The carbon fiber wound composite cylinders have better performance than metal cylinders (steel cylinders, aluminum seamless cylinders) which are made of a single material such as aluminum and steel. It increased gas storage capacity but are 50% lighter than metal cylinders of the same volume, offers good corrosion resistance and not pollute the medium. Carbon fiber composite material layer is composed of carbon fiber and matrix. The carbon fiber impregnated with resin glue solution is wound to the lining in a specific way, and then the carbon fiber composite pressure vessel is obtained after high temperature curing and other processes.
Carbon fiber wound high-pressure gas cylinders are widely used in automobile, aviation, health care, fire protection, mining, gas analysis and special equipment, such as medical breathing apparatus systems, including household and medical oxygen breathing apparatus, self-contained positive pressure air breathing apparatus for fire protection and compressed oxygen circulating breathing apparatus for rescue; Aeration device of escape slide, ejection seat and shell of aircraft in aerospace field; In the field of new energy vehicles, such compressed natural gas cylinders as steel liner carbon fiber annular wound steel composite cylinder (CNG-2), aluminum liner carbon fiber fully wound composite cylinder (CNG-3), plastic liner fully wound composite cylinder (CNG-4), etc. Do you know how was the high-pressure carbon fiber composite gas cylinders made?
T700 carbon fiber, 6061 aluminum alloy metal lining, outer diameter 404mm, total length 668mm, bottle body thickness 1.6mm
CNC winding machine wound 10mm thick composite material on the metal lining surface, oven rotary curing.
High pressure cylinder winding process
In the process of carbon fiber winding, the carbon fiber bundles are continuously wound around the rotating axis to form a cylindrical structure under the action of tension. There are two fiber winding processes of high pressure gas cylinder CFRP: the first is dry winding, which is made of prepreg tape treated with prepreg adhesive and then wound on the mandure after being softened to a viscous flow state by heating on the winding machine, as shown in the figure.
Accurate control of the ratio of fiber and resin content in the prepreg can improve the product quality, high production efficiency, winding speed up to 100 ~ 200m/min. However, this method is less applied due to the high cost of prepredation and dry winding equipment.
Another method is wet winding, in which the carbon fiber bundles are impregnated in a specific adhesive dipping device and then directly wound to the mandrel under tension control, as shown in the figure.
In the wet winding process, the fiber is easy to take out the resin after leaving the macerating device, which can reduce the winding speed and avoid waste. At the same time, the constant loss of resin and carbon fiber ratio is difficult to control, solvent volatile will also produce odor.
In addition to the above obvious disadvantages, wet winding process also has some significant advantages compared with dry winding: first, the production cost is about 40% lower than dry winding; Secondly, the product is well sealed, the tension in the winding process can make the excess resin glue liquid will bubble extrusion and fill the gap; Finally, the resin solution impregnated on the surface of carbon fiber can effectively reduce the fiber wear, which is the most commonly used processing technology for high-pressure gas cylinders.