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Bio-based, fire-resistant composites become mainstream | CompositesWorld

The U.S. Air Force conducted on-base and cross-country mission and performance evaluations of Beta’s composites-intensive CTOL aircraft, hitting key milestones.

Horizontal and vertical tail, aileron, and rudder and elevator will be developed and manufactured for the lift + cruise aircraft, scheduled to enter service in 2026. shoe material

Bio-based, fire-resistant composites become mainstream | CompositesWorld

In addition to its composite aircraft, Overair will support infrastructure, aircraft operations and training to ensure a comprehensive and sustainable AAM ecosystem.

This initial project under the Space Act Agreement is focused on studying and developing high-performance battery cells, as well as performing safety testing, to achieve purpose-built solutions for electric aircraft.  

AeroZero TPS, applicable for metals and composites, will protect critical battery housing and parts in the Lilium Jet eVTOL aircraft from burn through and risk of thermal runaway.

V-tail, five-passenger aircraft builds on the vison of the S-A1, designed with a priority on safety and a focus on sustainability.

The new alliance will broaden National Composites’ capabilities in SMC and BMC and tooling, while providing customers with comprehensive solutions, from initial design to final delivery.

A new ASTM-standardized test method established in 2022 assesses the compression-loaded damage tolerance of sandwich composites.  

Composites automation specialist increases access to next-gen technologies, including novel AFP systems and unique 3D parts using adaptive molds.

Combined LSAM and five-axis CNC milling capabilities will optimize D-Composites’ production services, flexibility and cut time and cost for composite tooling manufacture.

Evaluation of CFRTP m-pipe through Element’s U.K. facility aims to qualify the system for new operating environments.

Innovative prepreg tooling is highly drapable, capable of forming complex carbon fiber tooling shapes, in addition to reducing through thickness porosity and only requiring one debulk during layup.

Inshore vessel is the largest yet to incorporate the recyclable thermoplastic resin, promotes future sustainability in boat manufacturing.

Projects use Duplicor prepreg panels with highest Euroclass B fire performance without fire retardants for reduced weight, CO2 footprint in sustainable yet affordable roofs, high-rise façades and modular housing.

Available as filament and granules for extrusion, new wood composite matches properties yet is compostable, eliminates microplastics and reduces carbon footprint.

A recent study conducted on vacuum-infused thermoplastic fiber-metal laminates has highlighted the performance benefits behind using TFP’s nonwovens for consistent, uniform bondlines and interfacial bonding.

To incorporate more environmentally conscious practices into its manufacturing processes, VSC is working with Carbon Conversions to reclaim, recycle and reuse its carbon fiber materials.

Switching from prepreg to RTM led to significant time and cost savings for the manufacture of fiberglass struts and complex carbon fiber composite foils that power ORPC’s RivGen systems.

Automated fiber placement develops into more compact, flexible, modular and digitized systems with multi-material and process capabilities.

Available as filament and granules for extrusion, new wood composite matches properties yet is compostable, eliminates microplastics and reduces carbon footprint.

A recent study conducted on vacuum-infused thermoplastic fiber-metal laminates has highlighted the performance benefits behind using TFP’s nonwovens for consistent, uniform bondlines and interfacial bonding.

Switching from prepreg to RTM led to significant time and cost savings for the manufacture of fiberglass struts and complex carbon fiber composite foils that power ORPC’s RivGen systems.

Sara Black’s 2015 report on the development of snap-cure epoxies for automotive manufacturing still resonates today. 

JEC World 2024: Zünd is highlighting digital excellence via its ZCC Cut Center, heat sealing module (HSM), G3 Cutter and ZPC software.

CW explores key composite developments that have shaped how we see and think about the industry today.

Knowing the fundamentals for reading drawings — including master ply tables, ply definition diagrams and more — lays a foundation for proper composite design evaluation.

As battery electric and fuel cell electric vehicles continue to supplant internal combustion engine vehicles, composite materials are quickly finding adoption to offset a variety of challenges, particularly for battery enclosure and fuel cell development.  

Performing regular maintenance of the layup tool for successful sealing and release is required to reduce the risk of part adherence.

Increasingly, prototype and production-ready smart devices featuring thermoplastic composite cases and other components provide lightweight, optimized sustainable alternatives to metal.

The composite pressure vessel market is fast-growing and now dominated by demand for hydrogen storage.

