UV Reverse osmosis Sulfuration Electron beam GAC Preserving agents Ultrasonic pasteurization Multimedia filtration Electron beam Table 1: Examples of types of treatment that can be used prior to filling in order to sterilise or clean beverages. UHT = Ultra high temparature; UHP = Ultra high pres- sure; UV = Ultraviolet radiation; GAC = Granular activated carbon. Temperature Radiation Filtration Pressure Chemicals Hot fill Plasma - - Addition of pre- servatives (e.g. E242 ‘Velcorin’) Tunnel pas- teurization UV Aseptic cold fill Table 2: Examples of filling processes that can be used to sterilise beverages or maintain sterility. UV = Ultraviolet radiation Temperature Radiation Filtration Pressure Chemicals Change of material prop- erties Change of inherent mate- rial properties - - Change of organo- leptic properties Change of shapes of packages Remains of treat- ment chemicals Table 3: Potential hazards associated with pre-treatment types and filling proce- dures that have to be accounted for when designing closures the capping chuck with a lower tem- perature. Effects of temperature and chemical treatments When designing a package or clo- sure, the effects of temperature and chemical treatments must be primarily taken into account. The former can for instance change the sealing perfor- mance by changing the material prop- erties. The risk associated with the A Corvaglia 33mm hotfill closure on a sport drink