Composite/frp resin penetration molding process
with the development of the industry, there is a higher demand for production speed. Relying solely on the traditional hand paste molding process has been difficult to meet the growing market demand. Therefore, the automation of processing technology is an inevitable trend to comply with this trend
the most common automatic molding process is resin transfer molding process, sometimes referred to as liquid molding process. Resin transfer molding process is a very simple molding process: its principle is to first lay dry preforms of reinforcement materials in a closed mold made of metal or composite materials, then measure and fully mix the resin and catalyst in a certain proportion, and then inject the resin into the mold through the injection port with pressure through the injection equipment, so that the resin can infiltrate the reinforcement materials according to the pre-designed path. Resin transfer molding process requires very low viscosity resin, especially when the preform is thick, better resin fluidity can ensure more timely and sufficient infiltration effect. If necessary, due to the existence of molds and these problems, China's plastic machinery industry can not meet foreign plastic machinery as soon as possible. The horizontal resin can be heated, but the curing of the molding process does not need to use a autoclave. However, some products applied to high temperature are usually post cured after demoulding. Most applications use two-component epoxy formulations: bismaleimide and polyimide resins. The formulation process of components will not be carried out too early, usually before injection
light resin transfer molding process is a low-cost molding process that has developed rapidly in recent years. It is a variant process of resin transfer molding workers. The light resin transfer molding process not only has all the characteristics of the process, but also reduces the requirements of the molding process for a series of indicators, such as injection pressure, vacuum coupling, mold cost and rigidity indicators
resin transfer molding process has many significant advantages. Generally speaking, the intervention molding and resin materials used in the resin transfer molding process are cheaper than prepregs, and can be stored at room temperature. Using this process, thick net formed parts can be produced without many subsequent processing procedures. This process can also help to produce complex parts with accurate dimensions and exquisite surface workmanship. Another feature of the resin transfer molding process is that it allows the core mold filling material to be placed in the preform before the mold is closed, so as to avoid the preform being extruded during the mold closing process. The proportion of core mold in the whole preform is low, about% between. In short, resin transfer molding process can be used as an efficient and repeatable automatic manufacturing process to significantly reduce the processing and molding time, and shorten the traditional hand paste molding time from a few days to a few hours, or even minutes
different from resin transfer molding process (in the order of mixing and injecting the resin and catalyst into the mold in advance, the principle of the reaction injection molding process is to inject the rapid curing resin and catalyst into the mold respectively. The mixing and chemical reaction processes are carried out in the mold, not in the mixing head. Many automobile manufacturers use the preparation method combining the structural reaction injection molding process and the rapid pre molding method to manufacture automobile structural parts, and the products produced do not need to be surface treated High quality processing. Programmable robot has developed into a common spray method, which can spray the mixture of chopped glass fiber and adhesive onto the vacuum preform mold. The biggest feature of robot spraying is that it can control the direction of fibers. In addition, there is a related technology, dry fiber laying technology, which combines the woven preform and resin transfer molding process. The fiber content of the product prepared by this technology is as high as 68%. Because the automatic control process is adopted in the whole process to ensure low bubble content and stable replication and forming effect, the prepared product does not need to be trimmed
vacuum assisted resin transfer molding process is a new molding technology with the fastest development rate in recent years. The main difference between the vacuum assisted resin transfer molding process and the standard resin transfer molding process is that VARTM is a method of using vacuum to inject resin into the mold, while RTM is a way of using pressure to pump the mixture into the mold. Vacuum assisted resin transfer molding process (there is no need for high temperature or high pressure. For this reason, VARTM process can not only use low-cost tools, but also produce complex large parts at one time.
in the VARTM molding process, fiber reinforced materials are placed in a single-sided mold, and the upper surface is covered with a hard or elastic vacuum sealing film. Usually, the resin is designed through magnesium alloy, which is the lightest kind of metal structural materials often used Judging from the export amount of each month in 2013, the electronic experimental machine with a capacity of less than 30t, which uses the vacuum suction injection principle to enter the mold, and then penetrates into the reinforced material in a planned way according to the preset path, has more advantages, greatly simplifying the infiltration treatment of fibers. The fiber content of the product prepared by this process is as high as 70%. At present, the technology is mainly used in the fields of ocean, ground transportation and infrastructure
resin membrane infiltration process is a mixed molding process, which places the intervention molding body in the mold and covers the following layer of high viscosity (high molecular weight) resin film layer, or when the paving layer is thick, the preform and resin are interlaced, and then the high molecular weight resin in the mold is melted by heating the mold and vacuuming, so as to evenly and fully infiltrate the preform. A major feature of the molding process is that the resin penetration process is short, and the resin is evenly distributed, and high molecular weight resin can be used. (end)
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