The burgeoning advanced air mobility (AAM) market promises to introduce a new mode of transport for urban and intercity travelers — particularly those who wish to bypass the traffic congestion endemic to the world’s largest cities. The electric vertical take-off and landing (eVTOL) aircraft serving this market, because they depend on battery-powered propulsion, also depend on high-strength, high-performance composite structures produced at volumes heretofore unseen in the aerospace composites industry. This CW Tech Days will feature subject matter experts exploring the materials, tooling and manufacturing challenges of ramping up composites fabrication operations to efficiently meet the demands of a challenging and promising new marketplace.

Manufacturers often struggle with production anomalies that can be traced back to material deviations. These can cause fluctuations in material flow, cooling, and cure according to environmental influences and/or batch-to-batch variations. Today’s competitive environment demands cost-efficient, error-free production using automated production and stable processes. As industries advance new bio-based, faster reacting and increased recycled content materials and faster processes, how can manufacturers quickly establish and maintain quality control? In-mold dielectric sensors paired with data analytics technology enable manufacturers to: Determine glass transition temperature in real time Monitor material deviations such as resin mix ratio, aging, and batch-to-batch variations throughout the process Predict the influence of deviations or material defects during the process See the progression of curing and demold the part when the desired degree of cure, Tg or crystallinity is achieved Document resin mix ratios using snap-cure resins for qualification and certification of RTM parts Successful case histories with real parts illustrate how sensXPERT sensors, machine learning, and material models monitor, predict, and optimize production to compensate for deviations. This Digital Mold technology has enabled manufacturers to reduce scrap by up to 50% and generated energy savings of up to 23%. Agenda: Dealing with the challenge of material deviations and production anomalies How dielectric sensors work with different composite resins, fibers and processes What is required for installation Case histories of in-mold dielectric sensors and data analytics used to monitor resin mixing ratios and predict potential material deviations How this Digital Mold technology has enabled manufacturers to optimize production, and improve quality and reliability

SolvaLite is a family of new fast cure epoxy systems that — combined with Solvay's proprietary Double Diaphragm Forming technology — allows short cycle times and reproducibility. Agenda:  Application Development Center and capabilities Solutions for high-rate manufacturing for automotive Application examples: battery enclosures and body panels

OEMs around the world are looking for smarter materials to forward-think their products by combining high mechanical performance with lightweight design and long-lasting durability. In this webinar, composite experts from Exel Composites explain the benefits of a unique continuous manufacturing process for composites profiles and tubes called pull-winding. Pull-winding makes it possible to manufacture strong, lightweight and extremely thin-walled composite tubes and profiles that meet both demanding mechanical specifications and aesthetic needs. The possibilities for customizing the profile’s features are almost limitless — and because pull-winding is a continuous process, it is well suited for high volume production with consistent quality. Join the webinar to learn why you should consider pull-wound composites for your product. Agenda: Introducing pull-winding, and how it compares to other composite manufacturing technologies like filament winding or pultrusion What are the benefits of pull-winding and how can it achieve thin-walled profiles? Practical examples of product challenges solved by pull-winding

Composite systems consist of two sub-constituents: woven fibers as the reinforcement element and resin as the matrix. The most commonly used fibers are glass and carbon, which can be processed in plane or satin structures to form woven fabrics. Carbon fibers, in particular, are known for their high strength/weight properties. Thermoset resins, such as epoxies and polyurethanes, are used in more demanding applications due to their high physical-mechanical properties. However, composites manufacturers still face the challenge of designing the right cure cycles and repairing out-of-shelf-life parts. To address these issues, Alpha Technologies proposes using the encapsulated sample rheometer (premier ESR) to determine the viscoelastic properties of thermosets. Premier ESR generates repeatable and reproducible analytical data and can measure a broad range of viscosity values, making it ideal for resins such as low viscous uncured prepreg or neat resins as well as highly viscous cured prepregs. During testing, before cure, cure and after cure properties can be detected without removing the material from the test chamber. Moreover, ESR can run a broad range of tests, from isothermal and non-isothermal cures to advanced techniques such as large amplitude oscillatory shear tests. During this webinar, Alpha Technologies will be presenting some of the selected studies that were completed on epoxy prepreg systems utilizing ESR and how it solves many issues in a fast and effective way. It will highlight the advantages of this technique that were proven with the work of several researchers. Moreover, Alpha Technologies will display part of these interesting findings using the correlations between the viscoelastic properties such as G’ and mechanical properties such as short beam shear strength (SBS).

