What is thermoplastic composite material?
In recent years, the development of fiber reinforced thermoplastic composites based on thermoplastic resin is rapid, and the research and development of this kind of high performance composites is starting in the world. Thermoplastic composites refer to thermoplastic polymers (such as polyethylene (PE), polyamide (PA), polyphenylene sulfide (PPS), polyether imide (PEI), polyether ketone (PEKK) and polyether ether ketone (PEEK) as matrix. Composite materials made of various continuous/discontinuous fibers (such as carbon fiber, glass fiber, arylon fiber, etc.) as reinforcement materials.
Thermoplastic lipid-based composites mainly include long fiber reinforced granular (LFT) continuous fiber reinforced prepreg MT and glass fiber reinforced thermoplastic composites (CMT). According to different use requirements, the resin matrix includes PPE-Paprt, PELPCPES, PEEKPI, PA and other thermoplastic engineering plastics, and the dimension includes all possible fiber varieties such as glass dry viscose aryl fiber and boron fiber. With the development of the technology of thermoplastic resin matrix composite and its recyclability, the development of this kind of composite material is faster. The thermal supercompound has accounted for more than 30% of the total amount of tree matrix composite material in developed countries in Europe and America.
Thermoplastic matrix
Thermoplastic matrix is a kind of thermoplastic material, it has good mechanical properties and heat resistance, can be used in the manufacture of various industrial supplies. Thermoplastic matrix is characterized by high strength, high heat resistance and good corrosion resistance.
At present, thermoplastic resins applied to the aviation field are mainly high temperature resistant and high performance resin matrix, including PEEK, PPS and PEI. Among them, amorphous PEI is more widely used in aircraft structure than semi-crystalline PPS and PEEK with high molding temperature because of its lower processing temperature and processing cost.
Thermoplastic resin has better mechanical properties and chemical corrosion resistance, higher service temperature, high specific strength and hardness, excellent fracture toughness and damage tolerance, excellent fatigue resistance, can be molded into complex geometric shape and structure, adjustable thermal conductivity, recyclability, good stability in harsh environment, repeatable molding, welding and repair characteristics.
The composite material composed of thermoplastic resin and reinforcement material has durability, high toughness, high impact resistance and damage tolerance. Fiber prepreg no longer need to be stored at low temperature, unlimited prepreg storage period; Short forming cycle, welding, high production efficiency, easy to repair; The waste can be recycled; The product design freedom is large, can be made into complex shape, forming adaptability and many other advantages.
Reinforcing material
The properties of thermoplastic composites not only depend on the properties of resin and reinforced fiber, but also closely related to the fiber reinforcement mode. The fiber reinforcement mode of thermoplastic composites includes three basic forms: short fiber reinforcement, long fiber reinforcement and continuous fiber reinforcement.
In general, staple reinforced fibers are 0.2 to 0.6mm long, and since most fibers are less than 70μm in diameter, staple fibers look more like powder. Short fiber reinforced thermoplastics are generally manufactured by mixing fibers into a molten thermoplastic. The fiber length and random orientation in the matrix make it relatively easy to achieve good wetting. Compared to long fiber and continuous fiber reinforced materials, short fiber composites are easiest to manufacture with minimal improvement in mechanical properties. Staple fiber composites tend to be molded or extruded to form final components because staple fibers have less effect on fluidity.
The fiber length of long fiber reinforced composites is generally about 20mm, which is usually prepared by continuous fiber wetted into resin and cut into a certain length. The common process used is the pultrusion process, which is produced by drawing a continuous roving mixture of fiber and thermoplastic resin through a special molding die. At present, the structural properties of long fiber reinforced PEEK thermoplastic composite can reach more than 200MPa and the modulus can reach more than 20GPa by FDM printing, and the properties will be better by injection molding.
The fibers in continuous fiber reinforced composites are “continuous” and vary in length from a few meters to several thousand meters. Continuous fiber composites generally provide laminates, prepregs, or braided fabrics, etc., formed by impregnating the continuous fibers with the desired thermoplastic matrix.
What are the characteristics of fiber-reinforced composites
Fiber reinforced composite is made of reinforced fiber materials, such as glass fiber, carbon fiber, aramid fiber, and matrix materials through winding, molding or pultrusion molding process. According to the different reinforcement materials, common fiber reinforced composites can be divided into glass fiber reinforced composite (GFRP), carbon fiber reinforced composite (CFRP) and aramid fiber reinforced composite (AFRP).
Fiber reinforced composites have the following characteristics :
(1) high specific strength and large specific modulus;
(2) The material properties are designable ;
(3) good corrosion resistance and durability;
(4) The coefficient of thermal expansion is similar to that of concrete.
These characteristics make FRP materials can meet the needs of the development of modern structures to large span, towering, heavy load, light and high strength and work under harsh conditions, but also to meet the requirements of the development of modern construction industrialization, so it is more and more widely used in a variety of civil buildings, Bridges, highways, oceans, hydraulic structures and underground structures and other fields.
Thermoplastic composites have great development prospects
According to the report, the global thermoplastic composites market is expected to reach US $66.2 billion by 2030, with a compound annual growth rate of 7.8% during the forecast period. This increase can be attributed to growing product demand in the aerospace and automotive sectors and exponential growth in the construction sector. Thermoplastic composites are used in the construction of residential buildings, infrastructure and water supply facilities. Properties such as excellent strength, toughness, and the ability to be recycled and remolded make thermoplastic composites ideal for building applications.
Thermoplastic composites will also be used to produce storage tanks, lightweight structures, window frames, telephone poles, railings, pipes, panels and doors. The automotive industry is one of the key application areas. Manufacturers are focusing on improving fuel efficiency by replacing metals and steel with lightweight thermoplastic composites. Carbon fiber, for example, weighs one-fifth as much as steel, so it helps reduce the overall weight of the vehicle. According to the European Commission, the carbon emission cap target for cars will be raised from 130 grams per kilometer to 95 grams per kilometer by 2024, which is expected to increase demand for thermoplastic composites in the automotive manufacturing industry.
The prospect of thermoplastic composites is huge, and domestic manufacturers are investing heavily in research and development. We hope that with the joint efforts of everyone in the future, domestic composite technology can be in the international leading position.
Post time: Apr-21-2023