Prepreg Resin Coating Machine

The prepreg resin coating machine is a key piece of equipment in the production of thermoset carbon fiber composites. It plays a crucial role in the two-step carbon fiber prepreg manufacturing process, which includes “filmer” preparation and compounding.

The resin coating machine is specifically designed to transform high-performance resins such as epoxy (EP), bismaleimide (BMI), and cyanate ester (CE) into a resin-coated film. This is achieved through a hot-melt processing method, where the resin is applied to release paper to create the final resin film for further production stages.

In the prepreg manufacturing industry, two primary types of resins are commonly used: solvent-based resins and solid resins. Each type requires distinct processing techniques due to their differing properties, and the choice of resin significantly influences the coating method and equipment used.

Solvent-based resins, which are dissolved in a solvent to facilitate easier application, require careful handling of evaporation and curing processes, while solid resins, often used in hot-melt systems, are more viscous and require precise temperature control for optimal results.

At Jota Machinery, we specialize in provide a wide range solution of prepreg materials, with a focus on high-performance solutions from immpregnation to slitting & traverse spooling, for the aerospace industry. In addition to manufacturing Phenolic-based prepregs, we mainly utilize the advanced 1270mm width hot-melt coater.

The coater machine is specifically designed for the high-precision production of unidirectional (UD) and fabric prepreg tapes, which are essential in aerospace applications that demand exceptional strength-to-weight ratios and reliability.

The prepreg resin coating machine consists of 5 key operational stations: the unwinder stands, hot-melt unit, coating unit, thickness measurement and control unit, and the PE film unwinder and rewinder. These integrated components work seamlessly together to ensure precise and efficient resin application, maintaining high standards of quality throughout the production process.

Unwinder stand

The 1st unwinder stand is designed to hold the raw release paper securely in place. It is equipped with an air-expanding shaft that adheres to the international standard 3-inch (76mm) size.

• The max unwinder diameter:800mm
• The max weight can bear:1100kgs
• Max torque：400N
• Paper splicing table:vacuum suction cup type

Additionally, the unwinder stand is fitted with an advanced ultrasonic web guide system, providing precise alignment with a tolerance of ±1mm. This system ensures that the release paper remains consistently centered throughout the unwinding process, maintaining optimal alignment for subsequent operations.

Hot melt unit and coating unit

The hot-melt unit and coating station are integrated into a single operational unit, working seamlessly together.

The melting process is fully electrically controlled, with the temperature set and monitored via the HMI (Human-Machine Interface) system, ensuring precise control and consistency. For solid resin systems, we offer a dual stage melting process, including preliminary and fine melting stages.

The unit consists of a robust bracket and heating plate. Initially, the solid resin is melted on the bracket, after which it undergoes a secondary melting process on the heating plate. Finally, the molten resin flows into the coating roller gap for uniform application. This dual stage melting method is a proprietary process and is patented by our company.

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The coating system consists of 2 pcs φ345mm x 1330mm steel rollers and 1 pc φ300mm x 1300mm rubber roller. The two steel rollers operate in a reverse coating process, replacing the traditional doctor blade method. This innovative approach ensures more precise and efficient coating application.

The coating thickness is meticulously controlled by adjusting the gap between the rollers. The gap settings are continuously monitored and displayed in real-time on the touch screen, allowing for high-precision coating to meet exacting standards.

Thickness measurement unit

To produce high-grade aerospace carbon fiber prepreg, precise control over the coating thickness is critical. While operating the coater is relatively straightforward for each operator, maintaining consistent coating thickness presents a significant challenge.

To ensure precise monitoring and control of the coating thickness during production, we have equipped the system with the advanced infrared NDC thickness measurement technology from the United States. The coating thickness is continuously monitored and displayed on an independent touch screen, allowing for real-time adjustments to achieve optimal prepreg quality.

PE film unwinder and filmer rewinder

The PE film unwinder stand serves as the second unwinder station, designed to hold the surface film that protects the resin film (also known as “filmer”) from dust and contaminants during the production process. This unwinder stand features a dual-station setup to ensure continuous, non-stop production of the filmer.

Once coated, the filmer is ultimately rewound onto the final rewinding shaft. The rewinding meter is displayed in real-time on the main touch screen, providing operators with immediate visibility of the process. The rewinding speed is dynamically calculated by the PLC, adjusting according to the coating speed to maintain optimal tension throughout the process.

Our hot-melt coating process ensures uniform resin distribution and excellent impregnation of the fibers, resulting in high-quality prepregs that meet the stringent requirements of the aerospace sector.

The method is particularly beneficial for producing aerospace-grade UD and fabric prepreg tapes, which are used in critical applications such as structural components, fuselage, and wing assemblies. The precision and control offered by the 1270mm hot-melt coater ensure consistency in resin content and optimal curing properties, making it an ideal solution for producing high-grade aerospace prepregs.

We have been involved in the advanced composite materials industry since 2001, starting in Ruian City, Zhejiang Province. By 2025, we have developed a comprehensive range of solutions for both thermoplastic and thermoset prepregs. If you are seeking a 1300mm hot-melt prepreg machine, please do not hesitate to contact us.