Surface preparation is a critical step in composite structure bonding and plays a major role in determining the final bonding performance. Solvay has developed FusePly, a breakthrough technology that offers the potential to build reliable and robust bonded composite parts through the creation of covalently-bonded structures at bondline interface. FusePly technology meets the manufacturing challenges faced by aircraft builders and industrial bonding users looking for improved performance, buildrates and lightweighting. In this webinar, you will discover FusePly's key benefits as well as processing and data. Agenda: Surface preparation challenges for composite bonding FusePly technology overview Properties and performance data

Venue ONLY ON-SITE @AZL Hub in Aachen Building Part 3B, 4th Floor Campus Boulevard 30 52074 Aachen Time: January 31st, 2024 | 11:00-16:00h (CET) This first constitutive session will shape the future of the workgroup. ✓ Insights into solutions for e.g. circularity, recycling, sustainability, end of life etc. ✓ Interactive exchange along the value chain to tackle these challenges: Share your input in the “World Café” workshop session! ✓ Are you a solution provider? Take your chance and present your solution approach in a short 5-minute pitch. Get in touch with Alexander.  

The Transformative Vertical Flight (TVF) 2024 meeting will take place Feb. 6–8, 2024 in Santa Clara, California, in the heart of Silicon Valley and will feature more than 100 speakers on important progress on vertical takeoff and landing (VTOL) aircraft and technology. 

The EPTA – European Pultrusion Technology Association in cooperation with the American Composites Manufacturers Association (ACMA) invites you to the 17th World Pultrusion Conference which takes place on 29 February – 1 March 2024 in Hamburg, Germany. Visit the most important event in Europe in the market for pultruded fiber reinforced materials  This conference takes place every two years and is the meeting point of the European and worldwide Pultrusion Industry. More than 25 international speakers from Finland, Belgium, Germany, France, Spain, The Netherlands, Turkey, UK, USA, Canada and others will present practical presentations about innovative applications, technologies and processes. Equally current market trends and developments are on the agenda. This World Pultrusion Conference takes place again in the week before the JEC World Composites Show (5-7 March 2024, Paris). The presentation language will be English. Please finde here the full program and booking opportunities. We appreciate very much welcoming you in Hamburg! Inquiries should be requested by email: info@pultruders.com

The Program of this Summit consists of a range of 12 high-level lectures by 14 invited speakers only. Topics are composite related innovations in Automotive & Transport, Space & Aerospace, Advanced Materials, and Process Engineering, as well as Challenging Applications in other markets like Architecture, Construction, Sports, Energy, Marine & more.

JEC World in Paris is the only trade show that unites the global composite industry: an indication of the industry’s commitment to an international platform where users can find a full spectrum of processes, new materials, and composite solutions.

Charting the Skies of Tomorrow: The Sustainable Aviation Revolution Welcome to a new era of air travel where innovation meets sustainability. Electric, hybrid-electric and hydrogen-powered aircraft represent a promising path to reach climate neutrality goals, with the aviation industry and governments jointly pushing boundaries to bring disruptive aircraft into service by 2035. From cutting-edge technologies to revamped regulations and greener airports, the pursuit of sustainable aviation requires unparalleled collaboration throughout the whole aviation value chain and ecosystem. Join us at the Clean Aviation Annual Forum from 5 until 6 March 2024, as we navigate towards cleaner skies together.

Thousands of people visit our Supplier Guide every day to source equipment and materials. Get in front of them with a free company profile.

Jetcam’s latest white paper explores the critical aspects of nesting in composites manufacturing, and strategies to balance material efficiency and kitting speed.

Arris presents mechanical testing results of an Arris-designed natural fiber thermoplastic composite in comparison to similarly produced glass and carbon fiber-based materials.

Cevotec, a tank manufacturer, Roth Composite Machinery and Cikoni, have undertaken a comprehensive project to explore and demonstrate the impact of dome reinforcements using FPP technology for composite tanks.   

Initial demonstration in furniture shows properties two to nine times higher than plywood, OOA molding for uniquely shaped components.

The composite tubes white paper explores some of the considerations for specifying composite tubes, such as mechanical properties, maintenance requirements and more.

Foundational research discusses the current carbon fiber recycling landscape in Utah, and evaluates potential strategies and policies that could enhance this sustainable practice in the region.

