Although the current market share of FRP pipe is not much, in a specific field, FRP pipe can be said to be irreplaceable. Let’s talk about the manufacturing process and points of attention of FRP winding process today.
The winding process is the main way to manufacture FRP pipes. There are seven steps that make up the manufacturing process of the FRP winding process.
Regarding mold manufacturing, you can find it in the previous article. Before the winding process is made, the surface of the mold needs to be treated. This step is done to facilitate the demolding of the product. For different winding products, there are the following two treatment methods:
①Wrap a layer of PET film on the surface of the mold. Cover the PTE film evenly on the surface of the mold, so that there is an isolation layer between the FRP and the mold to prevent difficult demoulding or even pipe burst caused by the adhesion of the FRP and the mold. This treatment method needs to pay attention to the good coverage of the PET film, and no gaps should be left, otherwise it will not play the role of isolation. This method of treatment will have a fatal shortcoming-there will be traces of PET film on the inner wall of the FRP pipe, which leads to the low precision of the inner wall of the FRP pipe.
②For high-precision tubes such as medical tubes, it is necessary to apply a release agent directly on the surface of the mold. The number of coats of release agent shall not be less than 5 to prevent missed coating. The disadvantage of this treatment method is that it requires a high degree of finish of the mold itself. Generally, a finish of 0.8 is required to be smoothly demolded.
The winding process is the main part of the manufacturing process of the glass FRP winding process. According to the different requirements of the customer, the driving program suitable for the product is written. During the winding process, the state of the fiber yarn in the yarn collection car must be paid attention to, and the yarn breakage must be remedied in time. . Note that when winding, the number of hoop winding layers is not more than one layer, and the glass fiber cloth plies should be done at least once during the winding process.
Although the curing process does not have technical requirements in the manufacturing process of the FRP winding process, it is the most problematic process in the winding process, because once the product is not cured, the mold is released, and there will be many problems that follow. More than 90% of problems such as elliptical deformation and poor straightness of FRP pipe are caused by poor curing, and even more will affect the interlayer shear force of FRP pipe. The two curing methods and curing time are as follows:
①Natural curing, the rotation time is not less than 1 hour, and the standing time is not less than 2 hours;
②Heat curing, the rotation time is not less than 1 hour, and the standing time is not less than 1 hour.
4. Cutting and repairing
In terms of repair, different repair plans are made according to the requirements of each customer, and even some customers’ products do not need to be repaired. For products that need to be repaired, attention should be paid to prevent secondary damage to the product during the repair process, so metal products are prohibited on the repair table.
5. Spray paint
Like the repair process, some customers do not need it, but for products that need to be painted, this process becomes the face of the FRP winding process manufacturing process. Pay attention to the thickness of the spray paint, not too thick, easy to run oil; not too thin , easy to show the bottom.
6. Paint surface curing
The curing of the paint surface mainly needs to pay attention to the curing environment and temperature. A bad curing environment may cause dust or different colors on the surface of the product; if the curing time is not enough, the hardness of the paint will not reach.
7. Pack and ship
The product at the time of packaging is already a qualified product, but if damage occurs during the packaging process and is not found, you may soon have to deal with the customer complaint.Therefore, the cleaning of the packaging table is particularly important, and metal tools are strictly prohibited from being placed on the packaging table.