Styrene free polyester resin cartridges – a breakthrough technology for health and safety, with increased mechanical properties

Styrene is a key ingredient in polyester resin capsules, as commonly used within underground mining rock bolting applications. Over the last decade, there has been an increase in research and associated medical knowledge regarding styrene safety, particularly its health impacts upon people. For example, the issue of carcinogenicity and harmful effects on fertility and unborn children has been identified. Due to these health concerns, the use of styrene-based resin products in civil construction projects has been subsequently banned in Europe. This scenario has further raised safety concerns within resin cartridge production facilities, as well as in the handling and usage of cartridge resin at the end customer’s site.

In this paper, the characteristics and performance of a new generation of styrene free resin capsules is discussed. Among other relevant mechanical parameters, such as compressive strength and elastic modulus, stiffness properties in comparison with standard polyester resin capsules is discussed.

Finally, the paper also presents field validation tests conducted in underground mines in Finland and Spain. In these tests, the focus was set on resin capsule installation, its repeatability and productivity. New styrene-free capsules have been positively tested on commonly used bolting rigs, for instance, the Sandvik ARI (Automatic Resin Injection) system. Laboratory and field data that has been compiled throughout product validation activities has confirmed the improved mechanical performance of the new styrene-free resin capsule technology and verifies its routine use for rock bolting applications in underground mines.