To incorporate more environmentally conscious practices into its manufacturing processes, VSC is working with Carbon Conversions to reclaim, recycle and reuse its carbon fiber materials.

As the marine market corrects after the COVID-19 upswing, the emphasis is on decarbonization and sustainability, automation and new forms of mobility offering opportunity for composites.

Novel material to combine Ohoskin’s leather alternative made from orange and cactus byproducts with ReCarbon’s recycled carbon fiber.

The three-year strategic collaboration will help boost the company’s growth, reinforce its commitments to become carbon neutral by 2040 and innovate more circular chemicals and materials.

Oak Ridge National Laboratory's Sustainable Manufacturing Technologies Group helps industrial partners tackle the sustainability challenges presented by fiber-reinforced composite materials.

Eco-friendly carbon fiber slashes carbon footprint by half through renewable energy, a commitment echoed in SGL’s Lavradio biomass plant set to reduce CO2 emissions by 90,000 tons.  

In the Automated Composites Knowledge Center, CGTech brings you vital information about all things automated composites.

This CW Tech Days event will explore the technologies, materials, and strategies that can help composites manufacturers become more sustainable.

Explore the cutting-edge composites industry, as experts delve into the materials, tooling, and manufacturing hurdles of meeting the demands of the promising advanced air mobility (AAM) market. Join us at CW Tech Days to unlock the future of efficient composites fabrication operations.

During CW Tech Days: Thermoplastics for Large Structures, experts explored the materials and processing technologies that are enabling the transition to large-part manufacturing.

Closed mold processes offer many advantages over open molding. This knowledge center details the basics of closed mold methods and the products and tools essential to producing a part correctly.

The composites industry is increasingly recognizing the imperative of sustainability in its operations. As demand for lightweight and durable materials rises across various sectors, such as automotive, aerospace, and construction, there is a growing awareness of the environmental impact associated with traditional composite manufacturing processes.

CompositesWorld’s CW Tech Days: Infrastructure event offers a series of expert presentations on composite materials, processes and applications that should and will be considered for use in the infrastructure and construction markets.

CW’s editors are tracking the latest trends and developments in tooling, from the basics to new developments. This collection, presented by Composites One, features four recent CW stories that detail a range of tooling technologies, processes and materials.

CompositesWorld’s CW Tech Days: Infrastructure event offers a series of expert presentations on composite materials, processes and applications that should and will be considered for use in the infrastructure and construction markets.

Explore the cutting-edge composites industry, as experts delve into the materials, tooling, and manufacturing hurdles of meeting the demands of the promising advanced air mobility (AAM) market. Join us at CW Tech Days to unlock the future of efficient composites fabrication operations.

Thermoplastics for Large Structures, experts explored the materials and processing technologies that are enabling the transition to large-part manufacturing.

Explore the technologies, materials, and strategies that can help composites manufacturers become more sustainable.

A report on the demand for hydrogen as an energy source and the role composites might play in the transport and storage of hydrogen.

This collection features detail the current state of the industry and recent success stories across aerospace, automotive and rail applications.

This collection details the basics, challenges, and future of thermoplastic composites technology, with particular emphasis on their use for commercial aerospace primary structures.

This collection features recent CW stories that detail a range of tooling technologies, processes and materials.

Projects use Duplicor prepreg panels with highest Euroclass B fire performance without fire retardants for reduced weight, CO2 footprint in sustainable yet affordable roofs, high-rise façades and modular housing.

Figure 1. Large-scale innovation, mainstream projects. Lightweight Duplicor prepreg composite panels have been used to restore 13,300 square meters of roofing for the Van Gendt Hallen heritage site (left), to enable The Pulse’s open-plan high-rise office tower (center) and to build 99 affordable yet flexible modular housing units for the Netherlands elderly care organization Cicero. Photo Credit, all images: Holland Composites/Duplicor, The Pulse of Amsterdam, flickr.com (center) and Qbix (right).

As explained in CW’s 2019 tour article, Holland Composites (Lelystad, Netherlands) has been developing composite solutions in architecture and construction for decades. The company’s first project, an energy-efficient 6 × 3 × 3-meter (l, w, h) modular housing unit for universities called Space Box, was an instant success, selling thousands of units. The company went on to complete a variety of high-profile projects, fabricating and installing composite roof structures and façades, including its Raficlad system of translucent composite panels that can be made in any color and incorporate visual fibers, logos or even dried organic matter.

