A-14 Automotive Exterior Parts Special Pre impregnated Material

Special yellow and weather resistant carbon fiber prepreg for automotive exterior parts: a dual benchmark for reshaping automotive appearance and performance

In the field of automobile modification and high-end vehicle manufacturing, exterior parts are not only the core carrier of vehicle aesthetic expression, but also need to resist the erosion of complex outdoor environments for a long time. The special prepreg for automotive exterior parts is composed of "special yellow resistant and weather resistant epoxy resin+high-performance carbon fiber" as the core combination, covering two forms of unidirectional carbon fiber prepreg and carbon fiber fabric prepreg. After curing, it has excellent mechanical properties and super strong moisture and heat stability, and can achieve long-term outdoor use without yellowing or performance degradation. Provide material solutions that combine aesthetics and durability for exterior components such as car bumpers, tailwings, engine covers, rearview mirror housings, and car modification parts, breaking the application bottleneck of traditional carbon fiber prepreg that is prone to yellowing and has poor weather resistance.

Core advantages: Multi dimensional breakthroughs in weather resistance, yellowing resistance, stable performance, and aesthetic compatibility

1. Dedicated yellow and weather resistant resin, overcoming the problem of outdoor appearance attenuation

The core technological highlight of this prepreg lies in the dedicated yellow and weather resistant epoxy resin system, which is different from the defects of ordinary epoxy resins that are easily affected by ultraviolet radiation, high temperature, and humidity and undergo yellowing and aging. It achieves a breakthrough in weather resistance through triple technological innovation: firstly, adding efficient ultraviolet absorbers and hindered amine light stabilizers, which can intercept more than 99% of harmful ultraviolet radiation, avoiding resin molecular chains from breaking or oxidizing due to ultraviolet irradiation; The second is to use a low volatility monomer formula to reduce the appearance loss and yellowing caused by the migration of resin small molecules in high-temperature environments; The third is to introduce hydrolysis resistant groups to enhance the stability of the resin in humid environments and prevent performance degradation caused by water molecule penetration.

After authoritative testing, the pre impregnated material specifically designed for automotive exterior components has shown excellent performance in extreme environmental testing: after being placed in a humid and hot aging chamber at 80 ℃ and 95% relative humidity for 1000 hours, there was no significant yellowing of the appearance (yellowing index Δ E<1.5, far below the industry's qualified standard of Δ E<3); In the UV aging test (simulating outdoor exposure), continuous irradiation for 2000 hours resulted in a surface gloss retention rate of over 90% without cracking or delamination. Compared with ordinary carbon fiber prepreg, its yellow and weather resistance has been improved by over 200%, completely solving the pain point of "yellowing and declining appearance" of automotive exterior parts after prolonged use, especially suitable for parts such as tail fins and surrounds that need to be exposed for a long time, ensuring that the vehicle appearance always remains brand new. At the same time, the product density is strictly controlled at no less than 5% to ensure even distribution of carbon fiber and resin, avoiding weak weather resistance points caused by insufficient local density.

2. Dual form product coverage, adapted to the structural and aesthetic needs of different appearance parts

The product family includes unidirectional carbon fiber prepreg and carbon fiber fabric prepreg, which can be flexibly selected according to the structural characteristics, stress requirements, and texture design of automotive exterior parts, achieving precise matching of "function and aesthetics".

• Unidirectional carbon fiber prepreg: It adopts high straightness carbon fiber unidirectional arrangement, with fiber direction consistency of over 99.5%, and outstanding axial mechanical properties. Suitable for large exterior components with high requirements for rigidity and flatness, such as car engine hood and roof trim. The components made of it not only have a weight reduction of more than 40% compared to traditional metal materials, but also present a delicate "straight line texture" through the regular arrangement of unidirectional fibers, which is highly technological when combined with transparent coatings; At the same time, excellent anti bending performance can avoid vibration deformation of the engine hood during high-speed driving, ensuring the integrity of the appearance.
• Carbon fiber fabric prepreg: Based on plain and twill fabrics, it has excellent in-plane isotropy and unique texture. Suitable for exterior parts and car modification parts with complex shapes and emphasis on aesthetic expression, such as rearview mirror housings, rear wings, and side skirts. The plain weave fabric prepreg presents a classic "grid texture", visually exquisite and symmetrical; The pre impregnated twill fabric exhibits a smooth "diagonal texture" with stronger layering, which can meet the personalized appearance needs of modification players. In addition, the impact resistance of the fabric structure is superior, which can effectively resist the appearance damage caused by minor collisions and reduce maintenance costs.

