Encyclopedia of composite material forming process
The composite material forming process is the basis and condition for the development of the composite material industry. With the widening of the application field of composite materials, the composite material industry has developed rapidly, some molding processes have been improved day by day, and new molding methods have been emerging. At present, there are more than 20 molding methods for glass fiber composite materials, and they are successfully used in industrial production ,like:
●Hand lay-up molding process--wet lay-up molding method; ●Injection Molding Process - Fiberglass Spray Up Composite
●Resin transfer molding technology (RTM technology); ●Bag pressing method (pressure bag method) molding; ●Vacuum bag forming; ●Autoclave forming technology; ●Hydraulic still method forming technology; ●Thermal expansion molding technology; ●Sandwich structure forming technology; ●Molding material production process;
●ZMC molding material injection technology; ●Compression molding process; ●Laminate production technology; ●Rolled tube forming technology; ●Forming technology of filament winding products;
●Continuous panel production process; ●Casting molding technology;
Depending on the resin matrix material chosen, the above methods are suitable for the production of thermoset and thermoplastic composites, respectively, and some processes are suitable for both. Compared with other material processing techniques, the composite material forming process has the following characteristics:
(1) In general, in the production process of composite materials, the properties of the materials must be designed according to the use requirements of the products. Therefore, the physical and chemical properties of the products must be satisfied when selecting materials, designing ratios, determining fiber layups and forming methods. , structural shape and appearance quality requirements.
(2) The molding of products is relatively simple. Generally, the resin matrix of thermosetting composite materials is flowing liquid before molding, and the reinforcing material is soft fiber or fabric. Therefore, the production of composite products with these materials requires simpler processes and equipment than other materials. Many, such as waterproof building materials, can be produced with only one set of molds for some products.
Contact low pressure forming process The Contact Low Pressure Molding process is characterized by placing reinforcements by hand, leaching resin, or using simple tools to assist in the placement of reinforcements and resins. Another feature of the contact low pressure molding process is that there is no need to apply molding pressure during the molding process (contact molding), or only a low molding pressure (0.01-0.7MPa pressure is applied after contact molding, and the maximum pressure does not exceed 2.0MPa).
Sandwich Structure Manufacturing Technology Sandwich structures are generally composites made of three layers of material. The upper and lower layers of the sandwich composite material are high-strength and high-modulus materials, and the middle layer is a thicker lightweight material. Hebei Yuniu Fiberglass Manufacturing Co., Ltd. adopts the sandwich structure manufacturing technology, which is actually a composite material and other lightweight materials. recombination. The use of sandwich structure is to improve the effective utilization of materials and reduce the weight of the structure. Taking beam-slab components as an example, in the process of use, it is necessary to meet the requirements of strength and rigidity. The characteristics of FRP materials are high strength, Modulus is low.
Compression molding process There are many varieties of molding materials, which can be prepreg materials, premix materials, or blanks. The main varieties of molding materials currently used are: prepreg, carbon fiber premix, BMC, DMC, HMC, SMC, XMC, TMC and ZMC, etc.
Winding forming process The winding molding process is to wind the continuous fiber (or cloth tape, tex roving) soaked in the resin glue on the core mold according to a certain rule, and then solidify and demould to obtain the product. According to the different physical and chemical states of the resin matrix during filament winding molding, it is divided into three types: dry winding, wet winding and semi-dry winding.
Continuous forming process The continuous molding process of composite products refers to the whole process from the input of raw materials, through the processes of dipping, molding, curing, demolding, cutting, etc., until the final product is obtained. According to the different products produced, the continuous forming process is divided into three types: continuous pultrusion, continuous winding and continuous plate making. The continuous plate making process mainly uses woven fiberglass mat and woven fiberglass cloth as reinforcing materials to continuously produce various specifications of flat plates, corrugated plates and sandwich structure plates.
Thermoplastic Composites Forming Process Thermoplastic composite material is a general term for various thermoplastic resins reinforced by glass fiber, carbon fiber, aramid fiber, etc. It is called FRTP (Fiber Rinforced Thermo Plastics) abroad. Due to the different types of thermoplastic resins and reinforcing materials, the production process and the properties of the composite materials made vary widely.