The Composite preforming Process

Composite parts made from fiber and epoxy resin are highly sophisticated building materials for all kinds of high-performance components ranging from aerospace applications to automotive parts. The unique combination of high tensile strength and low weight, which fiber-reinforced composites offer to modern engineering, requires equally sophisticated manufacturing processes. Preforming before completion of the final part is perhaps the most crucial step during the entire procedure. It is no wonder then, that this step also benefits most from technological advances such as the patented Compositence system.

Automation in the Manufacture of preformed Carbon Fiber-reinforced Composites

When creating complex preforms, many manufacturers still rely on manual layup. However, with the inclusion of robotics into the manufacturing process, the benefits of automation have become increasingly evident:

  • Quick turnout of high production volumes
  • Minimized waste of fabrication materials
  • Low probability of human error
  • Software-optimized efficient planning

Of course, some companies still prefer preforming by hand or semi-automated for its advantages. Most notably, manual work is often considered to allow for easier manufacture of highly complex composite shapes. However, the process is more material, time and labor intensive than automated preforming, making it less viable economically, particularly at high production volumes. Additionally, the patented Compositence manufacturing technology with its edge fixation system is able to preform even the most complex shapes, making manual layup ultimately entirely redundant.

Two variants of preforming Procedures

A preform ready for finalization can be essentially created in two different ways:

The traditional method is derived from conventional manufacturing techniques. Carbon fiber rovings are first woven into non-crimp fabric sheets, which are then cut into shape, stacked for layup and turned into a preform by injecting and pre-curing the resin binder. Alternatively, prepreg materials may be used to make the step of epoxy injection obsolete. This procedure can be partially automated by employing machines for the weaving and cutting steps, though layup by hand is usually still necessary.

Using patented automated Compositence technology, a preform can be easily shaped without creating the amounts of waste material usually produced when cutting woven fabrics into shape.

Machine-supported preform manufacturing methods such as Automated Fiber Placement (AFP) or filament winding, on the other hand, can eliminate the textile weaving, cutting and manual layup steps for preforming altogether. Both of these preforming techniques rely on computer-controlled machines to lay or weave either pure carbon rovings or prepreg composite materials directly into the shape desired for the preformed product.

Computer-assisted Preform Production

Aside from controlling the robotics technology employed for the fabrication itself, specialized software is widely used for form planning as well. Such software enables designing shapes to be used for composite products and later simulating the mechanical properties of the finished components, depending on the composites used.

The highly sophisticated Compositence design software can determine the ideal approach to preforming procedures, even for complex shapes that usually require molding of the component into the final form after preforming. The software is a highly sophisticated tool which allows for planning, simulating, optimizing and preforming directly from the data thus gained. In combination with Compositence fiber placement machinery, it minimizes both the time and material required for preforming.

Proper Procedure for any preformed Component

Carbon composites require a plethora of production steps in order to fit the final form they have been created for. When creating such a part, preforming is a fundamentally necessary step in ensuring great quality for the finalized component – leading to additional costs in labor and material. However, modern Compositence fabrication technology and software can reduce the time, effort and material resources required for planning and producing preformed parts significantly.