Category Archives: Market

Bombardier Learjet 85- OoA prepreg and infusion process

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Bombardier Learjet 85- OoA prepreg and infusion process

At the end of the year we have thought it would be interesting to review one of the most interesting discussions we have had in our activity on linkedin. It was at the Composites Group. The news that Bombardier was using dry fiber and Resin Transfer infusion on the Learjet 85 wing box started an enriching discussion about the technical difficulties and possibilities of resin infusion processes and out of autoclave curing.

Learjet-85-mockupLearjet 85

Bombardier Learjet – composite

“Bombardier unveils OoA composites process for Learjet. Wingskins and spars for the plane are manufactured in Belfast using an in-autoclave resin transfer infusion (RTI) process. The fuselage and autoclave are manufactured in Querétaro, Mexico, via an out-of-autoclave (OOA) prepreg process.”

“ It makes use of composites not only to reduce airframe weight and increase fuel economy, but also to significantly reduce the part count because composites have enabled Learjet to produce large, integrated structures.”- Composites World

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-Sampe Europe 2014: from aerospace OoA to automotive thermoplastics

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The title of the 35th International Technical Conference & Forum organized by SAMPE was “Low cost Composite Processing, from Aerospace OOA to Automotive Thermoplastic”. As the title indicates the main issues were the way to decrease the manufacturing cost in aerospace composites and the relation between thermoplastics and composites in automotive.

As it is known, it is very important to avoid the autoclave in order to reduce the composites manufacturing

  • reducing tooling cost for component development and low-rate production runs
  • adding capability for manufacturing of very large highly integrated composite components
  • reducing capital costs for autoclave and associated facilities
  • and removing autoclave bottleneck for production

Different methods for avoiding the autoclave were discussed along the conference, the experts presented different projects related to this subject, focused on the use of NCFs and resin infusion methods (summarized below).

Taking into account the unique challenge of increasing the presence of composites in new single aisle aircraft, current works are targeting at developing robust, fully automated processes for the realization of large scale structures. New functionalities are being added to existing materials, like e.g. enhancing conductivity for the improvement of lightning strike behavior.

On the other hand, thermoplastic materials are being optimized and, last but not least, new multi-functional composite materials are under development to broaden the range of composite applications. In addition, huge efforts are being undertaken to enable structural bonding for composite repair.

With respect to the automotive application, the use of carbon fiber reinforced thermoplastic was considered the next challenge. The laser assisted and induction processes in welding and heating with thermoplastics were the most important topics of discussion.

Related to the main subject of the DRY COMPOSITES blog, some projects have been outlined from the conference:

  • In terms of OoA manufacturing technologies by means of NCF and RTM, Airbus Military presented its BAHIA project, focused on alternative fan cowl doors configuration and manufacturing.  Within the project framework a new fan cowl door is designed and a RTM technology is used in order to manufacture the structure, by eliminating 2 autoclave curing cycles and joining grid and skin through a unique bonding line. This way, Airbus Military intends to obtain a more competitive and reliable product.

       Co-authors: Javier Gomez Vega, Maria Antonia River Orellana, Luis Rubio García

Airbus 340-642 fan colw door

Airbus 340-642 fan cowl door

  • Researches from Irish Centre for Composite Research, MSSI and University of Limerick presented a design of experiments study assisted in optimising the LRI manufacturing process (liquid resin infusion). According to them, LRI processes is challenging due to the difficulty in achieving full fibre wet-out, target fibre volume fraction and acceptable void content etc. In this study, flat composite panels were manufactured using aerospace grade Benzoxazine resins systems (one of which is targeted at high temperature applications) and aerospace grade carbon fibre NCF (non-crimp fabric with and without powder binder).

      Co-authors: Anthony Comer, Dipa Ray, Winifred Obange, Gearoid Lancy, Inga Rosca, Walter    Stanley

Double-omega stiffened skin manufactured by VIM using Benzoxazine B.

Double-omega stiffened skin manufactured by VIM using Benzoxazine B.

  • Other EADS, Eurocopter and University of Stuttgart researchers did also present a study, aimed at the fundamental material behavior of such unidirectional-braided structures, which are converted from carbon-fibers and thin thermoplastic auxiliary-yarns directly to the part geometry as UD-plies. The promising results emphasize the feasibility of using UD-braiding for structures with high stiffness as well improved damage resistance.

Co-authors: C. Metzner a, A. Gessler a, C. Weimer a, U. Beier b, P. Middendorf

UD-braiding – the machine, process and textile

UD-braiding – the machine, process and textile

 

-AeroComposit chooses innovative solutions to build MS-21 composite wings

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MS-21´s wing spars, wing skins and six section panels will be manufactured by resin infusion and oven curing

Resin infusion is being applied in the newest commercial aviation programmes. One of them is the Irkut´s Corporation´s (Russia) MS-21 aircraft, which could be rolled out in 2015 (prototype). The post offers some details about the MS-21 aircraft, as well as about the innovative resin infusion technology they are applying in order to push the Russian companies at the the forefront of the worldwide aircraft industry.

