Automotive Applications of Thermoset Composites

The current global trend for increasing mobility while minimizing carbon dioxide emissions to support sustainability has led to a rise in safety requirements.

Due to their inherent structural strength a number of composite materials are being used by Toray Advanced Composites in its Protecting People mission.

Driving the Change

The Toray Cetex from Toray Advanced Composites has become a benchmark for high quality engineered thermoplastic composite materials in the aerospace industry. The polymer can be altered in order to meet the needs of various applications.

In order to cater for the huge volume requirements of the automotive industry, the current batch production processes that have been successfully delivering high quality products consistently need to be converted into continuous processes.  The value chains established by Toray  in the thermoplastic composites market can be leveraged for applications in the automotive industry as well, where cost leadership is an important factor (Figure 1).

Figure 1. Toray offers a range of composite solutions for the automotive industry.

Lightweight Advanced Composites

Toray Advanced Composites is among the global market leaders in the development and manufacturing of advanced composite materials. These materials are robust, energy-efficient and sustainable solutions for many industrial applications since they are lightweight and hence their fuel consumption is minimal. Toray has specialized expert teams working in each of its advanced composites production sites in the United Kingdom, Canada, the United States and the Netherlands.

Extended Application Areas

Backed by more than three decades of experience and lineage, the scope of applications for the Toray Cetex and thermoset thermoplastics has diversified considerably. Some of the current applications include side beams, front beams, wheels and underbody panels and pedals (Figure 2). The principal component of the entire monocoque of the Alfa Romeo 4C chassis is the thermoset E700 series carbon fiber prepreg from Toray. Toray has tied up with the Adler Group for product development and investment in a production capacity. The central passenger cell provides a very strong and safe base structure while minimising the vehicle’s weight.

Figure 2. Toray thermoset and Toray Cetex^® thermoplastic materials have a diverse and proven range of application areas.

Collaborative Strategy

Collaboration between research institutes, suppliers and customers is common in the advanced composites market. New applications are mostly the result of such collaborations.

Toray’s own collaborative strategy is of great benefit to its customers. As a result of Toray’s powerful technological partnerships, a number of their advanced composite solutions have been weaved into the automotive supply chain. The advanced tape and fiber placement with TPRC (The Netherlands) and industrial-scale parts manufacture and process development with the National Composites Centre (UK) are two such collaborations.

Thermoplastic Composites

The various forms Toray thermoplastics are available in include UD tapes or organo sheets, and prepregs. These forms can be used in various manufacturing stages and for designing parts. The continuous fiber-reinforced thermoplastic Toray CFRT is another product that can be pre-consolidated and customized as per the needs of customers.

Key Advantages

The advantages of using thermoplastic composites include short cycle times, quick installation, recyclability, weldability, and elimination of freezer storage.

Key Processing Technologies for Proven and Reliable Volume Part Manufacturing

Some of the technologies used in the manufacturing of volume parts include over-molding, advanced tale placement, compression molding or thermoforming, tubular winding, in-situ or autoclave processing, and variable in-molded composite sandwich.

Toray Cetex^® UD Tapes

Toray Cetex^® UD tapes are made up of glass fiber and carbon fiber that is reinforced with thermoplastic polymers such that the fiber volume content ranges between 45 and 55%, and the thickness from 0.15 to 0.3 mm. These tapes can be used in the manufacture of automated parts and tubular windings. The various resin types and corresponding processing temperatures are listed in Table 1.

Table 1. Resin Types and processing temperatures.

Toray Cetex^® Organo Sheets

Toray Cetex^® organo sheets are composed of carbon and glass fiber reinforced thermoplastic (RTL), also known as organo sheets. The orientation of fiber and fabric architecture can be modified as per the needs of particular applications. The thickness of the laminates varies from 0.5 to 20 mm. These sheets may be used on various volume applications like structural, load-bearing pillars, chassis, and other structural interior parts. Pre-cut blanks, shaped and tapered materials can be derived from these organo sheets. Table 2 lists the different combinations and the corresponding processing temperatures.

Table 2. Various combinations and the corresponding processing temperatures.

Thermoset Composites

The degree of impregnation and resin content as per the unique processing and handling requirements of each application can be achieved by Toray’s thermoset composites using the film impregnation and direct impregnation techniques (Figure 3). Apart from using different types of proprietary resin systems ranging from high-temperature cyanate esters and BMIs to toughened epoxies, other materials like glass, carbon, and aramid based reinforcements are also used. The following five types of thermoset prepregs are manufactured:

Figure 3. Toray thermoset composites utilize both film impregnation and direct impregnation controlling the resin content as well as the degree of impregnation to meet unique handling and processing requirements for each customer.

Low Temperature and Curing Properties

Toray's thermoset composites are epoxy-based prepregs that enable quick prototyping. The properties of these prepregs are listed in Table 3.

Table 3. Temperature properties of Epoxy Prepregs.

Medium Temperature Curing Prepregs

These prepregs are mostly used in making structural components. A cosmetic high clarity prepreg is the latest addition of Toray’s prepreg offerings. The properties of these prepregs are listed in Table 4.

Table 4. Temperature characteristics of Medium Temperature Curing Prepregs.

Out-of-Autoclave Curing Prepregs

The out-of-autoclave curing prepregs are cured by vacuum bagging, which avoids the use of high-pressure autoclaves and enhances the flexibility in manufacturing. A substantial amount of energy is saved during processing, thanks to the use of less expensive tooling. The properties of these prepregs are listed in Table 5.

Table 5. Temperature characteristics of Out-of-Autoclave Curing Prepregs.

High-Temperature Curing Prepregs

High temperature curing prepregs are made of cyanate esters, and are used in applications that operate at temperatures higher than 300 °C. The characteristics of this type prepregs are listed in Table 6.

Table 6. Temperature characteristics of high temperature curing prepregs.

Toray AmberTool^® Prepregs

The services offered by Toray cater to various tooling composite requirements ranging from a pattern and technical to material support. All the molded and machined tooling applications that are based on Toray’s product solutions are highly accurate and precise. Table 7 lists the temperature characteristics of Toray AmberTool^® prepregs.

Table 7. Temperature characteristics of AmberTool Prepregs.

This information has been sourced, reviewed and adapted from materials provided by Toray Advanced Composites.

For more information on this source, please visit Toray Advanced Composites.