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 FibreLINE a unique product in the global market, including the pioneering layup tools of FibreFORM and FibreROLL at the system’s core. Later articles will delve into the other stages in the preforming process and composite automation including material cutting and kitting, as well as inspection, tacking and consolidation and the end effectors that accomplish them.
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).
Challenges in Composites: Carbon Fibre and Other Material
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. 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 isn’t sufficient to meet up with the production demand in certain industries, such as aerospace. The machines require significant investment and factory space with high energy costs.
End-to-End Automation for Composite Preforming
Loop Technology’s FibreLINE stands out 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 very large plies of carbon fibre and other composite material, placing them into the designated mold in record time. 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). FibreLINE offers vast opportunities to drive efficiency into the downstream assembly process when compared with other state-of-the-art automation methods such as AFP. By delivering high rate preforming and a radical increase in composite material deposition rates into just one set of mold tools with one set of tolerances, it significantly reduces complexity and time compared to AFP processes that need to use multiple mold tools with resulting combinations of tolerances, in order to achieve a comparable rate. FibreLINE means less shimming and assembly processes, ultimately saving time and resource for the manufacturer in this regard.
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 mold, 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. As a result, the laminate is made in record time. 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 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 solution where the entire preform process is situated on one factory floor, with less outsourcing and a significant reduction in logistical complexity.