Although Irkut will only produce 40 aircrafts/year (compared to approximately 500 each for Airbus and Boeing), the new MS-21 could compete with worldwide market leaders in the single-aisle commercial jet market.

Irkut MS-21 aircraft

Irkut´s MS-21 aircraft

To succeed in this highly competitive market, Irkut´s aircraft will have to offer a good performance and a greater fuel efficiency than its competitors. MS-21 will have a lower empty weight, a better aerodynamics and more efficient engines. The company is confident that if the MS-21 can use composites in a way that reduces weight and manufacturing costs in that 45 percent with a a target price of 35 Million US$.

To this end, in terms of technology, the company has decided to go one step ahead ,since the very beginning of the programme definition, being at the cutting edge of the aircraft industry, using Out of Autoclave methods for structural parts manufacturing.

Infusion and oven curing have been chosen for the MS-21’s large integrally stiffened primary structures including the wing spars, wing skins and six section panels

Infusion and oven curing have been chosen for the MS-21’s large integrally stiffened primary structures including the wing spars, wing skins and six section panels for the centre wing-box. These will be manufactured and assembled at the AeroComposit (also subsidiary of UAC) plant in Ulyanovsk. These process have been chosen due to its potential to reduce costs (avoiding the costly autoclave curing and reducing resin and dry material costs), and its opportunity to create integral constructions.

MS-21 resin infused wing

MS-21 resin infused wing (Diamond Aircraft´s photo)

AeroComposit has worked with a variety of experts worldwide to develop the design, materials and the process to achieve the requisite precision and quality. In terms of raw material, Hexcel and Cytec have been selected to provide dry carbon fiber and compatible liquid epoxy infusion resin. Hexcel´s OoA HiTape (up to 30mm thick) and it´s HexFlow infusion resin have been already tested to be used for the wing manufacturing.  The company affirms that 58 to 60% fiber volume content can be achieved with these  materials. An equivalent system from Cytec is also being used in the project.

The wing is based on the new carbon-infusion technology that allows building big components, like tail units or wings, with high stability at low weight.

Regarding the infusion process, FACC and Diamond Aircraft will be responsible for optimizing the wing and wing-box manufacturing process. Diamond Aircraft has developed the resin infusion process for the wing manufacturing. The wing is based on the new carbon-infusion technology that allows building big components, like tail units or wings, with high stability at low weight. The resin is cured at an aerospace standard of 180°C/356°F with a service temperature of -60°C to 160°C (-76°F to 320°F) while the production cycle can vary from 5 to 30 hours. The manufactured wing meets the requirements of the aircraft industry with a porosity of 0,3%. Diamond Aircraft claims that this achievement does not depend on the type of construction, but instead on the ability to maintain strict control of the process parameters. According to the company, the prototype wing is a a great achievement, that will have a mayor impact on the design of future airlines.

You can find more information in these CompositesWorld, Diamond Aircraft and Russia Beyond the State of the Art articles.

-BMW i3: first mass produced composite car in production

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BMW has started production of its revolutionary i3 city car, which is the first mass-produced automobile using a composite frame. The company invested $533 MM (€ 400 MM) in its composite and assembly facilities in Germany and expects first deliveries to European customers in November. Production facilities have been sized to support a rate of 40,000 vehicles per year.

BMW i3: first mass produced composite car

BMW i3: first mass produced composite car

The heart of the structure is the 330 pound (150 kg) passenger compartment, called the Life Module. It is made from dry, carbon non-crimp fabric (NCF) preforms that are resin transfer molded (RTM). This permits substantial parts integration of the Life Module comprising 150 parts total, with two thirds fewer parts and 50% less production floor space than with a steel design, according to BMW. Parts consolidation of this magnitude cannot be achieved using steel or aluminum according to BMW’s Project Director Dr. Carsten Breitfeld. The Gr/Ep Life Module weighs half of a steel design, and contributes to total vehicle weight savings of 770 pounds (350 kg).

Production cost and rate of the i3 composite structure are critically important. Compared with existing production of composite parts for the BMW M3 and M6, 50% cost savings are realized with the i3 process and cycle time is reduced by 30%. “We have optimized the process, achieved a shorter manufacturing time, and succeeded in taking a lot of the cost out” says Breitfeld. He attributes these achievements to “a fresh approach to manufacturing and materials use and a very clear business plan…… The production process is a very significant time saver and means that industrialization of large CFRP components is now realistic.”

BMW’s experience has been so favorable that its larger i8 electric sports car to be offered next year will be built the same way.

More details are provided in SAE Automotive Engineering and CompositesWorld articles.

 

 

-Aerospace Looking to Dry Fiber/Infused Composites

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Most aerospace composite structures are produced today using prepreg and autoclave cure. Recently an increasing number and type of large and critical structures are being manufactured in a very different way – using Preforms assembled from dry fabrics and tapes and then infusing the epoxy resin into the Preform followed by cure. If the infusion is performed in a matched closed mold under high pressure, the process is called RTM. For many larger parts, infusion is performed using vacuum pressure only with single surface tools. This process has many different names reflecting slight differences in the infusion process including VARTM, CAPRI, VAP, RTI, RFI, BRI, SCRIMP and several others.

