Dongguan Keqi Plastic ABS KQ ABS CF30A is a carbon fiber reinforced acrylonitrile-butadiene-styrene compound supplied for injection molding and extrusion. The suffix CF30A is understood to denote a nominal 30% carbon fiber mass fraction, but actual reinforcement level should be verified against the batch certificate because recompounded lots can shift by ±2%. The matrix remains an amorphous styrenic terpolymer, while the carbon fiber contributes stiffness, dimensional stability, and electrical dissipative behavior. Published data for this specific configuration is limited; the processing and property bands referenced in this document are derived from commercial 30% carbon fiber ABS materials and are not a substitute for lot-specific certificate values.

In comparison with unfilled ABS, the compound moves from an unreinforced tensile modulus class of approximately 2,200 to 2,600 MPa into a high-modulus structural thermoplastic class. The grade is black and is not typically color-matched in light shades without surface coating. Because carbon fiber is electrically conductive, pellet handling and regrind operations require static-safe equipment and dust control. Intended applications include load-bearing housings, brackets, industrial jigs, and static-dissipative enclosures where unfilled ABS lacks sufficient modulus and creep resistance.

Before melt processing, the material is dried to a residual moisture content below 0.02%. A desiccant dryer with a dew point of -40°C is recommended. Drying at 80°C to 90°C for 3 to 4 hours is the normal window. At ambient relative humidity above 60%, hopper residence time should not exceed 30 minutes without dry-air blanketing. Regrind usage above 20% is not advised without process validation because repeated thermal history reduces fiber length and impact resistance.

What Melt Processing Conditions Are Required for KQ ABS CF30A?

Injection molding trials on 30% carbon fiber ABS grades indicate that barrel temperatures between 220°C and 260°C preserve fiber length while maintaining melt homogeneity. A reverse-profile barrel setting from approximately 210°C at the rear zone to 250°C at the metering zone is common. The nozzle is normally held between 240°C and 260°C. Mold temperature is maintained between 60°C and 90°C to balance weld-line strength against surface appearance and dimensional repeatability. Back pressure below 1.5 MPa avoids excessive fiber fracture, while screw retraction speed is limited to approximately 100 mm/s to prevent air entrapment.

The molding machine should be configured with a wear-protected barrel, a hardened check ring, and a shut-off nozzle. A low-shear general-purpose screw with an L/D ratio of 20:1 to 24:1 and a compression ratio of 2.0:1 to 2.5:1 is acceptable for most applications. Injection pressure is typically 80 to 140 MPa depending on flow length and wall thickness. For a 2 mm wall, holding pressure of 60 to 100 MPa and pack time of 5 to 10 seconds reduce sink and improve gate sealing. Melt residence time should be kept below 10 minutes to limit degradation of the butadiene phase.

For extrusion compounding or profile extrusion, a single-screw extruder with L/D ratio of 25:1 to 30:1 and a barrier screw is preferred. Die melt temperature should not exceed 240°C. Screen pack filtration of 100 to 150 mesh may be used to remove carbon fiber agglomerates; finer screens increase head pressure and reduce fiber length. Melt viscosity of 30% carbon fiber ABS is higher than unfilled ABS and is shear-thinning. At a shear rate of 1,000 s⁻¹, apparent viscosity for a 30% carbon fiber ABS typically falls between 150 Pa·s and 250 Pa·s. Capillary rheometry according to ISO 11443 is recommended for mold-filling simulation input rather than relying solely on melt volume-flow rate.

Property Benchmarks, Test Standards, and Batch Certificate Boundaries

For process capability assessment, the following matrix lists representative bands for a 30% carbon fiber ABS grade under standard laboratory conditioning at 23°C and 50% relative humidity unless otherwise stated. Values are not producer-guaranteed specifications; they serve as baseline comparators for incoming material evaluation and initial mold design.

The spread between 80 MPa and 110 MPa tensile strength is largely controlled by fiber length retention in the molded part. Sharp runner transitions can shear the fiber population and drive tensile strength toward the lower bound, while a well-designed gate land can preserve longer fibers and move modulus toward the upper bound. The notched Charpy band of 5 to 8 kJ/m² indicates comparatively low ductility; designers should avoid sharp internal corners and direct weld lines in tensile load paths. For regulation-sensitive applications, compliance with RoHS Directive 2011/65/EU, REACH SVHC declarations, and any food-contact requirements must be verified against the supplier’s product declaration because carbon fiber sizing systems are proprietary and may vary by production campaign.

