Composite Material: A new type of material formed by combining two or more different substances. Generally composed of a matrix component and a reinforcement or functional component.

Carbon Fiber: In simple terms, it is a fibrous carbon material characterized by high strength, high modulus, low density, and corrosion resistance.

Graphite Fiber: Carbon fiber with a graphite molecular structure, containing more than 99% carbon and featuring a layered hexagonal crystal lattice. Carbon fiber subjected to high-temperature heat treatment increases its internal graphitization level. Generally, carbon fiber treated at temperatures above 1800℃ is termed graphite fiber.

Epoxy Resin: A general term for polymers containing two or more epoxy groups in their molecules. It is a condensation product of epichlorohydrin and bisphenol A or polyols. Due to the chemical reactivity of the epoxy groups, it can be cross-linked and cured with various compounds containing active hydrogen to form a thermosetting resin with a network structure. Bisphenol A type epoxy resin is not only the most produced and diverse but also continues to improve in quality with new modified varieties.

Thermosetting: Refers to materials that do not soften and reshape upon reheating and do not dissolve in solvents. Polymers with this property are thermosetting.

Thermoplastic: Refers to materials that can deform and flow when heated and retain a certain shape upon cooling. Most linear polymers exhibit thermoplasticity, making them easy to process through extrusion, injection, or blow molding.

Tensile Strength: The maximum stress a material can withstand when stretched before breaking, indicating the material's resistance to failure.

Tensile Modulus: The elasticity of a material during tension. It is the ratio of the force required to stretch the material by a unit length along the central axis to its cross-sectional area, indicating the material's resistance to deformation.

Poisson's Ratio: The ratio of transverse strain to axial strain in a material under uniaxial tension or compression, also known as the lateral deformation coefficient.

Sizing Agent: A polymer layer applied to carbon fiber strands before collection to protect the carbon fiber and enhance the bonding strength with the matrix.

Elongation at Break: The ratio of the length difference before and after stretching to the initial length when a fiber is pulled until it breaks, expressed as a percentage.

Specific Strength: The strength of a material (force per unit area at break) divided by its density, also known as strength-to-weight ratio.

Specific Modulus: The elastic modulus per unit density, a material property also known as stiffness-to-weight ratio or specific stiffness.

Toughness: Indicates a material's ability to absorb energy during plastic deformation and fracture. Higher toughness reduces the likelihood of brittle fracture.

Isotropy: A property where a material's physical and chemical characteristics do not change with direction, meaning the measured performance values are the same in all directions.

Anisotropy: A property where a material's physical and chemical characteristics vary with direction, showing different properties in different directions.

Prepreg: An intermediate material made by impregnating continuous fibers or fabrics with a resin matrix under controlled conditions, forming a composite of the resin matrix and reinforcement.

Unidirectional Fabric: Also known as UD fabric, it contains a large number of carbon fiber yarns in one direction (usually the warp) and only a few, usually fine, yarns in the other direction, making the fabric's strength primarily in the first direction.

3K Fabric: A fabric woven from 3K carbon fiber tows, available in plain, satin, and twill weaves, commonly used on the surface of carbon fiber products.

Pre-oxidation: The pre-oxidation process that carbon fiber precursors must undergo before carbonization, also called stabilization, to ensure the fibers do not melt or burn during carbonization.

Carbonization: The process of heating carbon fiber precursors or pre-oxidized fibers in the absence of air, causing them to decompose and ultimately form carbon fiber.

Graphitization: The process of subjecting carbon fiber to high-temperature heat treatment to transform its internal carbon atom arrangement from a disordered graphite structure to an ordered graphite crystal structure.

PAN-based: Carbon fiber made by carbonizing polyacrylonitrile fiber precursors is termed PAN-based carbon fiber.

Pitch-based: Carbon fiber made by carbonizing pitch fiber precursors is termed pitch-based carbon fiber.

Viscose-based: Carbon fiber made by carbonizing viscose fiber precursors is termed viscose-based carbon fiber.