But Holland Composites’ founders, Pieterjan Dwarshuis and Sven Erik Janssen, could see the industry needed a better solution than the carbon fiber-reinforced polymer (CFRP) and resin-infused glass fiber panels they had been using. “We faced a serious challenge with these composites in the mainstream building market because the polyester, phenolic and epoxy resins we were using are considered toxic materials,” explains Janssen. “It’s very difficult now to put these into buildings. The industry is instead looking to more natural and bio-based materials. The other issue is that these petroleum-based resins burn.”

“We were always struggling with getting the fire performance right with composite materials,” agrees Eric van Uden, managing director of Solico Engineering (Oosterhout, Netherlands). His company has provided structural engineering for Holland Composites construction projects since 2005. “We could use highly filled fire-retardant [FR] resins, but they were very costly. Because they had lower properties, we needed a lot of kilos of resin.” This then increased weight and demanded more structural support.

Now, however, Holland Composites is proposing what Janssen calls a game-changing solution: Duplicor bio-based, fire-resistant composites. “We’re using a plant-based resin with a mix of possible fibers depending on the application,” he explains. “And we no longer use PIR [polyisocyanurate] or EPS [expanded polystyrene] foams in sandwich construction, but just recycled PET foam.” The latter, he concedes, is not bio-based, “but it does help to remove plastics from the environment. Duplicor is durable, it actually stores CO2 and it is a solution to build with less material. More and more tenders in the building industry are being awarded not only on price, but also on the environmental impact of the materials and process that you use.” And, he adds, “Duplicor is affordable.”

This technology results not only from Holland Composites’ many years of learning in developing composites for marine and construction applications, but also years spent specifically on the Duplicor approach. “Seven years ago, we started working with a company that was experimenting with a resin they made from sugarcane straw, a kind of agricultural waste,” says Janssen. “But we couldn’t infuse with it. We finally asked one of our prepreg suppliers to try putting the resin into a prepreg and that was the key. But we also saw it had a really high temperature resistance, therefore it could have good fire resistance.”

Indeed, tests in 2019 showed the resin burned much less quickly than the company’s previous composites. By November 2020, testing by fire safety specialists Efectis (Saint-Aubin, France), per the European Standard EN 13501, showed Duplicor panels successfully achieved fire classification B-s1, d0. The certificate cites panels 15-150 millimeters thick, with 200 micrometers of ultra-high solids (UHS) paint, a 2.5-millimeter-thick glass fiber/bio-resin skin laminate (1,950 kilograms/cubic meter density) and 15- to 150-millimeter-thick PET foam core (40-60 kilograms/cubic meter density). “This means that Duplicor cored panels and solid laminates have no flame spread and are very hard to burn,” says Janssen.

“It’s not Grade A according to our European standard, but it reaches the highest level of the vertical combustible materials, which is actually the highest value you can reach with composite materials without any FR additives,” adds van Uden. “That’s enough for use in European buildings. The regulation is that the first 3 meters should be Class B and then up to 12 or 14 meters you can have Class C or D. Above 30 meters that should again be Class B. So, this material suits as-is for all building applications.”

Holland Composites continued development, patenting the Duplicor technology and bringing fabrication in-house. In 2021, it built a second 4,000-square meter factory, next to the original Holland Composites building in Lelystad, dedicated to Duplicor production (see Fig. 3 below).

Duplicor prepreg and composite panel production.

The brownish-colored resin arrives in bulk containers. “We mix it with accelerators and a thermal hardener, and then feed that into our prepreg machine,” says Janssen. “We have installed a 35-meter-long prepreg manufacturing line which is the same that is used for carbon fiber/epoxy prepregs, but custom made for us. We can make thousands of square meters of Duplicor prepregs with high fiber content. These are not 200 gram/square meter carbon fiber/epoxy prepregs, but instead materials for 1,600-gram quadraxial laminates with 35% resin content. So, you’re talking about a 2.5 kilogram/square meter prepreg material, which is designed for building purposes — i.e., one layer and done.”

