The Complete Manufacturing Process of Weinuo Carbon Fibre Prepreg

In the realm of composite materials, prepregs are the undisputed 'core players'. Widely employed across aerospace, automotive, and sporting goods sectors, they form the 'backbone' of numerous high-tech products. Today, we take you inside the factory to witness the complete manufacturing process of prepregs – from carbon fibre filaments to finished goods.

Prepreg Manufacturing Process

Step One: Carbon Fibre Filament Tensioning
The story of prepreg begins with the drawing of carbon fibre filaments. Observe these densely packed rolls of carbon fibre filaments, meticulously arranged upon the drawing equipment. Each carbon fibre filament resembles a slender black strand, meticulously aligned by mechanical drawing to prepare for subsequent integration. This stage resembles an army mustering its troops, marshalling dispersed carbon fibres into formation to ensure uniform arrangement throughout subsequent processes. This lays the foundation for the prepreg's performance characteristics.

Step Two: Heat the composite
Upon completion of the carbon fibre filament drawing process, the material proceeds to the heated composite stage. Here, under the influence of heated rollers, the carbon fibre bundles undergo preliminary bonding between layers. The applied heat promotes tighter inter-fibre contact, akin to a 'warm-up' phase, thereby creating optimal conditions for subsequent resin integration. Through this step, the loosely arranged fibre bundles gradually coalesce into continuous fibre layers, taking on the rudimentary form of a 'material'.

Step Three: Roll Forming
Next comes the rolling process. The white rollers act as master moulds, rolling the preliminarily composite carbon fibre layers. This step not only ensures more uniform thickness across the fibre layers but also further eliminates voids between layers, resulting in a denser fibre arrangement. Imagine it like rolling out dough with a rolling pin to achieve uniform thickness. Under the rollers' action, the carbon fibre layers steadily progress towards becoming the "standard prepreg substrate".

Step Four: Resin Impregnation
The most crucial step is now upon us, where the carbon fibre layers undergo a profound fusion with the resin. The resin acts as both an 'adhesive' and an 'enabler', uniformly saturating each carbon fibre filament. You can observe that the pre-impregnated material, after resin impregnation, exhibits a surface with a distinctly high-tech sheen. The addition of resin not only strengthens the bonds between carbon fibre filaments but also endows the pre-impregnated material with exceptional mechanical properties, corrosion resistance, and other 'superpowers', enabling it to perform admirably under various complex operating conditions.

Step Five: Winding the finished product
Having undergone a series of rigorous processes, the prepreg has now taken shape. Neatly wound into a roll, it resembles a scroll awaiting deployment, poised to be dispatched to production lines across the globe. There it will be transformed into the core material for aircraft components, high-performance racing car parts, premium badminton rackets, and other cutting-edge products.

Although the unidirectional and bidirectional processes for prepregs are similar, there are still differences between them.

Core distinction: Fibre structure determines all variations.

1.Unidirectional prepreg: All fibres are arranged parallel in the same direction. Much like a "super-sturdy broom", it can only withstand immense tensile forces along the direction of the broom bristles.

2.Bidirectional prepreg: Fibres are woven into fabric form, typically in the most common plain weave, twill weave, or satin weave. Fibres interlace at both 0° and 90° angles. Much like a piece of canvas, it possesses strength and stability in both directions.

Detailed Comparison: Unidirectional Prepregs vs. Bidirectional Prepregs

Trivia

(1) What can one sheet of prepreg be used for?

(2) How to spot a quality prepreg at a glance?

Examine the surface: The resin should exhibit uniform gloss without any 'white threads' (dry fibres).

Feel the texture: It should not be sticky to the touch at room temperature but becomes tacky when slightly warmed.

Assess the odour: Good resin carries a faint 'rosin' scent; a pungent smell typically indicates inferior curing agents.