PP CF Plastic Pellet Raw Materials

PP CF composite materials mainly consist of two major components:

PP (Polypropylene) Matrix
It makes up a significant portion of the composite, offering basic structure and performance foundation. PP has good chemical stability, electrical insulation, and is easy to process.

Carbon Fibers
Carbon fibers are added to PP as reinforcements. Their content varies from 10% to 50% depending on specific requirements. The diameter is usually between several micrometers and dozens of micrometers. Their surfaces are smooth, and special treatments like surface modification are often needed when combining with the PP matrix.

Taking PP CF30 as an example, it may contain around 30% carbon fibers and about 70% PP matrix. This proportion aims to ensure good mechanical properties and other performances while considering processing and cost.

I. Performance Characteristics

(1) Mechanical Properties
– High Strength: Carbon fibers possess high strength, far exceeding that of PP. Adding them to PP notably improves the tensile, flexural, and impact strengths of PP CF composite materials. For example, short carbon fiber-reinforced PP composites can have 50% – 100% higher tensile strength than pure PP. Long carbon fibers’ reinforcement is even better.
– High Modulus: The high modulus of carbon fibers enhances the rigidity and dimensional stability of PP CF composite materials, making them less likely to deform under external forces, suitable for applications demanding high dimensional accuracy.

(2) Thermal Properties
– Improved Heat Resistance: PP has relatively poor heat resistance, while carbon fibers have high thermal stability. Adding carbon fibers raises the heat distortion temperature and melting point of PP CF composite materials, enabling their use in higher temperature environments.
– Increased Thermal Conductivity: Carbon fibers have high thermal conductivity. Thus, PP CF composite materials have better heat dissipation and conduction than pure PP, applicable in fields such as electronic device heat sinks.

(3) Electrical Properties
– Enhanced Electrical Conductivity: Carbon fibers are conductive. When their content reaches a certain level, PP CF pellets can conduct electricity, facilitating applications in anti-static and electromagnetic shielding fields.

(4) Other Properties
– Good Corrosion Resistance: The excellent corrosion resistance of carbon fibers improves the chemical corrosion resistance of PP CF raw materials, making them usable in harsh chemical environments.
– Damping and Shock Absorption Performance: Carbon fibers have good damping and shock absorption performance. Virgin PP CF granules can absorb energy during vibrations and impacts, reducing vibrations and noises.

II. Distinction between Long and Short Carbon Fibers

(1) Fiber Length and Distribution
– Short Carbon Fibers: Usually less than 1 millimeter, evenly dispersed in the matrix material. This makes the composite materials’ performance relatively balanced in all directions. Due to the short length, the reinforcement effect is relatively weak. However, they are easier to mix with the PP matrix during processing, suitable for applications with high processing requirements.
– Long Carbon Fibers: Their length ranges from 1 to 25 millimeters. They can form a continuous fiber network in the composite materials, providing more consistent load distribution. The reinforcement effect of long fibers is much better than that of short fibers, especially in tensile and impact strengths, which can increase the composite materials’ strength several times or even dozens of times. But long carbon fibers are harder to process and need special equipment and processes.

(2) Reinforcement Effect
– Short Carbon Fibers: Can improve the mechanical properties of PP, like increasing tensile and flexural strengths and moduli, though the improvement is relatively limited. But for pure PP substrates without added carbon fibers, adding short carbon fibers can still significantly improve the strength.
– Long Carbon Fibers: Have a significant effect on improving the mechanical strength of products and are favored in high-performance applications. When the content of continuous carbon fibers reaches a certain percentage, their strength can even exceed that of metal materials like aluminum alloys.

If you’d like to learn more on carbon fiber filled pp plastic granules (PP-CF-BCA3) or other CFRTPs, please click here or directly contact Carbon New Material.