From sheet to fleet

Bindatex – Europe’s only independent supplier of precision cutting services to the composites sector – explores the behind-the-scenes processes involved in making composite materials ready for use. Composite materials are, of course, abundant in the manufacturing world, with more and more industrial uses being discovered. However, one area that is often forgotten is what happens before composites reach the factory floor. Composite materials end up with a variety of applications within the aerospace, automotive, oil and gas, wind energy, motorsport and nuclear industries – to name just a few – so, how does it happen? Bindatex sits between the carbon fibre prepreg material manufacturer and the composite part manufacturer as the only independent provider of slitting, cutting and sheeting services for composites in Europe. Chris Lever, managing director at the North West-based company, explains how Bindatex fits in to the process: “Essentially, precision cutting transforms, wide rolls of composite materials into smaller panels or shapes or, more commonly, to continuous narrow tapes. In this form, the material is much more flexible and can be manipulated into the structure required for the production of radomes and also for use in filament winding processes, for instance. “As a provider of pre-cut composites, we’ve developed and invested a lot of time and money over the years in the bespoke machinery that we use. We have adapted our skills and knowledge, which originated in the textile industry, to fill a gap in the manufacturing sector for the handling of composites, and we now see a huge amount and variety of carbon fibre and prepreg composites pass through our doors every day – from unidirectional carbon fibre and woven glass prepreg to multiaxial materials. The major and critical consideration during this pre-manufacture stage is time. With many composites manufacturers outsourcing the handling and cutting of their materials, an effective and swift supply chain is crucial to the entire manufacturing process. Small and flexible The pace of the supply chain in the composites sector can be hampered by long lead-times. As a small, independent business which does not have a minimum order quantity, Bindatex is able to fulfil small orders quickly whilst freeing up larger composites suppliers to ensure large-scale projects are completed effectively, without disruption, to high-volume production lines. The various material types converted to precision tapes by Bindatex have been utilised recently in a number of automated composite research programmes. In conjunction with a UK-based military aerospace manufacturer, The University of Sheffield Advanced Manufacturing Research Centre (AMRC) and the National Composites Centre (NCC), Bristol, Bindatex has explored the benefits and applications of advanced, automated fibre placement equipment. Lever continues: “In response to increasing demand for converted composites and to facilitate a quick turnaround of orders, the advancement and modification of the machinery we use has been imperative. Different sectors require varied solutions, so being able to easily and swiftly adjust our machinery is key. Additions to our narrow width slitting and spooling line, for example have allowed us to duplicate the amount of product that can be processed at a time and therefore increase overall production and efficiency. “In addition, we’ve implemented technologies and developed processes that closely monitor the machinery, such as our camera inspection system – foreign object damage (FOD) – to help limit faults and inaccuracies. This ensures quality control and eliminates human error, which ultimately reduces time and cost.” Bindatex can slit prepreg composite materials down to widths as narrow as 3.175mm to the high tolerances demanded by aerospace applications on finished slit coils. The resulting tapes of material, once accurately laid adjacent to each other, are then cured to form the desired structure – whether it is for a bicycle wheel or a part of a nuclear fusion reactor. Before this can happen, though, the product needs to be transported to its destination quickly and suitably stored which, due to the nature of the product, is not always as simple as it sounds. Lever explains: “Many of the materials we deal with have a short shelf life if kept at room temperature. UD carbon fibre prepreg, for instance, needs to be stored at -18°C – otherwise, the epoxy resin begins to cure after about 30 days, rendering the material useless. Because of this, these materials need to be stored at low temperatures and transportation must be as fast as possible for the product to be received and manufactured into the desired structure in time.” Facilities on-site to store products at -18°C prior to and after cutting, together with its UK location, make Bindatex especially suited to supply Europe-based manufacturers, as it allows them maximum time to use the materials. Aerospace sector engagement Historically, the aerospace industry has been the driving force behind innovation and progress in composites manufacturing and, with the aerospace sector expected to grow at a rate of 6.8% over the next few years, the volume and variety of materials that need to be cut is increasing. Lever adds: “Automated tape laying and automated fibre placement – computerised processes which lay one or several layers of carbon fibre tape or tows around a composite tooling to create a part or structure – have long been used in the aerospace industry, reducing the need for manual production. Typically, they’re used for applications like aircraft wing skins and fuselages, but these processes are now being used across other sectors.” This year alone has seen a £15 billion boost to the UK aerospace industry, with more than 900 commercial aeroplanes having been produced since January, whilst the application of composites also continues to expand across industries. For example, the renewable energy sector – which is projected to grow to ensure it can meet carbon emission reduction targets – has seen a surge in the use of composites for wind turbines. The boost has also helped safeguard around 111,000 high-tech jobs in the UK, including those at Bindatex. Lever concludes: “The demand for a new generation of manufacturing process for thermosets and thermoplastics is inevitable. This calls for a proactive and innovative approach to cutting services within the composites sector and an efficient and timely supply chain – a challenge we relish!” www.slittingandsheeting.co.uk