Carbon Fiber Filament Winding Process

Filament winding is the oldest processing method of composite materials, which originated in the late 1950s. As an advanced processing technology at that time, it was first widely used in military industry, such as rocket engine shell and pressure chamber. With the development of science and technology and the wide demand and application of composite materials in society, filament winding methods are more and more applied to the processing of civilian products.

However, in the increasingly fierce competition in the composite processing market, it is not only necessary to have advanced processing equipment, but also have higher and higher requirements for the materials, cost, efficiency and other aspects applied in the processing process. The filament wound process also derives several different processes according to different needs.

So far, filament winding technology is mainly divided into three categories: 1 Wet filament winding process; 2. Dry filament winding process; 3. Semi dry filament winding process.

1. Wet filament winding process

The continuous fiber roving or fabric belt is impregnated with resin, wound directly on the core mold or lining, and then cured this method is called wet filament wound process. Wet filament winding requires relatively simple device, and the requirements for carbon yarn are not strict. 1K, 3k, 6K, 12K or even 24K can be used. However, for the cost, the heavier the yarn, the higher the winding efficiency. Because it is a wet process, all required resins are also liquid, which requires attention to the effective liquefaction time and fluidity of the resin. In the process of processing, we should also pay close attention to the tension of yarn, the content and humidity of resin, and the mess of yarn.

2. Dry filament winding process

After prepreging the continuous carbon fiber roving with resin, heat it at a certain temperature for a certain time to remove the solvent and make the resin from stage A to stage B, the prepreg yarns or prepreg tapes are made. During winding, the prepreg yarns or prepreg tapes are directly wound according to the requirement set in machine on the core mold or liner is called dry filament winding process. As suggested, the carbon yarns we use is a prepreg material, which can be directly wound on the products. This method is very efficient, but the requirements for prepreg yarn are very high. At present, this prepreg yarn has not reached mass production and needs time to wait.

3. Semi dry filament winding process

Compared with the wet filament winding process, the semi filament dry winding process increases the drying procedure; Compared with dry filamenSemi dry filament winding processt winding, the drying time is shortened the drying degree of carbon fiber is reduced and can be wound at room temperature. The fabric is first soaked with resin, then dried, and then wound. This reduces the dependence on equipment and prepreg carbon fabric, improves the quality compared with wet process, and greatly improves the qualified rate of products. It belongs to the processing technology with the highest cost performance at present.

The following table shows the comparison of various filament winding methods, from which we can see the advantages and disadvantages of different process methods.

Name	Working Condition	Resin Content	Yarns	Storage	Quality	Application
Wet filament winding process	Not good	Not easy to control	Any yarns	Common	Bubbles,blemish	Extensive use
Dry filament winding process	Best	Better	Some yarns	Frozen and record	Better	Aviation
Semi-dry filament winding process	Good	Good	Any yarns	Frozen, but short period	Good	Aviation

Although the filament winding process is becoming more and more mature and perfect. Based on the strength of different factories and the different needs of customers, not all composite products need to be applied to the most advanced winding process, but the tension generated by winding can obtain better high-pressure solid, high content of fiber and low blemish products than other composite processing processes, It is more helpful for the products to obtain better mechanical properties. The pursuit of more perfect filament winding process, more efficient and lower cost operation still needs the efforts of all parties.

Edit: YuYang Wang(Intern)