Precursor Fiber: An organic fiber formed through spinning, used for producing carbon fiber.

Spinning: Also known as chemical fiber forming, it is a process in chemical fiber manufacturing where high molecular compounds are made into colloidal solutions or molten into melts and then extruded through spinneret holes to form chemical fibers.

Full Mark: Japanese-imported carbon fiber without cut labels is referred to as full mark.

Half Mark: Due to Japan's restrictions on the circulation of carbon fiber exported to China, traceable codes are set in product labels. In China, the traceable codes are cut off to prevent tracking, resulting in half-mark carbon fiber.

Small Tow: Generally considered as carbon fiber with less than 24K filaments, including 1K, 3K, 6K, 12K, and 24K.

Large Tow: Generally considered as carbon fiber with more than 24K filaments.

Wet Spinning: One of the main methods of chemical fiber spinning, abbreviated as wet spinning.

Dry-Jet Wet Spinning: A solution spinning method that combines the characteristics of dry and wet spinning, featuring high stretching ratios at the spinneret and improved fiber bundle expansion in the wet coagulation bath, resulting in a denser structure, higher spinning speeds, and certain initial fiber strength after post-processing to obtain high-performance fibers.

Coefficient of Thermal Expansion: The change in length of a material per unit temperature change under constant pressure, represented by the coefficient of thermal expansion.

Disordered Graphite Structure: A structure where carbon hexagonal rings begin to enlarge and align in parallel at equal distances, but carbon atoms in each plane do not yet exhibit the orderly stacking sequence of graphite crystals, not achieving a three-dimensional ordered state.

Degree of Graphitization: A parameter representing the extent to which the carbon atom structure approaches the perfect graphite crystal structure after high-temperature heat treatment.

Plain Weave: Fabric woven using a plain weave structure, where warp and weft yarns intersect every other yarn, characterized by many interlacing points, firm texture, flat surface, lightweight, good abrasion resistance, and good breathability.

Satin Weave: A general term for fabrics woven using various satin weave structures, where individual interlacing points on adjacent warp or weft yarns are evenly distributed but not contiguous.

Twill Weave: A fabric with a clear diagonal weave pattern, characterized by a two-up, one-down twill weave, and a 45° left diagonal.

Unit Area Density: The weight per square meter for carbon fiber fabric or carbon fiber prepreg.

Warp Yarn: A series of yarns extending in the length direction of the loom, forming the fabric along the length direction.

Weft Yarn: Yarn used in the weft direction during weaving, with warp yarns used in the warp direction.

Core Material: Foam or honeycomb material added between carbon fiber layers in laminated composite panels to enhance the panel's resistance to bending moments.

Three-Dimensional Weaving: Also known as 3D weaving, it involves using methods such as needle collecting and releasing, horizontal holding, wedge weaving, or multi-layer weaving on a weft knitting machine to produce shaped or flat fabrics with three-dimensional structures.

Multiaxial Fabric: A multilayer composite fabric formed by binding warp, weft, and diagonal full-width weft yarn bundles together.

Chopped Carbon Fiber: Carbon fiber cut into short lengths used for reinforcing plastics.

Hot-Melt Prepreg: A method of melting pre-impregnated resin by heating it and impregnating the fibers, used in prepreg production processes.

Solution Prepreg: A method of dissolving pre-impregnated resin in an organic solvent and then impregnating the carbon fiber, used in prepreg production processes.

Coupling Agent: A plastic additive that improves the interfacial properties between synthetic resin and carbon fiber.

Fiber Content: The amount of carbon fiber per unit area.

Resin Content: The amount of resin per unit area.

Bonding: The method of joining two carbon fiber composite components using adhesives.

Mechanical Connection: The method of joining carbon fiber composite components using bolts or riveting.

Z-Pin Connection: A technique where unidirectional composite materials are pultruded into fine rods (commonly known as Z-pins) and embedded into uncured prepreg or fiber preforms. After curing, the Z-pins form "anchoring" Z-direction reinforcement.