A consistent theme in the history of the industrial use of sheet steel concerns the ongoing reduction of sheet thickness. The advantages for all links of the value-added chain are obvious: increasing material efficiency is an immediate cost advantage while weight reduction slashes transport costs and environmental pollution as well as raising a company’s competitive edge.
These are considerations which have also led to an impressive innovation in the production of crown corks – the so called low- gauge crown corks. The standard sheet thickness for conventional crown corks has been between 0.22 and 0.24 millimeter to date. With the reduction of the steel thickness to 0.17 millimeter the new low-gauge crown corks are 0.07 mm thinner and 0.24 grams lighter. Considering the entire annual volume of 42 billion crown corks produced for one brewery alone (one of the biggest ones), these savings involved around 10,000 tons of steel or 10 million EUR. The development continues: first steps are done to reduce the sheet thickness to only 0,15 millimeter.
This is an impressive development. Nevertheless: similar to metal vacuum twist closures for preserving jars, the sheet thickness of crown corks can only be reduced with the aid of a special sealant compound. After all, the sealant is practically required to assume some of the steel's characteristics. And this is only possible using an extremely flexible and soft plastic. Actega DS met the challenge. With the of experience in handling thermoplastic elastomers and developing the most demanding formulae, a new sealant compound evolved during a two-year development phase in close collaboration with beverage and closure manufacturers. Meanwhile ready for market, free of PVC and plasticizers, a true innovation has been achieved in the form of the SVELON® 830 LG (Low Gauge) sealant compound supplied as granulate to closure manufacturers. The new sealant compound for lightweight crown corks displays similar properties to PROVALIN® the sealant compound free of PVC and phthalates for metal vacuum closures. The experience gleaned during complex development and testing of this sealant compound has made an enormous contribution toward SVELON® 830 LG which is also based on thermoplastic elastomers. A group of materials whose enormous flexibility and high degree of thermal and media resistance has displayed major advantages in processing and recycling in practically all areas when used as an alternative to vulcanized rubber, PVC and silicone. What's more, it also largely complies with the requirements concerning efficiency of resources and energy as well as safety and health for customers and consumers.
These themes will also be presented at the Interpack in Düsseldorf, May 8 - 14, 2014, Hall 11, Stand A 12.