The handling and guiding methods of carbon fibers
to prevent filament damage is often overlooked. However, it is an extremely important factor in carbon fiber production and downstream processes using carbon fiber.

Redirection with sharp angles, use of guides without proper surface finish, excessive tension, static contact points: these are all factors that can induce damage to the filaments in the carbon fiber tow. Broken filaments not only degrade the strength of the carbon fiber, but also cause issues in processing leading to production downtime.

Broken filaments accumulate on rotating parts and will snowball into a mess quickly, which not only needs an operator to intervene but can stop production or create defects in the product.

The main reason proper assessments are not made for fiber damage caused by inadequate handling is that there have been no quantitative means to measure fiber damage. Read more to find out about tools to accomplish this and some analyzation studies.

Winding fibers to produce bobbins or fiber packages is a necessary evil in many composite production processes. Winding is an intermediate step and does not contribute to the production of the final product. If possible, it would be preferred not to wind, and instead take the fibers directly to the final product.

However, composite manufacturing processes come in all shapes, speeds, and sizes, so integrating the composite manufacturing process with the actual fiber production process is impossible. Therefore, we are left with the task of winding the fiber to an easy to handle form to take it to the next process.

When winding carbon fibers in particular, there are three main objectives:

1 – Good build shape of package

2 – No twist in the fiber

3 – Minimal damage of the filaments

The means of achieving these properties vary depending on the type of fiber, number of filaments in the tow, sizing type/content and various other factors. This may require actual test winding, but typically we can assist you based on our decades of experience as well. Optimum winding parameters such as tension or wind ratios are difficult to determine without experience and our team of engineers can help you achieve the winding characteristic desired.

In this article, we would like to go over the different types of winders available and what applications they are the most fit for.

With the increasing variety of resin systems available for carbon fiber and other high-performance fibers, there is a growing need for development of sizing materials which interface well with each resin/fiber combination.

For the development of the sizing material, it is often difficult to experiment without obtaining un-sized fiber. Unless you produce the fiber in your own facility, in many cases it would be necessary to de-size the fiber first, and then apply the desired sizing materials.

The importance of the accuracy of the tension coming off of a creel or let-off is forgotten at times.  Extensive design effort is put into the equipment to actually produce the sheet or tube formed from carbon fiber, but in many cases the front end of this process is overlooked.

The accuracy of tension coming off of the creel can influence the mechanical properties of the part, and either enhance or degrade it depending on the tension control. In some cases, it is not the absolute value of tension which is important, but the minimization of deviation of tension between ends. A single tow of fiber with higher tension than the others could degrade a UD sheet or a pultruded part….etc.

We have many success stories from our customers implementing our creels. Uniformity and improved characteristics of a UD sheet or tape, better mechanical properties observed in a pultruded part, stronger filament wound products, and better strength in a woven fabric.

See the details below for further types of creels available.

After 40 years in the textile and fiber industry, we here at Izumi International often see common errors in the fiber production process.

For one, correct tension control is commonly overlooked in composite material manufacturing.

Even with the most modern equipment, if the starting tension at the creel is not controlled properly, then the final product may be constructed of fibers with varying tension. As a result, it will not fully utilize the strength of all fibers equally. This can degrade the mechanical properties of the final product.

In other cases, we see applications where tension on fibers is so high that it causes filament damage. This can also degrade the quality of the final product.

Whether you specialize in the production of carbon fiber, textile fiber, fabric, film, or any other kind of fiber or web product, proper measurements of length and speed are vital to your success.

Accurate and stable speed and length measurements ensure consistent output for your fiber or web material process. Inaccuracy in a processing line can result in various problems. If you produce less material than your equipment setting indicates, you’ll upset your customer; producing too much means a profit loss for your company.

Many companies rely on the speed or length counters which are initially included on the equipment. But as time passes, how do you know that reading is accurate?