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STYRENE-butadiene (SB) block copolymers are a relatively new and innovative field in which a number of developments have recently been marketed. At the same time, BASF is celebrating two anniversaries in this field: 20 years of Styrolux and 15 years of Styroflex.
The SB block copolymer, Styrolux, was first produced on a commercial scale 30 years ago in Germany. Ten years later, a second production facility was built in Antwerp and, in 2004, an additional production facility was added in Mexico. Today, BASF has a production capacity of 110 000 tons/annum. Styrolux, an SB block copolymer, stands out for its transparency, durability and rigidity, which is ascribed to the material’s capacity to self-organise on the molecular level.
It can be blended well with standard polystyrene and is easy to process – primarily it’s extruded into films and deep-drawn to create many different parts, although it can also be employed in injection moulding. One of the most recent variants is Styrolux 3G46, a highly-transparent material found in high-end display packaging, while Styrolux HS 70, the latest product, was developed especially for the production of shrink film.
Shrink film, made of the HS 70 grade, returns virtually to its initial shape, even after being stretched to six times its original size under exposure to heat. Consequently, films made of this material are particularly well-suited for shrink wrapping bottles and other containers with a wide array of shapes. A special variant from this product family, the thermoplastic elastomer (TPE) Styroflex, was launched 15 years ago. This material differs from the classic SB block
copolymers in that it combines transparency, high elasticity and processing stability.
Styroflex has recently made its way into the manufacture of stretch hoods and, even after being stretched by 220%, a composite packaging film with a thin central Styroflex layer clings to packaged items, holding them securely on the pallet.
Originally developed as an alternative to soft PVC, Styroflex is now being employed in numerous fields. Transparent meat packaging is often made of stretch or cling film containing TPE. As a toughness modifier, it improves the application properties of HIPS (highimpact polystyrene), an impact-resistant polystyrene,
and ABS.
Lightweight, sturdy EuroPallets
Whenever bulk goods are transported they are usually consolidated on pallets for easier handling –
traditionally made from wood. Now, a new generation of plastic transport pallets is being launched onto the
market by the Hirsch Group in Austria. These pallets overcome many drawbacks of the conventional models, including being easier to clean, sturdy and more lightweight than those made of wood. The highly-elastic BASF styrene-butadiene copolymer Styroflex 2G66 is crucial in this innovation
- Packaging & Print Media