Rolls of prepreg are produced according to the specifications for each project and then converted into panels. To further aid production speed, Zund (Altstätten, Switzerland) automated cutters are used to cut the prepreg, which pick-and-place robots then put into molds. “We then use the set of skills developed for Holland Composites’ projects,” says Janssen. “We can use these molds in a hot press, oven or autoclave to make profiles, laminate sheets or simple sandwich panels.” The Duplicor factory has two 12-meter-long hot-press production lines which can produce panels or profiles up to 3.5 meters long and 1.25 meters wide. It also has four ovens, sized roughly 4 × 4 meters. Parts can also be made next door using Holland Composites’ 6.5 × 2.2-meter autoclave, its 12 x 4-meter heated vacuum table — traditionally used for resin infusion — or one of several modular ovens developed to expand up to 15 × 10 × 3.5 meters for large marine projects.

“One of the first things we had to do was to determine the engineering parameters so we could design with Duplicor and ensure we meet the Eurocodes building standards in Europe,” explains van Uden. “We did a whole test program with Holland Composites to characterize Duplicor materials in terms of stiffness, strength and degradation due to moisture, temperature, etc. We tested different varieties of their material with biaxial fabrics, woven roving and unidirectional [UD] reinforcements, as well as different core materials.”

The Duplicor laminates were higher in performance than previous composites. “We began discussing how we could make structures thinner,” says van Uden. “With the previous process, that always seemed difficult to do. We would have a 200-300-millimeter-thick foam core wrapped with dry fibers and then injected with resin. But with this new prepreg system, we could make structures more like shells so that if we needed core material to stiffen panels, then it is only 10-20 millimeters thick.”

That makes a huge difference, says Janssen. “So, we are using less material in a thinner panel, but because it’s an integrated panel with this recycled PET foam, we can provide a high thermal insulation factor of 5.8-6.0 with a thickness of only 180 millimeters. A concrete panel with the same properties is almost 400 millimeters thick because they have to add insulation foam. Thus, with Duplicor, we can offer wall panels that are 15 to 22 centimeters slimmer compared to traditional aluminum/wooden and concrete constructions, which provides extra usable floor space. In Amsterdam, you easily pay €5,000 per square meter for that floor space.”

LCA study comparing Duplicor to conventional façade construction where HSB stands for timber frame construction. *The carbon footprint of the Duplicor façade panel also includes transport. Photo Credit: Duplicor LCA report from CE Delft

Holland Composites also studied Duplicor’s carbon footprint compared to concrete and wooden frame construction (abbreviated as HSB in the Netherlands). In 2021, it commissioned a lifecycle analysis (LCA) study from the sustainability research and consulting firm CE Delft. The study compared Duplicor to three traditional constructions for façades based on an R-value of 5.8 to 6.0. Note that typical R-values per inch thickness are 0.8 to 1.2 for concrete, 1.25 for softwood lumber and 5.0 for extruded polystyrene foam. “The analysis showed that we can achieve that insulation performance in a structural facade weighing just 24 kilograms per square meter,” says Janssen. “Compare that to concrete at 450 kilos per square meter. So, we actually offer more space for the same building plan and use less material.”

Results from the LCA study comparing the four façade panels showed Duplicor offered superior performance: 3-4 times lower thickness, 5-30 times lower weight and 2-6 times lower carbon footprint. “If you use plant-based materials, you actually store CO2,” notes Janssen. How these benefits can be exploited in mainstream building projects is highlighted in the following case histories.

The Pulse is a two-tower, 56,000 square-meter development being completed in Amsterdam’s Zuidas business district. It was designed by well-known architects MVSA (Netherlands) to integrate a state-of-the-art office tower and a high-rise residential building with an urban forest and walkpath as well as restaurants, a cinema and supermarket. Duplicor was selected for the façade of the 24-story office tower, which features natural light and sweeping views via some of the largest, open-plan offices in the Netherlands. Construction began in 2021.

“The design of the building’s façade is canting more as you move up,” notes Janssen. “With every floor, the glass window leans a bit more forward. MVSA also used different element types on each floor to create some movement in the design. So, there are 16 different types of façade elements and also a one-piece corner element — all with the glass window integrated into them.”

The design for the Duplicor façade began with engineering partner Solico. “It started with Holland Composites’ idea of having a box-like structure with an outer and inner shell,” recalls van Uden. “You could then fill in that gap with a combination of recycled PET foam and rock wool or even blown-in insulation. Each element would then come out of the mold as an integrated structure with outer and inner shell and insulation material, but it also needed to be cost-effective. And that was really a new way of making these kinds of structures.”

