Toray and Takagi Seiko Corp. (Toyama, Japan) molded this large model member with a CFRF core and a CFRP skin.
Photo Credit: Toray Industries Inc.

Toray develops rapid integrated press molding technology for CFRP mobility components

The process and material innovation simultaneously shapes, molds, thermosets and bonds the core and skin in the same mold, achieving this 10 times faster than conventional autoclave molding setups.

Toray Industries Inc. (Tokyo, Japan) has developed a rapid integrated press molding technology for carbon fiber-reinforced plastic (CFRP) mobility components.
This material sandwiches a light, porous short carbon fiber-reinforced foam (CFRF) core (fibers 5-10 millimeters long) with a specially formulated fast cure-type thermoset prepreg.

A combination of process- and material-based innovation, the technology reportedly makes it possible to press mold such components — a car roof, for example — 10 times faster than a conventional autoclave molding setup. Toray obtained findings for this technological advancement under the New Energy and Industrial Technology Development Organization’s (NEDO) Research and Development of Innovative Structural Materials project.

CFRP members typically sandwich urethane foam cores with thermoset prepreg skins. Common applications for these light and rigid structures are large panels for aircraft, automobiles, ships and infrastructure. Some manufacturers have pushed for shorter manufacturing times to optimally bond the core after shaping it to the skin.
Toray confirmed that the skin-core interface did not delaminate and that impact absorption is excellent.

Toray’s new rapid integrated molding technology makes it possible to fabricate large panels in a single shot. Through heat and pressure, the approach simultaneously shapes, thermosets and molds, and bonds the core and skin in the same mold. Ultimately, synchronizing CFRF’s expansion with the prepreg’s curing timing is significantly faster than with conventional processes, Toray reports. The prepreg’s thermoset resin penetrates the porous CFRF to bond the skin and core materials without using adhesives, for a highly reliable bonding structure. Toray’s technology may pave the way for quick production of large CFRP components.

According to the company, CFRF offers significantly better strength, elastic modulus and impact resistance than conventional core materials. Its low specific gravity range of 0.2 to 0.4 can enhance performance and lighten sandwich structures. Toray demonstrated its concept by using a pressing machine to create a large automotive roof panel (1.2 meters long, 1.2 meters wide and 2.3 millimeters thick) in just five minutes. Core thickness before molding was 1.7 millimeters, and 0.8 millimeter after molding. The company assessed rigidity, coatability, sound insulation properties and other practical aspects for automotive production. In vital drop-weight impact tests, Toray confirmed that the skin-core interface did not delaminate and that impact absorption is excellent.

Read: Plant tour: Avel Robotics, Lorient, France

Generally, Toray says it is looking to replace any panel component that its technology can be applied to, taking advantage of the innovation’s ability to create lightweight parts with high rigidity that also excel in impulsivity, sound and heat insulation.

Toray says it will keep pursuing R&D to accelerate the application of this technology to electrified vehicle parts, for which lightness and fast production are vital. The company also looks to cultivate such emerging transportation modalities as urban air mobility (UAM) and drones that benefit from functional, lightweight materials.

The technology is still in its development stage, but the company aims to commercialize it by 2030, offering a materials-based technology and a process-based

#composites #Toray #CFRP

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Dear Colleagues!

There are 12 days left until the start of the 15th Composite-Expo 2023 exhibition!

On the official website of the event, the current floor plan of the exhibition and the preliminary list of exhibitors have been updated.
There is still time to apply and take part as an exhibitor!

The exhibition will be held from 28 to 30 March in pavilion 1 of the Expocentre Fairgrounds.

You can get a free invitation ticket to Composite-Expo 2023 after registering on the website.

See you at the exhibition!

Dear friends!

Tomorrow, March 28, the main event of the composite industry in Russia, the 15th international exhibition Composite-Expo 2023, starts. Exhibitors and visitors will have three days of active communication at the stands and events of the business program. Venue: Pavilion 1, Expocentre, Moscow.

Exhibition opening hours:
March 28 and 29 - from 10.00 to 18.00
March 30 - from 10.00 to 16.00

• get an invitation card

• venue

This year, as part of the business program of the exhibition, there will be:

March 28-29: The 10th Anniversary Forum "Composites Without Borders" will be held for the first time as part of the exhibition

March 29: Fourth scientific and practical conference "Practical aspects of the use of composite materials in various industries" | conference program

March 28: Round table "Protection of intellectual property of manufacturers of composite materials" (visiting is limited, by prior registration) | roundtable topics

• exhibitors catalogue

• floor plan

See you at the exhibition and business program events!

