CST guides Kimberly Clark to composites conversion

CST Composites in Australia has developed four carbon fiber spindles for Kimberly Clark that replaced heavier, more dangerous steel spindles.

Sydney, Australia-based filament winder CST Composites says it has recently supplied Kimberly Clark's Australian Baby Care division with four carbon fiber unwind spindles. Kimberly Clark's engineers approached CST to find an alternative to traditional steel spindles in order to save weight and improve operational health and safety in their factory. The spindles are used to support a large paper roll, which is unwound during the manufacture of diapers. The 850-kg rolls are frequently changed, requiring regular manual handling of the spindles. By reducing their weight the risk of personal injury is significantly reduced and shaft changes can be made more efficiently thus improving factory output.

CST worked with Kimberly Clark to develop an optimized carbon epoxy shaft capable of meeting the loading and handling requirements. The new carbon fiber spindles were filament wound at CST to give a tough yet stiff and strong tube section. Following winding the carbon tubes were post-cured at high temperature before being fitted with end plugs and stainless steel collars to help protect against general operational wear and tear.

In accordance with Kimberly Clark's operating procedures the completed spindles were load-tested by an independent NATA approved laboratory. During the test the carbon fiber spindles successfully supported more than 1700-kg, twice the maximum working load specified by Kimberly Clark's engineers.

The 900-mm-long composite spindle with end plugs and stainless steel collars weighs 3.6 kg, more than 4 kg less than the basic steel shaft. With changes to the nylon support ring design the complete filament-wound carbon spindle assemblies weigh just 5 kg compared with 14 kg for their steel counterparts. The spindles are currently under evaluation at Kimberly Clark, following which both companies hope to substitute further carbon shafts into the production line.