A Journey from Thermosetting to Thermoplastic Carbon Fiber UD Prepreg Machine

Since its discovery in the 1950s, carbon fiber-reinforced phenolic prepreg composites have proven indispensable in aerospace and solid rocket engine components that demand high-temperature and ablation-resistant structures.

Over the years, advancements in technology have led to the development of mature thermosetting prepreg processes, including the utilization of autoclave machines and automated fiber placement(AFP) machine.

However, a significant breakthrough came with the emergence of thermoplastic prepreg, offering a reversible process that allows for repeated cycles.

This discovery prompted numerous enterprises to transition into the thermoplastic industry.

Diversity in Carbon Fiber Applications:

Carbon fiber is seldom used in isolation but is rather integrated as a reinforcing material in combination with various resins to create prepreg.

These prepregs, defined as a composite of resin impregnated into continuous fibers and fabrics under strict control conditions, serve as crucial intermediate products in composite material manufacturing.

Varieties of Prepregs:

Depending on the type of resin selected, prepregs can be categorized into thermoplastic and thermosetting, encompassing a range of resins such as epoxy, polyamide, phenolic, bismaleimide resin (BMI), cyanate ester, polysulfone, polyether, and more.

Moreover, prepregs can be classified based on the type of reinforcing material and its structure, resulting in a diverse array of options including carbon fiber, glass fiber, aramid fiber, basalt fiber, boron fiber, unidirectional fiber prepregs, short fiber prepregs, fabric prepregs, and more.

Two-Step Thermoset Carbon Fiber Prepreg Manufacturing Processes:

Many enterprises follow a two-step process to produce thermosetting uni-directional carbon fiber prepregs.

2-step prepreg manufacturing process involves a resin coating machine and a compounding machine.

The resin is heated to a fluid state, coated onto release paper, and subsequently wound to create a resin film.

The film is then combined with continuous unidirectional carbon fiber or fabric through heated and cooled rollers, completing the manufacturing process.

Innovative Powder Impregnation Method:

In contrast, the production process for thermoplastic UD prepreg differs significantly.

Notably, the powder impregnation method is utilized in the production of high-performance unidirectional prepregs.

The method employs electrostatic powder deposition, where resin powder is statically deposited onto fibers and melted at high temperatures, resulting in the formation of prepreg.

The strict requirements on resin powder particle size, ranging from 5-10 μm, highlight the intricacies of this method.

High-Performance Thermoplastic Matrix Materials:

High-performance thermoplastic composite matrix materials, including PEEK, PPS, and PEI, are increasingly used.

The high melt viscosity of these resins makes direct use of melt impregnation challenging.

However, the powder impregnation method overcomes these challenges, making it promising for continuous fiber reinforced thermoplastic composites.

Despite the relatively high cost associated with this method, the resulting prepregs exhibit high gel content stability and excel in impregnating high-performance thermoplastic resins, leading to composites with outstanding comprehensive performance.

Jota Machinery’s Innovation and Expertise:

Jota Machinery, with a decade-long presence in the market, has been a pioneer in continuous glass fiber-reinforced thermoplastic prepreg (CFRT).

Recognizing the evolving market demands, the company successfully developed a production line in 2022 for a 320mm-wide hot-melt thermoplastic carbon fiber ud prepreg machine.

The support resin is below list

1. PA
2. PC
3. PPS
4. PEEK

The advanced carbon fiber prepreg machine boasting a maximum temperature of 450°C, is capable of producing unidirectional tape(UD) with thicknesses ranging from 0.10 to 0.30mm, width 300mm.

The intricate process involves grinding thermoplastic resin into powder, extruding it through a twin-screw extruder, impregnating continuous fibers in a mold, calendaring, and finally cutting and winding after cooling with two pairs of rollers.

The resulting unidirectional prepreg showcases a neat and uniform surface, free from dry yarn phenomena. This innovation positions Jota Machinery at the forefront of advanced prepreg manufacturing technology.