Advancing Precision and Efficiency: The Innovations in Narrow Prepreg Slitting Machine and Spooling Processes

Prepreg refers to a specialized form of carbon fiber fabric or tow that has been pre-impregnated with epoxy resin.

This meticulous process involves saturating the fabric with resin to ensure uniform distribution and optimal wetting of the fibers.

The prepreg is then partially cured, reaching a semi-solid state known as “B-staged,” which allows for storage at low temperatures without complete curing.

The semi-solid state facilitates easier handling, cutting, and layup procedures during the manufacturing process.

To meet the need for customized widths of prepreg, Jota Machinery proudly introduces an innovative solution: the spooled narrow prepreg tow in automated fiber placement (AFP).

Our advanced technology provides automated precision in placing narrow prepreg tows, enhancing manufacturing efficiency and accuracy.

Pre-slitting, slitting, and spooling are critical stages in the composites industry for processing materials like carbon fibers.

However, these processes often result in excess rewinding material, which adds burden and waste to the production line.

Addressing the issue of redundant rewinding is crucial for improving production efficiency and reducing costs.

During the pre-slitting stage, carbon fiber-reinforced polymer (CFRP) is cut according to specific size requirements for further processing.

The slitting process cuts the pre-cut material into sizes ranging from 30mm to 180mm, depending on the product requirements.

The traverse spooling process then rolls up the cut material, with a maximum winding height of 300mm, for storage or future use.

However, redundant rewinding often occurs due to dimensional changes in the production process, material loss, or design variations.

These rewinds take up valuable production space, increase storage and handling costs, and negatively impact line efficiency.

To address this issue, there is a growing focus on treating excess rewinding in pre-slitting, slitting, and spooling equipment.

Advanced control systems and precise cutting technology are being introduced to minimize the generation of redundant rewinding and ensure efficient cutting and winding processes.

Some equipment also incorporates intelligent sensing and automation functions, allowing automatic adjustment of cutting and winding parameters based on actual requirements, minimizing waste and rewinding.

By optimizing the pre-slitting, slitting, and traverse spooling processes, effective management of excess rewinding enhances production line efficiency, reduces costs, and minimizes resource waste.

This aspect is crucial for the sustainability and economic viability of the composites industry, driving companies to continuously seek innovation and improvements in pre-slitting, slitting, and winding processes.

The narrow with prepreg slitting machine is a specialized piece of equipment designed for high-precision slitting of monofilament impregnated or multifilament impregnated prepregs and continuous fiber-reinforced unidirectional prepreg tapes.

Its primary function is to cut carbon fiber-reinforced epoxy fiber prepreg (CF/EP) or fiber-reinforced unidirectional prepreg tape into narrow widths according to predetermined specifications.

Commonly used widths include multiples of 3.175mm, 6.35mm, and 12.7mm.

These narrow prepregs find applications in the second stage of reinforced thermoplastic pipe (RTP pipeline) manufacturing for winding  equipment.

The prepreg slitting traverse  spooling machine incorporates advanced cutting technology and a sophisticated control system to ensure high precision and consistency during the cutting process.

It is usually equipped with cutting knives or blades to enable fast and accurate cutting of prepreg or prepreg tape, meeting specific product requirements.

The traverse spooling machine is widely used in the manufacturing of composite materials, flexible pipes, and other industries.

Utilizing a narrow prepreg slitting machine can enhance production efficiency and ensure the stability and reliability of product quality.

It is suitable for both large-scale and customized production needs, offering efficient and precise cutting solutions for the production process.

There are two approaches to consider when using the narrow tape slitting machine.

The first method involves integrating slitting and spooling functions into a single machine.

The slitting machine typically consists of an unwind stand, a web guide system, a slitting station, a guiding station, and a winding station.

Initially, the prepreg or continuous fiber-reinforced unidirectional tape is unwound from the unwind stand and adjusted by the web guiding station to ensure material flatness and accurate positioning.

The material then enters the slitting station, where it is precisely cut into the required narrow prepreg width.

Subsequently, the guide station ensures the correct position and orientation of the slitted prepreg strips.

Finally, the narrow tape enters the winding station for spooling or storage. Simultaneously, the final winding may also involve PE film rewinding.

The second approach focuses solely on slitting the prepreg or UD tape without including the winding function.

In this case, the slitter’s primary objective is to cut the prepreg into narrow strips of the required width.

These narrow tapes are typically used in subsequent process steps, such as further processing, winding, or assembly.

This slitting method delivers high precision and consistent cutting results to meet specific product requirements.

Selecting a narrow tape slitting machine with the appropriate working method, depending on needs and application scenarios, can enhance production efficiency and ensure the quality and specification consistency of the required narrow tape.

In our collaboration with Shandong Non-metallic Materials Research Institute, specifically China Ordnance Industry Corporation (Norinco), we achieved success in the field of thermoplastic unidirectional prepreg tape delivery in 2020.

However, we recognized the pressing demand for slitting thermoset carbon fiber aerospace prepreg.

Consequently, at the end of 2020, we initiated a new project and showcased the first-generation experimental machine at the Guangdong Composites Exhibition in April of the following year.

The China Aerospace Science and Industry Corporation 306 Institute recognized our display, marking a new chapter in our joint research and development efforts.

Before this, we had a certain understanding of thermoplastic materials, but thermosetting carbon fiber was a new realm.

Epoxy resin, phenolic resin, and bismaleimide resin, known for their high viscosity and surface tension, presented significant challenges in material transmission, and cutting tool usage.

Due to our limited experience with these material properties, the initial model’s design was simplistic, lacking optimization in structure, and exhibiting low working precision.

Simultaneously, the doctoral team from the 306 Institute intensified research efforts, constantly fine-tuning the resin process.

Approximately every two weeks, they visited our site in Kunshan for cutting and proofing, meticulously recording data.

The cut materials underwent testing and inspection using the automated fiber placement machine, following which we provided feedback and collaboratively discussed research plans.

Each time the resin formula improved; they brought 5-6 products for machine testing.

We optimized the corresponding mechanical structure and control system based on the materials they provided.

Throughout this process, we persistently explored, resolving each challenge with determination and tenacity.

After 18 months of hard work, we finally glimpsed the dawn of victory.

Our equipment successfully passed rigorous testing, while the resin research and development undertaken by the 306 team reached new heights.

This scientific expedition was a journey starting from scratch, marked by confusion and despair, but we remained resolute, reaching the end.

It was a path fraught with challenges and struggles, but it also witnessed our growth and progress.

The above represents the first part of the discussion on the narrow prepreg slitting machine.

In the subsequent article, we will delve into the details of the slitting machine.