As the automotive industry accelerates towards decarbonisation and electrification targets, the need to boost efficiency in part production has become increasingly urgent. Manufacturers face the challenge of how to produce thousands of composite parts each month reliably, repeatably, and cost-effectively, while at the same time controlling the way they are managed and monitored to comply with industry standards.

One of the most significant challenges facing the composites industry is how to manufacture materials and parts at rates that will make them useful to high-volume industries such as automotive, leisure and marine. While manufacturers recognise the benefits of composites in these markets, there is still work to be done to make them a viable solution on a major scale. Manufacturing at rate

Manufacturing at rate

In 2021, Cygnet Texkimp became part of a collaboration to develop the technical and supply chain capability to achieve high-grade, composite-intensive parts at rate for high-volume markets. The
ASCEND programme is a four-year
UK partnership led by Tier-1 aerospace supplier GKN Aerospace, with funding from the ATI Programme, a partnership between the Department for Business and Trade, Innovate UK and the Aerospace Technology Institute. As part of the programme, the company developed several pieces of technology to address the need for high-rate manufacturing of composite parts. These include the short-footprint, energy-efficient Multi Roll Stack prepreg processing solution, which is designed to deliver more sustainable, lower-cost thermoset prepreg and towpreg materials. Most recently, a fully-automated, five-axis filament winding cell capable of manufacturing, handling and processing CNG and hydrogen tanks cost-effectively at rate was also developed. The challenge in
building the automated cell was to develop a system that could not only manufacture complex filament-wound parts effectively but do so in large volumes too. Crucially, this focus on volume requires effective management of the process. In addition to reducing the time it takes to wind complex composite parts, the objective was to make them viable in the market by developing bespoke systems to automate every stage of the process. The automation solution developed around Cygnet Texkimp’s filament winding technology means each component can be efficiently
handled through the process, while critical data, including weight, size, fibre tension and resin-fibre ratio, are systematically gathered and recorded.

Winding capability

The multi-spindle winder is capable of processing many types of materials from slit tapes and towpregs to dry fibres combined with an in-line resin wet-out system. The automated demonstrator cell, which is housed at Cygnet Texkimp’s UK innovation centre, can manufacture tanks measuring 3 m long and 0.5 m in diameter, but the technology is entirely scalable. for each tank. The length and diameter of the liner and the wound tank, and the total length of fibre unwound from the creel into the process, can also be measured and
plotted in the same way. This provides confirmation that the correct amount of fibre and resin has been used to manufacture the tank and offers a valuable process check. The tension of the fibre as it enters the winding process can also be measured, along with the temperature of the resin wet-out system, the amount of resin in the system, the hardener-to-resin ratio, and the level of inflation and pressure within the tank. Equipped with these measurements, the manufacturer is able to manage the balance between weight and strength and build the most accurate record of the tank. This allows the exact details of the tank’s manufacture to be traced back to the process in the future and used to identify trends, change recipes, and develop the process further. The data also facilitates recycling of the composite part at the end of its life. To begin with, the focus is on the manufacture of tanks for the commercial automotive and aerospace sectors. But the cell also
demonstrates the capability to produce hydrogen vessels for high-volume, mainstream automotive where demand is expected to reach millions of units each year by 2040.

AGV technology

A robot-mounted compact automated guided vehicle (AGV) was used to perform multiple tasks in the cell (Figure 1). These include loading and unloading packages of fibre or tapes on and off the driven creel that feeds them at tension into the winding process, and manoeuvring tank liners and wound tanks weighing as much as 300 kg quickly and easily through the process, to eliminate manual handling and improve processing speeds. The robot is mounted onto an omni-directional AGV fitted with drive wheels that can rotate 360° and allow it to navigate in any direction. Unlike
transfer cars, which run along rails, the AGV can run anywhere it is programmed to, an is ideal for use in factories with restricted floor space. The system can be programmed to follow a pre-determined route and easily re-programmed to accommodate layout or task changes, or controlled manually via a joystick. Multiple AGVs can be incorporated into a single system, depending on the volume of tanks being produced, and fitted with traffic management technologies, including laser scanners and encoders, to ensure people and machinery can work safely alongside each other. To maximise productivity, the AGV is programmed to perform tasks without having to pause the winding process. This capability is enhanced by an automatic or semi-automatic tie-on, tie-off solution. It is used to cut the fibres feeding the finished tank and hold them in place, ready to wind a new tank, with no or limited operator assistance required. The AGV removes the wound vessels from the process and replaces them with new vessel liners ready for winding. The wound vessels are then transported to an oven for curing, and onwards into other downstream processes.
Highest rates of production are achieved by increasing the number of spindles simultaneously winding tanks. Each servo-driven spindle represents a single vessel. The machine can be scaled to
incorporate 2, 4, 6, 8 or more spindles.

Data management

With high numbers of essential components being manufactured, part of the company’s role was to design a way to capture and record unique data about each one. To achieve this, an inspection
protocol was built into the process that complies with the industry’s assessment and documentation standards.An integrated weighing mechanism positioned at each end of the spindle delivers an important set of data for each tank. It is used to weigh the tank liner before winding begins and the wound tank at the end of the winding process and again after curing, with results recorded in a unique data tag. for each tank. The length and diameter of the liner and the wound tank, and the total length of fibre unwound from the creel into the process, can also be measured and plotted in the same way. This provides confirmation that the correct amount of fibre and resin has been used to manufacture the tank and offers a valuable process check. The tension of the fibre as it enters the winding process can also be measured, along with the temperature of the resin wet-out system, the amount of resin in the system, the hardener-to-resin ratio, and the level of inflation and pressure within the tank. Equipped with these measurements, the manufacturer is able to manage the balance between weight and strength and build the most accurate record of the tank. This allows the exact details of the tank’s manufacture to be traced back to the process in the future and used to identify trends, change recipes, and develop the process further. The data also facilitates
recycling of the composite part at the end of its life.

Test cell

The full, production-scale winding cell at Cygnet Texkimp’s UK innovation centre is one of very few facilities in the world where manufacturers can explore a complete automated process, using their own applications to develop bespoke solutions (Figure 2). The space is equipped with over €13,770 M (£12 M) of equipment from across the company’s fibre handling and processing portfolio. The facility is designed to enable composite manufacturers to develop and test the most appropriate solution for their exact needs. Cygnet Texkimp is currently working with several partners to support the development of Type III and IV tanks at rate. However, this machine also has the capability to produce Type V and cryogenic tanks, which are of significant interest to
aerospace and space programmes. Hydrogen storage and distribution is another area of growth that is also beginning to be explored, given that moving and storing large volumes of hydrogen requires high numbers of very large tanks.