A wide range of aerospace parts are fully qualified and in production today made from dry fiber and vacuum infusion – a few examples are shown below. Some of these assemblies, such as flight control surfaces (flaps and ailerons) and fuselage frames are considered secondary or redundant components. Others such as the Aft Pressure Bulkheads of the A380 and 787 are primary structure – failure of these critical components would likely lead to loss of the aircraft. The A400 Cargo Door operates in an even more challenging environment – this flat and large door sees full cabin pressurization, and experiences significant bending  and tension loads during flight.

That these highly critical parts are made using these materials and processes speaks to the high degree of confidence that the aircraft OEM’s and regulatory authorities have in the reliability, performance and safety of the dry fiber/infusion approach.

787 Dry fiber/infused parts include (left to right) ailerons and flaps, fuselage frames and the aft pressure bulkhead (APB) of the fuselage

787 Dry fiber/infused parts include (left to right) ailerons and flaps, fuselage frames
and the aft pressure bulkhead (APB) of the fuselage

A380 Aft Pressure Bulkhead (APB) and A400 pressurized Cargo Door

A380 Aft Pressure Bulkhead (APB) and A400 pressurized Cargo Door

Arguably the most advanced use of dry fibers and infusion is in the wings of next generation airliners such as the Bombardier CSeries and Irkut MS21 aircraft shown below. These aircraft, serving 120 to 200 passengers, are the newest in commercial aviation and have leveraged the latest advances in composite materials, processes and production methods available today. The CSeries has passed ground structural tests and is expected to make its first flight mid 2013, with the MC21 to follow about a year later.

The Bombardier CSeries wing (left) and Irkut MS21 wing (right) both are made from dry fiber preforms and resin infusion

The Bombardier CSeries wing (left) and Irkut MS21 wing (right) both are made from dry fiber preforms and resin infusion

How about your company – is this technology being considered and for what applications? What are the benefits, tradeoffs, concerns and issues associated with the use of these processes? Let us know what you think.

-Advanced dry composite materials offer new opportunities in the aerospace industry

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The number of flights expected for the next 2 decades shows a an annual growth rate of 4.7%, but needs to satisfy very tight constrains on fuel consumption (with fuel consumption being about 30% of the operating cost). It is required to strongly reduce fuel consumption of the future aircrafts manufactured.


ScreenHunter_1350Growth perspective for annual flights from AIRBUS market forecast

One of the approaches required to do so is the introduction of advanced materials to reduce their weight, and composite materials in particular. Major manufacturers have increased the content of composite materials from 5% (A300) to 52% (A350XWB) for AIRBUS or to 46% for the CSeries (Bombardier), including wings, fuselage, and other structural parts etc.

Traditionally, structural components in aerospace have used carbon fiber pre-impregnated with epoxy resins (pre-pregs) that require to be cured in an Autoclave. Although the properties of the pre-pregs are outstanding, the cost associated to the maintenance, shelf life and autoclave processing of these pre-pregs represents a high percentage of the total cost of the part.

In order to reduce these costs, a strong effort has been performed to develop dry composite materials with suitable material properties, and reduced manufacturing costs due to higher deposition rates, no costs of refrigeration, and longer shelf life.  Due to this effort, the use of dry composite materials emerges as a new material feasible for the manufacture of structural components.

The CSeries Aircrafts, from Bombardier Aerospace represents a breakthrough in the use of composite materials, since some of their structural components, such us the wings are being manufactured using dry composite materials. Bombardier expects to reduce 20% the fuel consumption, and have 25% less maintenance costs. The CSeries aircraft is expected to make the first flight shortly. In particular, the manufacturing process is based on pick and place of dry composite material cut on a 2D table and positioned in the mould.

Bombardier

Bombardier is not the only one aircraft manufacturer that uses dry composites in the design of the new aircraft to reduce costs and increase productivities: A400M from AIRBUS cargo door (also a structural component) is also manufactured using dry composite materials. Furthermore, their manufacturing method uses alternatives to autoclave, by means of the VAP (vacuum-assisted process) demonstrating that dry composite materials can achieve mechanical properties required to be used in structural components. The manufacture of these components also takes benefit of the combined infusion of the different parts (skin and stringers), avoiding about 3000 metallic rivets.

0507HPC_IM_A400M_Step_3The investigation and development on dry composites, offers a critical opportunity to push forward the presence of composite materials in the aeronautic field by reducing costs, and maintaining the mechanical properties of pre-preg materials.

Airbus and Bombardier are setting up the first steps regarding the use of dry composites in the aeronautic sector. This sets the path to the industrial development of processing technologies of the fabrication of the materials and the components, and moving from manual manufacturing for short series to high production for larger series, as has happened with glass fiber or pre-preg carbon fiber materials.

There are still strong challenges remaining to take full advantage of this disruptive material that require a strong synergy between all the agents responsible of the introduction, design and development of components manufactured from dry composite materials: companies, Research Centers, academics and experts.