Innovative processes for high-quality carbon components

To produce high-quality composite components, Wethje uses various process and manufacturing technologies which are targeted to the relevant component requirements and planned production quantities.

With the machines and equipment at our disposal, Wethje is also able to produce large components with dimensions up to 12 x 4 m (autoclave technology) and 2.5 x 1.5 m (RTM technology).

Prepreg Autoclav

The manufacturing of components still plays a major role at Wethje. The laminated CFRP- and GFRP-parts are cured under pressure and temperature in the autoclave.

In the autoclave process, prefabricated prepreg materials are laminated layer by layer in a tool. The autoclave manufacturing requires a lot of manual work. When the layup is finished, the part is cured under vacuum in the autoclave with the desired parameters.

The autoclave production has many applications. High Class A requirements of the automotive industry can be fulfilled with this process. Autoclave technology is also indispensable for structural components and in prototype construction. At Wethje, autoclaves in sizes from 0.8m x 1.0m to 4.5m x 15m (diameter x length) are available for production.

Prepreg Out of Autoclav

The OOA (Out OAutoclave) is an alternative to the conventional prepreg autoclave technology. The composites are cured without an autoclave.

The tool is prepared with the desired prepreg materials and layer stacks. Many different materials and layups can be realized.

In the Out Of Autoclave process, the tool is located in one station, where it can be heated, evacuated and pressurized. The laminated material can thus be cured under the optimal parameters for each application.

With the Out Of Autoclave technology it’s possible to produce composites with high qualitative requirements without an autoclave.


In the RTM process (Resin Transfer Molding) dry preformed layer stacks are placed in a heated press tool and a resin-hardener-mixture is injected.

In contrast to the SMC and PCM processes, RTM uses dry carbon fiber or glass fiber mats, which are preformed into the desired three-dimensional geometry and placed in the preheated press tool.

The resin-hardener-mixture is injected in the closed tool and saturates the inserted fibers before it cures under temperature.

RTM with wax core

The RTM technology also offers the possibility to produce hollow parts. For this purpose a preformed wax core is positioned in the press tool as a core in the middle of the layer stacks. After the injecting and curing the wax core will be melted out in a defined tempering process and can be used again.




During the SMC (Sheet Molding Compound) pressing prefabricated SMC panels are molded in a desired component shape using a heated pressing tool. The SMC plates are produced in-house at Wethje by Mitsubishi on its own SMC plant. The size of the SMC panels isn’t defined by the component- and toolsize like PCM, but by the weight/volume of the desired component. After placing the SMC material in the press and the pressing tool closes, the panel dispersed fluently throughout the entire tool. The resin/hardener impregnated carbon material reacts with the temperature of the mold and cures to a finished SMC component within a few minutes.


During the PCM (Prepreg Compression Molding) process prefabricated preforms (performed CFRP-prepreg layers) are pressed into the respective component shape in a press tool.

The prepregs are cutted in a desired component size and performed in a component shape. In the PCM process, a wide variety of layer structures an materials are possible.

The created preform is is now cured under pressure in the PCM process step in a press using a heated press tool.

After a few minutes, the finished PCM component can be demolded. The PCM technology is therefore particularly suitable for high-volume components that can be produced in a short time. PCM can also be used to produce CFRP visible components.


  • In-house paint shop with an area of around 400 m²
  • 22 employees
  • Painting preparation (150 m²)
  • Painting area (130 m²)
  • Water-based paints and paints containing solvents, depending on our customers’ requirements
  • Finish and QA area (120 m²)

In the area of visible carbon, we supply renowned manufacturers from the automotive, motorcycle and aerospace industry.

Testing equipment

Light Tunnel

  • Dimensions: 4500 mm x 3200 mm
  • State-of-the-art LED light technology
  • Programming according to customer-specific brightness values

Mitutoyo 3D Coordinate Measurement Machine

  • Measurement area: X 1200 mm / Y 2000 mm / Z 1000 mm
  • Workpiece weight: max. 2000 kg

Wenzel 3D Coordinate Measurement Machine

  • Measurement areaX 3500 mm / Y 1300 mm / Z 1800 mm
  • Workpiece weight: max. 3400 kg

FARO Measuring Poor

FARO Edge Model 14000 (Volume of work 2400 mm) with Laser Line Probe

Software: PolyWorks

Faro-Messarm Wethje GmbH