#composites #CompositeExpo2023 #CompositeExpo #ExhibitionCompositeExpo

Dear participants, visitors, colleagues!

Three busy working days of the Composite-Expo 2023 and Polyurethanex 2023 exhibitions flew by unnoticed.

We thank all the regular exhibitors of our events, as well as the companies that decided to participate in exhibitions for the first time in today's difficult conditions!

We thank the visitors for their active interest in the exhibitions and the extensive business program within their framework!

The final information on the events (press releases, photos, feedback from participants, statistics, etc.) will be posted on the official websites in the near future.

The 16th International Exhibition Composite-Expo 2024 and the 15th International Exhibition Polyurethanex 2024 will be held from March 26 to 28.

Preliminary booking of booths is already open!

Anisoprint expands global presence with Shanghai office

New office located in the Additive Manufacturing Technology Centre enables Anisoprint’s expansion into the Asia-Pacific region.

Anisoprint (Esch-sur-Alzette, Luxembourg), a provider of composite 3D printing solutions, has announced the opening of a new office in Shanghai, China. The office is located in the Additive Manufacturing Technology Centre (AMTC), a state-of-the-art facility that provides access to cutting-edge 3D printing technologies and equipment.

The new Shanghai office will serve as a hub for Anisoprint’s expansion in the Asia-Pacific region, providing local customers with access to its 3D printing solutions and services. The office will also support the company’s existing partners in the region and facilitate the development of new partnerships with companies interested in leveraging the power of 3D printing to innovate and optimize their operations. The new location brings with it novel opportunities for R&D activities and further technology development with the support of local institutions.

“We are excited to open our new office in Shanghai and to be located in the AMTC 3D Printing Center,” Fedor Antonov, CEO of Anisoprint, says. “This move represents a significant milestone for our company, as we continue to expand our global presence and bring our cutting-edge 3D printing technologies to customers around the world. We look forward to working with our partners in the region to unlock new opportunities and drive innovation.”

AMTC is a world-class facility that provides access to the latest 3D printing technologies, materials and expertise. The center is dedicated to driving innovation and helping companies explore the full potential of 3D printing. AMTC welcomes other 3D printing companies like BigRep, HP and Intamsys. The companies’ expertise aligns with a focus on innovation, sustainability and aim to drive the adoption of 3D printing in key industries.

Photo Credit: Anisoprint

#composites #Anisoprint #AMTC

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Repairable composites based on epoxy vitrimer for aeronautics

The AIRPOXY project proposes a new generation of intrinsically-repairable composite materials based on an epoxy vitrimer to reduce production and MRO costs in the aeronautics industry. Specifically, this article presents a very simple and cost-effective method for repairing a typical transverse stiffener. This article has been published in the JEC Composites Magazine N°148.
Due to their inherent complex damage behaviour, structural repair is a major challenge for advanced composites in the aerospace industry. Various defects can be initiated during manufacturing and in-service. For example, delaminations in the bending radii of the stiffeners can occur when demoulding the part. Often, these delaminations cannot be repaired with existing technologies, which leads to a high scrap rate, up to 20- 30% depending on the part’s complexity.
Within the AIRPOXY EU-funded project, a very simple and cost-effective method was developed to repair this type of delamination. This was made possible by a family of vitrimer epoxy resins developed and patented by Cidetec that present reversible or dynamic aromatic disulphide bonds. These dynamic bonds provide a series of smart properties, creating a new generation of composite materials that retain their high performance, in terms of easy fibre impregnation and overall stability, while showing unprecedented new features once the material is completely cured, such as re-processability, reparability and recyclability. This is why they are called “3R composites”.

Thus, delaminations in 3R composites can be repaired by simply applying heat and pressure to the damaged area (Figure 1).

