Put the carbon fiber prepreg between the upper and lower molds, close the mold and place the mold on the hydroforming table. After a certain period of high temperature and high pressure to cure the resin, remove the carbon fiber product. This molding technology has the advantages of high efficiency, good quality of parts, high dimensional accuracy, and little impact on the environment. It is suitable for the molding of composite parts with high strength and batch production. However, the mold manufacturing in the early stage is complicated and the investment is high, and the size of the workpiece is limited by the size of the press.
The compression molding process has the following 7 steps:
1. Insert placement
The insert is generally made of metal, which can strengthen the product, and the mechanical properties of the product using the insert are greatly improved. There are also inlays added in order to impart electrical and thermal conductivity or other functional properties to the product. Before placing the insert, it is better to preheat it.
Inserts are usually placed by hand, and the placement should be accurate and stable. For small inserts, pliers or tweezers can also be used to install them. One insert can be used for one product, or several different inserts can be placed. The position must not be misplaced or skewed. The insert must be stable and fixed if necessary to prevent displacement or removal, otherwise it will not be achieved. If the purpose of using the insert is not achieved, it will cause the scrap of the product and even damage the mold.
2. Feeding
The accuracy of the feeding amount will directly affect the size and density of the product, it should be strictly quantified, and the material should be evenly added to the mold groove.
3. Mold closing
Clamping is divided into two steps. Before the punch touches the material, it needs to be fast at low pressure (1.5-3.0MPa). In this way, the cycle can be shortened and plastic changes can be avoided. After the punch touches the material, it should start to close slowly. Mold speed, change to high pressure (15-30MPa) and slow speed, so as not to damage the insert and discharge the air in the mold.
4. Exhaust
In order to remove the air, moisture and volatiles in the mold, after the mold is closed, some need to open the mold for a period of time, this process is called exhaust.
5. Curing
The process of changing the material from a fluid state to a hard, infusible and insoluble state is called the curing of a thermosetting resin. 6. Holding time
The process of resin curing in the mold is always under high temperature and high pressure. The time required from the beginning of temperature rise, pressurization, curing to cooling and pressure reduction is called the holding time.
6. Demolding
The finished product should first use a special tool to unscrew the forming rod, etc., and then demould.
7. Clean the mold
