Molding processes of composite materials serve as the foundation and prerequisite for the development of the composite material industry. With the expansion of application fields for composite materials, the composite material industry has achieved rapid growth. Some molding processes have become increasingly sophisticated, while new molding methods continue to emerge. Currently, there are more than 20 molding methods for polymer matrix composites (PMCs), which have been successfully applied in industrial production, such as:

(1) Hand Lay-up Molding Process – Wet Lay-up Molding Method;(2) Spray-up Molding Process;(3) Resin Transfer Molding (RTM) Technology;(4) Bag Molding Process (Pressure Bag Method);(5) Vacuum Bag Molding Process;(6) Autoclave Molding Technology;(7) Hydraulic Autoclave Molding Technology;(8) Thermal Expansion Molding Technology;(9) Sandwich Structure Molding Technology;(10) Mold Compound Production Process;(11) ZMC Mold Compound Injection Technology;(12) Compression Molding Process;(13) Laminated Plate Production Technology;(14) Wound Pipe Molding Technology;(15) Filament Wound Product Molding Technology;(16) Continuous Plate Production Process;(17) Casting Molding Technology;(18) Pultrusion Molding Process;(19) Continuous Winding Pipe Production Process;(20) Woven Composite Manufacturing Technology;(21) Thermoplastic Sheet Molding Compound (SMC) Manufacturing Technology and Cold Mold Stamping Molding Process;(22) Injection Molding Process;(23) Extrusion Molding Process;(24) Centrifugal Casting Pipe Molding Process;(25) Other Molding Technologies.

Depending on the type of resin matrix material used, the aforementioned methods are respectively suitable for the production of thermosetting and thermoplastic composite materials, and some processes are applicable to both.

Characteristics of Composite Product Molding Processes

Compared with other material processing technologies, composite material molding processes have the following characteristics:

(1) Simultaneous completion of material manufacturing and product moldingIn general, the production process of composite materials is also the molding process of products. The performance of the material must be designed according to the service requirements of the product. Therefore, when selecting materials, designing proportions, determining fiber lay-up, and choosing molding methods, all must meet the requirements for the product’s physical and chemical properties, structural shape, and appearance quality.

(2) Relatively simple product moldingThe resin matrix of general thermosetting composite materials is a flowable liquid before molding, and the reinforcing material is soft fiber or fabric. Therefore, the production of composite products using these materials requires far fewer processes and equipment than other materials; for some products, only one set of molds is needed for production.