“We then made finite element models for each type of element,” he continues, “and used those to determine wind loads, snow loads and self-weight to deal with the glass, which is actually the majority of the weight because the composite itself is quite light. We made our first calculations and then we started to optimize. For example, we needed some extra stiffening in some corners and more shape in some panels to accommodate insulation, etc.”

Figure 2. Enabling light-filled, flexible, sustainable spaces. The Pulse office tower uses Duplicor composite façade elements as the load-bearing closure between its concrete floors. The molded units integrate solar panels on top and canted, floor-to-ceiling glazing to achieve the building’s innovative design while also providing thermal insulation, fire resistance and interior/exterior finish in one pass, reducing build time, cost and CO2 emissions. Photo Credit: The Pulse of Amserdam, flickr.com, Duplicor

“De Groot & Visser [Gorinchem] designed the system of support points to the building, where they can do the adjustments in the vertical direction and they also designed the seals required for watertightness, because that’s actually their specialty,” says van Uden. “And then we engineered how to connect those seals in the façade element and how to reinforce the attachment points — for example, where local reinforcements were needed.”

“We created 1,200 elements, measuring roughly 4 × 4 meters each,” says Janssen. “Each element has a recess so that you can fit PV [photovoltaic] solar panels on top.” These provide sustainable power without being seen yet are easy to access and maintain. “We had to perform the B Class fire test with these PV panels included. And we also integrated cabling for the solar panels and finished each element with a metallic finish coating. We never use a gel coat.” Elements were supplied to the building site as needed, where they received window glazing before being craned to each floor and installed by two De Groot & Visser installation specialists.

This construction process moved very quickly, says van Uden. “The building process entailed making concrete floors and columns and then you just close those out with these composite façade elements where everything is integrated: structure, insulation and glazing. And that installation goes quite fast because each element is lightweight and easy to handle. You lift it to the concrete floor, adjust it, complete the attachment and watersealing and then move to the next one.” These elements also form the interior surface of the office spaces. “That is what you touch on the inside,” he explains. “There is no other finishing. So, it’s a very efficient, sustainable type of construction.”

Duplicor prepreg is made in-house on a 35-meter-long custom prepreg line using bio-resin and typically, glass fiber reinforcements.

Rolls of Duplicor prepreg, made per each project and structure’s specifications. Note the resin gives a dark brown color even when using glass fiber reinforcements.

Duplicor prepregs are laid up with various core materials — typically recycled PET foam — and then cured via heated press, large vacuum bagging tables or custom molds in ovens.  

Sixteen types of one-piece molded Duplicor composite façade elements were supplied to The Pulse construction site.

Duplicor composite façade elements were crane lifted to each floor and attached by two De Groot & Visser façade installation specialists.

The Van Gendt Halls are five factory buildings from the late 19th century located in central Amsterdam that are being sustainably renovated into an energy-neutral national monument which will house the Drift Museum, as well as a mix of office, commercial and community spaces.

“We have these historically listed buildings in Holland, that have a preservation status,” says Janssen. “Their renovation should maintain the building’s original construction and shape, but also bring the building up to new standards — better insulation for reduced energy consumption and more windows to increase natural light inside, etc. However, the existing structure is typically old wood and thin, rusty steel, so there’s not enough strength left to support this renovation. And yet we cannot take away the beautiful wooden frameworks due to the building’s historical status. So, it creates a real problem.”

“If you don't want to add numerous columns and girders, then you have to keep weight of the new and renovated structures very low,” adds van Uden. “That’s why this project chose to use Duplicor sandwich panels for the whole roof.” A key enabler was that Duplicor could recreate the iconic “steam hoods” on top of these buildings, originally built for the Royal Dutch Factory of Tools and Railway Equipment. “All of the steam and heat from the locomotives and steelwork went out of the building through louvered hut structures on the roof,” explains Janssen. “The construction team had already calculated that wood framed construction weighed too much. But by using lightweight Duplicor composite sandwich panels, they could restore the original shape of these hoods as well as use higher rated thermal insulation, install PV solar panels and other energy-saving systems, and also meet fire resistance requirements.”

Duplicor was used not only for the steam huts, but also for the flat roof panels. “And in between these is a glass window system to bring sunlight inside the building as well,” notes Janssen. “The flat panels we made included a recess for holding all of that glazing and formed the structure to carry all of that load.” Again, the weight of the glass was much more than that of the composite roof panels.

