Brief Introduction to RTM Molding Process of Resin-based Composite Materials

 

The main molding methods of resin-based composite materials are: hand lay-up molding process, injection molding process, resin transfer molding technology, autoclave molding technology, thermal expansion molding technology, sandwich structure molding technology, compression molding process, fiber winding product molding technology, stretch molding process, braided composite material manufacturing technology, injection molding process, etc.

 

Resin transfer molding technology (RTM) has the advantages of high efficiency, low cost, good product quality, high dimensional accuracy, and little environmental impact. It is used for the molding of large-volume, complex-structured, and high-strength composite parts. This process has become one of the most active research directions in the field of aerospace material processing in recent years.

 

Principle

 

The RTM molding process refers to a molding technology in which a fiber-reinforced material preform calculated according to the design requirements is placed in a pre-made mold cavity that meets specific process dimensions, and a special resin system is injected into the closed mold cavity using an injection device within a certain pressure range. Through the infiltration of the resin and the reinforcement, it is solidified and molded into the required high-performance composite material.

 

Figure 1 RTM Molding Process Flow Chart

 

Advantages of RTM Molding Process

 

1. It can manufacture high-quality, high-precision, low-porosity, high-fiber content complex composite structural parts, and can obtain smooth double surfaces without gel coat resin. The product has a short time from design to production and high production efficiency

 

2. The molds and products of the RTM molding process can be designed using CAD, the molds are easy to manufacture, and the material selection is wide. Compared with compression molding, the RTM molding process has low equipment cost, and large products can be produced using small-tonnage presses.

 

3. RTM molded components and management are easy to achieve local enhancement, and locally thickened components and composite materials with core materials can be molded in one go

 

4. The RTM molding process is a closed mold operation, with less pollution and less volatilization during operation, which is beneficial to labor protection and environmental protection

 

 

Figure 2 Fan made of carbon fiber 3D braided composite material RTM