LINE CONCEPTS FOR THE PROCESSING OF CARBON FIBERS AND RECYCLED CARBON FIBERS

The role of carbon in industry continues to increase - automotive construction, mechanical engineering, medical technology as well as the pharmaceutical industry and aviation are no longer conceivable without carbon fibers. Carbon has a very high stability and is, for example, four times more resilient than aluminum. Carbon is not only extremely light but can also be used in a wide range of applications. Carbon can be shaped in almost any way and is corrosion-free. Due to its vibration resistance, it can absorb large amounts of energy in the event of a collision and is therefore particularly valued in the automotive industry and mechanical engineering. In automotive design, many components that were previously made of metal can be replaced by fiber composites. In this way, vehicles become lighter and can thus travel further distances or reach higher speeds with less energy input.

Extremely lightweight and durable components can be manufactured from carbon fiber reinforced plastics (CFRP) as well as from composites with natural fibers. For this purpose, AUTEFA Solutions offers a unique production line for customer testing. We also provide our line to produce small series. The line starts with machines for fiber opening as well as machines for web forming. Here we offer different possibilities in terms of fiber orientation and web weight. The Stylus Variliptic Needle Loom is available for web bonding. Together with our customers, we develop products for a wide range of applications so that carbon fibers but also glass and aramid fibers, can be recycled and processed economically.

In the recycling of carbon fibers, a distinction must first be made according to the matrix content of the material to be recycled. In the case of recyclable materials with a matrix (prepreg, cured components), the matrix must be removed, for example by pyrolysis. Dry, resin-free waste can be processed directly at recycling plants. The recycled fibers can be used to produce a variety of nonwovens.

Lines for fiber opening and fiber blending are flexibly projected and adapted to the fibers to be processed as well as to the nonwoven product. This guarantees the highest nonwoven quality and process reliability.

AUTEFA Solutions' aerodynamic carding machines operate according to the aerodynamic principle, whereby a three-dimensional fiber orientation and absolute entanglement of the fibers (randomization) is achieved. Randomization is the basis for isotropic nonwoven strength. Airlay lines, i.e., lines with randomized nonwoven carding, are characterized by highest product quality, economy, and reliability. During the process, the material is opened down to the individual fiber; this allows high flexibility in terms of fiber selection. Due to the modular design, the line can be customized to specific product requirements.

A core machine in the drylaid process is the carding machine. The modular machine concept of AUTEFA Solutions offers different carding types, which are optimally designed for the specific applications. All carding machines are characterized by flexibility, high production speeds and process efficiency. AUTEFA Solutions carbon card ensures very good fiber separation with unidirectional alignment.

Weight accuracy in lapped and bonded webs is the most important quality feature for a nonwoven installation. AUTEFA Solutions´ Crosslappers of the Topliner series are characterized by high infeed speeds and precise weight distribution. They take up the carded web coming from the carding machine with constant speed and gently place it on the delivery belt. The carding machine for carbon fibers can also be combined with the Crosslapper of the Topliner series to influence the fiber orientation, surface weight and width of the web.

Needle looms or needle punching machines are essential in the production of nonwoven fabrics. Nonwovens are mechanically bonded by needling. The needles vertically punch in and out of the material. In this process, the machine transports the material, needles with small barbs take the material with them as they move up and down, bonding the fibers together. The Stylus Needle Loom Variliptic provides mechanical web bonding and offers the possibility to process 100% carbon fibers.

AUTEFA Solutions ovens are designed for thermal bonding of nonwovens and likewise for drying of nonwovens. The AUTEFA Solutions HiPerTherm belt dryers are characterized by a constant air flow as well as the precisely adjustable and consistent temperature distribution. The optimal conditions here allow on the one hand the flexible production of voluminous products with minimum densities or on the other hand the production of high-density end products. The design as dryer for nonwoven thermobonding enables the processing of natural, recycled, glass and other mineral fibers up to synthetic fibers. By adding a thermoplastic fiber, thermal bonding creates multifunctional Nonwovens.