Coperion GmbH, Stuttgart, Germany, announced in June it successfully defended the European patent protecting the 5A kneading blocks it uses with its ZSK series twin-screw extruder. The ruling by the Board of Appeals came after another company had challenged the patent.
Since registering the patent in 2003, Coperion has primarily used the kneading blocks in large machines to prevent damage, such as cracked shafts or coupling malfunctions, that could be caused by vibration. According to the company's website, its standard kneading blocks are made of nitrided steel, though other, more wear- and corrosion-resistant materials are available as an option.