As the global aim of AIRPOXY is to reduce the production and maintenance costs of composite parts in the aeronautic sector, the project’s scope exceeded the study of repairability and also included the thermoforming and bonding capacity of 3R composites. Figure 2 summarizes the project’s concept and its main specific objectives.
The AIRPOXY project is conducted by a consortium made up of the resin developers (Cidetec), key technology providers (Leibniz- IVW as an expert in thermoplastic composites thermoforming and welding, Eurecat as an expert in RTM and LCA/LCC/HHRA analysis, Coexpair as an SQRTM process expert, the University of Ioannina as an expert in structural health monitoring techniques and Altair as an expert in process simulation software), and aircraft component manufacturers (EireComposites, IDEC and Sonaca) together with standardization experts (UNE) and an aeronautics consultancy firm (Arttic).

The 3R composite and its repair method were validated through the manufacturing of a transverse stiffener (TS) demonstrator using the RTM process, which was damaged in a controlled manner and repaired using a specific tool to apply localized pressure and heat. The main steps are described next.

Design and production of the transverse stiffener

As a first step, Cidetec formulated the 3R epoxy resin with a Tg of 170°C, taking into account three main goals: (1) producing a vitrimer resin – therefore reprocessable, repairable and recyclable; (2) meeting the aeronautical sector’s specifications in terms of mechanical and thermal properties; and (3) being suitable for the RTM process in terms of rheology and curing kinetics.

To meet the first goal, the vitrimer epoxy resin was formulated based on a dynamic disulphide exchange mechanism, which seems to be the most promising mechanism for the aeronautics industry since the operational Tg ranges of the resulting polymers are almost in line with those of current thermoset materials. The hardener selected was 4-aminophenyl disulphide (4-AFD), which is commercially available for future industrialization. To fulfil the second and third goals, the first part of the resin was formulated with a mixture of tetraglycidyl-4,4´ methylene dianiline (TGMDA) and bisphenol F diglycidyl ether (BFDGE). Combining these two monomers makes it possible to achieve the mechanical and thermal properties required by the aeronautics industry, as well as the rheology and curing kinetics needed for the RTM process.

Both the 3R resin and the 3R composite were extensively characterized to verify that the three objectives had been met. Once the 3R resin was developed, the transverse stiffener demonstrator was designed and produced by IDEC.

The transverse stiffener is a structural element with a complex geometry (combining an omega and a transverse shape, see Figure 3) about 420 mm long. It was made by the RTM process using the project materials, the 3R resin and an intermediate-modulus carbon fibre (5-harness satin woven material and unidirectional fabric). Additionally, a peel ply was added on one of the surfaces to achieve the roughness needed to bond the rest of the sub-components (skin and longitudinal stiffener).

The mould used to manufacture the transverse stiffener was divided into several parts (see Figure 4), some of which were used to overmould the carbon fibre layers. The mould was closed with screws and heated in an oven, a vacuum was applied and the 3R resin was injected under pressure (1 to 6 bars).

Then, the 3R resin was cured in a twostep cycle (60 min. at 130°C and 30 min. at 180°C) and the transverse stiffener was demoulded.

Finally, the part was trimmed (see Figure 5) and inspected by ultrasonic testing (UT).

Defining the best repair strategy

In parallel, a study at the specimen level was performed by Cidetec and Eurecat to define the most suitable repair parameters (pressure- temperature-time) and the best way to apply them on the specimen. Two solutions were considered: 1) using an autoclave, which made it possible to apply pressures of up to 7 bars and generalized heating over the entire damaged piece; and 2) using a press to apply heating and higher pressure locally, just on the damaged area.

First, delaminations were generated by impacting 3R laminate specimens in a controlled way, using an impactor tower and a hemispherical tip 16 mm in diameter to create a damage of around 750 mm². The damages were identified by ultrasonic techniques. Next, the specimens were repaired in an autoclave or press using different pressure-temperature-time conditions. Afterwards, the specimens were inspected again using ultrasonic techniques. In the cases where the results were satisfactory, the repaired areas were subjected to a microscopic analysis to confirm that they were free of defects. Interlaminar shear strength (ILSS) specimens were also extracted from the repaired areas and tested.

The best results were obtained using the press, heating the area to be repaired to 210°C and locally applying 20 bars of pressure for 20 minutes. Figure 6 compares the microscopic analysis of an impacted area (many delaminations can be identified) and a repaired area (the delaminations have disappeared), while Figure 7 compares the ILSS test results of two specimens; the first one from a reference panel and the second one from an impacted area after repair. The values showed that, although there is a slight loss in strength (21%), the elastic modulus remains unaffected.

Damaging and repairing the stiffener