Two forms of prepreg can be used in combination, for example, the car tail can adopt a design of "unidirectional prepreg (main structure, maintaining rigidity)+fabric prepreg (surface layer, showing texture)", which balances structural stability and aesthetic appearance, maximizing product added value.

3. Excellent mechanical performance and wet heat stability ensure long-term reliability of appearance components

As a specialized material for automotive exterior components, this prepreg does not sacrifice the core mechanical properties of carbon fiber in addition to its resistance to yellow and weather. By optimizing the infiltration process of resin and fibers, the resin can fully penetrate into each carbon fiber bundle, increasing the interfacial bonding strength by 25%. The mechanical properties of the cured composite material are outstanding: the 0 ° tensile strength of unidirectional carbon fiber prepreg can reach over 1800MPa, and the bending strength exceeds 1500MPa; The shear strength of carbon fiber fabric prepreg reaches 80MPa, which is sufficient to cope with conventional loads such as wind pressure and vibration during car driving.

At the same time, the product has excellent wet and hot stability, and its performance degradation rate is extremely low in the common alternating environment of "high temperature exposure+rainy and humid" in automobiles. After testing, the mirror housing made of the prepreg was placed in high and low temperature cycles of -40 ℃~120 ℃ for 500 times, and the mechanical performance retention rate still reached over 88% without cracking or deformation; Soak in simulated acid rain environment for 300 hours, with no corrosion marks on the surface and no peeling of resin and fibers, ensuring that the appearance of the parts maintains its appearance and reliable structural performance throughout its entire life cycle (usually 8-10 years), avoiding appearance damage and functional failure caused by material failure.

4. Strong process adaptability to meet the large-scale and customized production of automotive exterior parts

In response to the dual needs of "mass production+personalized modification" of automotive exterior parts, this prepreg has strong process adaptability and can be compatible with mainstream processes such as hot press can molding, compression molding, and vacuum bag molding, without the need for additional equipment modification by enterprises, reducing production barriers.

• Compression molding: suitable for mass production of standardized exterior parts (such as tail fins and surrounds of mass-produced car models), with high molding efficiency. Single mode production time can be controlled within 30-45 minutes, and component size accuracy can be accurately controlled (error ± 0.3mm), ensuring the assembly fit of appearance parts and reducing subsequent polishing and adjustment processes.
• Hot press molding: Suitable for high-end customized exterior parts (such as luxury car engine covers, limited edition modified parts), controlled by uniform pressure (0.8~1.2MPa) and temperature (120~140 ℃), the resin flow of the prepreg is more uniform, and the surface smoothness of the molded parts is high, with clear texture, presenting the original beauty of carbon fiber without additional spraying, reducing production process costs.
• Vacuum bag molding: suitable for large and complex shaped exterior parts (such as integral car surrounds), resin exhaust and infiltration are achieved through vacuum negative pressure, reducing molding costs by 30% compared to hot press can technology, while ensuring the full performance of yellow and weather resistant resin, balancing economy and product quality.

In addition, the product has excellent storage and processing convenience, and can be stored for more than 6 months in a low temperature environment of -18 ℃. After being taken out and warmed up for 30 minutes, it can be put into production, adapting to the flexible production rhythm of the automotive manufacturing and modification industry.

5. Differentiated design, building competitive barriers for automotive exterior materials

On the one hand, differentiated innovation is carried out in resin formula, fiber selection, and texture design - for example, the independently developed "high gloss yellow resistant resin" can make the surface glossiness of the molded appearance parts reach 120GU or more (about 80GU for ordinary products), visually more high-end; On the other hand, we provide flexible customized services that can adjust the fiber surface density (100~600g/㎡ full coverage), resin color (transparent, matte black, etc.), and texture type (plain weave, diagonal weave, satin weave) according to customer needs, to meet the needs of different vehicle exterior designs and modification styles. For example, for the tail wing requirements of sports cars, carbon fiber fabric prepreg with "high rigidity+diagonal texture" can be customized; In response to the demand for rearview mirror housings for retro modified cars, customized models with "matte texture+plain weave texture" can be provided to avoid market pressure caused by homogeneous competition and provide customers with unique product selling points.