Figure 4. Restoring the roof of Van Gendt Hallen. Duplicor panels enabled restoration of this steam locomotive factory heritage site, including iconic “steam hood” roof structures, while adding windows and solar cells to flat areas without exceeding the original wood and steel skeleton’s load capability. Photo Credit: Braaksma Roos architects (top two images)

The design process began with the architects’ initial designs. “We used those to determine the loads for the various roof structures and how the connections would work,” says van Uden. “We then specified the reinforcements and dimensions for the Duplicor panels and built the FEA [finite element analysis] models to validate and optimize the design. We put all the loads into the FEA models and designed the steam hood connections to the roof structure and also for the flat panel and glazing systems. We then could optimize the laminate sequence, core material and thickness for the Duplicor panels and add reinforcements to support the solar panels, etc.”

The steam hoods were fabricated into modules on the ground, lifted into place with a crane and then assembled into the building structure. Van Uden notes that the wind loads for these were very high, requiring a lot of fasteners to make the connections to resist those loads. The same process was used to complete the flat roof sections. The project has now been completed and was immense, says Janssen. “We renovated almost 13,000 square meters of roofing.”

“I think there is a big market in refurbishing buildings,” says van Uden. “There are a lot of old buildings here in the Netherlands, but also in other countries, that need to be refurbished to comply with new fire regulations and also for increased loading. I think there’s a whole new industry there and composites can help.”

“Designers and engineers now have a solution to recreate the original historical building without being limited by conventional, heavier building materials which prevent them from optimizing the renovation,” says Janssen. “Our solution not only enables performance to current standards but also to meet future energy needs and withstand how our climate is changing. We are providing the thermal protecting skin of a building, and the better you can protect and thermally insulate your building, the better you’re prepared for what is coming in the near future. If we can then also include PV panels on our roofs and façades, even better, because this is needed for the future as well.”

“I also see the potential to refurbish buildings by extending living space outside the building by adding balconies and other structures,” says van Uden. “Those buildings from the 60s are quite cramped, quite small spaces, and designs are evolving to integrate more interior light as well as exterior plants and trees into buildings. So, I think in the whole spectrum of refurbishing, composites can really play an important role.”

These two case histories are exciting, notes Janssen, because they are not the typical high-profile projects for composites where money is no object. Van Uden agrees, “I think we can learn a lot doing those projects, but for a company it’s quite difficult to make that kind of project profitable, because they are always one-offs. Duplicor is very different because it is aimed to provide a more cost-effective composite material for mainstream projects.” Indeed, this is being demonstrated through modular housing — traditionally, a very cost-sensitive sector within construction.

“We have formed two new companies for this,” says Janssen. “We are entering the modular housing market with Qbix, and QSpace is how we started out, with the university housing, but now with Duplicor, we can optimize new designs and make them even more cost-efficient.” He notes that a lot of modular housing companies use steel containers. “But none of them can shape their modules like we can do with composite materials, and that also gives an edge for how we do the construction.”

Flat Duplicor panels are used as walls, roofs and floors in Qbix modular housing.

Qbix is already being used in a project to build 99 housing modules in Limburg for the Netherlands elderly care organization Cicero. “That is being built entirely from 2D building elements — floors, walls and roofs — all made from Duplicor. We use 2D materials made in molds that can actually scale for large building projects — a kind of Lego blocks for new buildings. And another aspect of this approach can be seen in the success of IKEA, where you take home a wardrobe in three flat boxes and assemble the panels together using an easy-to-understand diagram. This is exactly what we are doing with the Qbix modular system. Flat stacked elements are transported with a design grid that you can use to create any building that you imagine.”

“And by using bio-based and recycled materials, the carbon footprint is much better than concrete,” adds van Uden. These are game-changing biocomposites for a bigger scale of building projects, says Janssen. “We are not trying to make art pieces but instead innovate the building industry on a large scale. We have better material properties, use less material and emit less CO2.”

“The building industry right now thinks all of this isn’t possible — that you must compromise on something,” he continues. “But we have worked for years to develop this lightweight, fire-resistant, composite sandwich material that is more cost-effective than the composites we had been using. But it goes further because watersealing, thermal insulation, fire protection and inside/outside finish can all be integrated into one product. And we can mold it to achieve the geometric form that architects want to create or recreate. So, there are no compromises anymore.”

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Bio-based, fire-resistant composites become mainstream | CompositesWorld

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