Automating Composites: How FibreLINE Differs From Any Other Method
Following on from the first article in this series, where we summarised a few of the wide range of different composite manufacturing methods across the industry, we will now explore some of the primary reasons that make Loop Technology’s FibreLINE a unique product in the global market, including the pioneering layup tools of FibreFORM and FibreROLL at the system’s core.
A significant limiting factor in achieving ultra high rate composite aerostructure manufacturing and meeting the increased demand efficiently is the preforming technology. FibreLINE is revolutionary new approach- a fundamental categorical shift in the approach to preforming, that provides a much more efficient way to manufacture composites.
One FibreLINE system achieves material deposition rates in excess of 200 kg per hour where the other automated approach, in AFP/ATP, reaches 20-50 kg per hour. Thus, multiple AFP/ATP machines need to be used to match the FibreLINE rate, requiring much greater factory space, consuming more energy and resource. Additionally, multiple machines of this kind mean multiple mould tools and resulting sets of tolerances which leads to more shimming tasks and greater complexity in downstream assembly. Manual composite layup has comparably low rates of production and variable quality. FibreLINE is the most economically compelling and viable route to meet this demand for next generation aerostructures.
Challenges in Composites: Carbon Fibre and Other Material
There are many factors and variables that engineers consider when choosing their approach to manufacturing composite structures. They assess the exact shape of the final part and what the appropriate method is to layup into mold. They also select the type of reinforcement material- for instance carbon fibre, fibreglass or aramid – the resin, and the form the material will come in such as dry fibre or pre-preg. There are numerous considerations across each domain and subdomain of the process. For instance, in the fibre selection, will it be woven, non-crimp, unidirectional, chopped, mat or braided. Will the matrix selection be a thermoset polymer (epoxy, polyester, vinyl ester) or thermoplastic polymer (PEEK, polypropylene, nylon).
Despite the wide variety of approaches and materials available, there are often challenges and limitations. For instance, traditional composite manufacturing methods are limited by access to skilled labour, variable quality and relatively low rates. Manually handling dry fibre can lead to the material fraying, distorting or getting misaligned during layup. Using pre-preg material can be challenging due to its tackiness making repositioning difficult, whilst the material itself has specific storage requirements and a limited shelf life. As previously mentioned, the alternative automated solutions such as Automated Fibre Placement (AFP), that tend to use pre-preg material, are limited to 20-50 kg material deposition rates, which mean multiple machines and significant investment to achieve the manufacturing rates that the aerospace industry demands.
End-to-End Automation for Composite Preforming
Loop Technology’s FibreLINE stands out as well because it offers a way to automate the preforming process for the manufacture of a wide range of different sized and shaped composite structures. It does so at a rate beyond any other, handling both dry fibre and pre-preg material. It is reconfigurable, and scalable (FibreLINE 2×1 for smaller composite parts) across a multitude of different applications and able to fit into a range of industrial processes, unlike many automation solutions that are monolithic and cannot be repurposed. The tolerances and speed that FibreLINE offer ultimately moves the composite industry closer to where it wants to go: aerospace grade accuracy in layup, but at a much faster production rate nearer to the automotive industry.
High Rate Layup on a New Scale
At the core of FibreLINE, are two innovative end effectors, FibreFORM and FibreROLL. Both can layup extremely large plies of carbon fibre and other composite material and place them into the designated mould with aerospace grade level accuracy. By bringing together such large multi layer plies so quickly and precisely, FibreLINE dramatically reduces the number of pieces needed to make a composite part or component (for example taking an aircraft wing down from 150,000 pieces to c.150).
FibreFORM uses high flow vacuum generator grippers that can form the composite sheets into a wide range of shapes including concave, convex and omega double curvature profiles modelled with 5th order polynomials. It does this, where necessary, to match the highly complex geometric surfaces of the mould, placing the ply precisely on the surface without damaging the material. FibreFORM is unique in this regard – no other comparable automated gripper system can pick such large plies off a cutting table or kitting storage system and manipulate them into extremely complex 3D shapes for a single piece layup onto the matching complex mold shape. Traditional manual layup is unable handle such large pieces in such a delicate and precise way. FibreFORM can achieve a material deposition rate of 200 kg per hour and beyond, alongside a positional repeatability of ± 2mm. It can pick, form and place plies beyond 30 metres if necessary. The laminate is made in record time and there is no need for realignment, readjustment or replacement of material damaged during the layup process.
FibreROLL is an automation system that uses interchangeable storage rollers, to pick and place plies up to 5 metres wide and 20 metres long, with a relatively small footprint. FibreROLL has a core roller which can be used as a storage solution for large dry fibre rolls and the system can also be fitted with integrated tacking. It is applicable for layup onto tools with less complex geometric surfaces and can be used in the manufacture of wind turbine blades in the renewable energy industry and for spars and sections of the fuselage in aerospace. Recently achieving a material deposition rate in excess of 350 kg per hour in breakthrough trials, there is no other comparable system in the world that can achieve this rate.
Reduced Factory Footprint and Step Change in Production Rate
FibreLINE is a complete automation system for ultra high rate composite preforming, delivering a step change for the industry by being able to layup amounts of material in 35 seconds that it would take traditional techniques 2 hours to do. The system occupies significantly less factory space and consumes less energy than comparable state of the art methods. This reduction in factory footprint and its end-to-end functionality, offers composite manufacturers a integrated equipment solution where the entire preform process is simplified and more efficient.