Mako Advanced Materials, a US-based developer and manufacturer of advanced composite solutions, has launched a new creel-free unidirectional (UD) carbon fibre prepreg combining aligned carbon fibre reinforcement with the company’s proprietary HyperCure epoxy resin system. The material is designed for applications in aerospace and defence, space, motorsports, marine, medical and sporting goods.
Unlike woven reinforcements, UD materials align all fibres in a single direction, allowing engineers to orient individual plies according to the main load paths of a component. This can provide high stiffness and strength in the fibre direction while limiting fibre crimp and helping optimise laminate weight.
Standard production requires the installation of a large-scale creel system — an industrial rack or frame that holds multiple spools of fibre and allows them to be unwound simultaneously in a controlled manner –, which entails a significant footprint and considerable processing time. Due to these substantial installation requirements, traditional suppliers impose high minimum order quantities and extended lead times. They are also less inclined to accommodate requests for custom grammages, alternative fibres or specialised resin formulations.
Cover photo: Mako UD prepregs application: The International Space Station’s Canadarm 2 is preparing to release the Orbital (source: Mako)
Greater flexibility made possible
With its creel-free process, Mako starts with carbon fibres that are already aligned and stabilised for coating, eliminating the large creel setup traditionally required for UD prepreg production. According to the company, this approach enables smaller batch sizes, lower minimum order quantities and shorter lead times, while making it easier to accommodate different fibres, areal weights and resin formulations.
The prepregs are available with standard-modulus T700 and intermediate-modulus T800 carbon fibres, with high-modulus options offered in certain configurations. Areal weights start at 55 g/m², while stitched UD configurations combining several plies are available from 250 g/m². Custom widths and areal weights can also be specified.
When combined with Mako’s HyperCure epoxy resin system, the UD prepreg can achieve complete cure cycles in approximately nine to ten minutes, depending on laminate thickness. It can also cure at the same rate as HyperCure woven prepregs used within the same laminate, simplifying the manufacture of structures combining UD and woven reinforcements. The resin retains an outlife of 30 days at room temperature and can be processed using both lower-temperature prototype cures and higher-temperature rapid production cycles.
Mako particularly highlights aerospace and space applications, where the ability to produce small quantities of customised UD prepreg can support prototyping and initial production before volumes increase. The company also points to shorter cure cycles as a means of increasing production throughput and reducing the energy required to manufacture each composite part.