Because carbon fiber differs from glass fiber in modulus, density, and conductivity, KQ ABS CF30A should not be treated as a direct substitute for glass-filled ABS without re-evaluating impact behavior, melt flow, and tool shrinkage. The following comparative matrix summarizes the practical performance boundaries against common reinforced and unreinforced alternatives.

Compared with 30% glass-fiber ABS, the carbon-fiber variant provides lower density, higher tensile modulus, and static-dissipative behavior. The penalty is reduced impact strength, higher melt viscosity, and greater sensitivity to gate location and fiber orientation. Neat ABS is preferred where toughness and surface gloss dominate; KQ ABS CF30A is selected only when the application requires modulus and dimensional stability beyond unreinforced ABS. Compared with carbon-fiber PA66, KQ ABS CF30A melts at a lower temperature and does not require post-molding moisture conditioning to reach stable dimensions, but its maximum service temperature and solvent resistance are lower. The selection boundary between CF30A and CF30 PA66 is normally set by continuous temperature above 100°C or exposure to hydrocarbons and glycols.

If Dimensional Stability and Shrinkage Anisotropy Are Critical

Mold shrinkage in the flow direction typically falls between 0.2% and 0.4%, while transverse shrinkage can reach 0.6% to 1.0%. The differential increases as wall thickness falls below 2 mm because higher shear aligns fibers near the frozen layer. Flat parts with ribs or bosses exhibit bowing if the gate is placed at one end. Mold-filling simulation with an orientation tensor model is recommended before cutting steel for components with thickness transitions greater than 2:1 or with projected areas above 150 cm².

Packing pressure between 60 MPa and 100 MPa and pack time of 5 to 10 seconds for 2 mm walls reduce shrinkage anisotropy but cannot eliminate it. Gate freeze must occur before packing is released. A tab gate of 1.0 mm to 1.5 mm thickness is preferred over pin gates below 0.8 mm because small gates create a high-shear zone and excessive fiber alignment, leading to notch sensitivity at the gate. Post-mold annealing at 80°C for 2 hours may relieve residual stress and improve dimensional stability after machining, but published data for KQ ABS CF30A under this protocol is limited. Parts that require CNC machining should be rough-machined, annealed, and finish-machined to prevent delayed warpage.

Electrostatic dissipative performance in carbon-fiber reinforced ABS is produced by conductive filler percolation, not by migratory antistatic additives. Surface resistivity below 10⁶ Ω/sq at 10 V test voltage is possible, but the value is strongly influenced by molding skin. A resin-rich skin formed against a high-gloss mold surface can raise surface resistivity by one to two decades. For critical static control, volume resistivity per IEC 62631-3-1 is more repeatable than surface resistivity per ASTM D257 because it is less affected by surface contamination and resin skin thickness.

When the part must contact sensitive electronic components, carbon fiber filled ABS can produce localized micro-arcing at sharp fiber ends if voltage is high. Overmolding or surface coating may be required for voltages above 100 V. The material is not generally recommended as a primary RF shielding compound; shielding effectiveness is dependent on thickness, frequency, and fiber network continuity, and published data for this specific configuration is limited. For dry machining of molded parts, conductive carbon fiber dust must be controlled with local exhaust ventilation and HEPA filtration to prevent short circuits in electrical panels and respiratory irritation.

Thermomechanical Performance Remains Matrix-Limited

KQ ABS CF30A retains its fiber stiffness contribution above the matrix glass transition, but the continuous-use ceiling is set by matrix softening rather than fiber degradation. Under mechanical load, service temperature should remain below 90°C; short-term excursions to 110°C are acceptable only when stress is below 10 MPa and part distortion is tolerated. Continuous exposure to 120°C in air will cause progressive surface oxidation and gloss loss. Chemical resistance of the ABS matrix is similar to unfilled ABS. Prolonged contact with ketones, esters, aromatic hydrocarbons, or chlorinated solvents is not recommended. Stress cracking develops more rapidly at gate bosses and weld lines because fiber-filled parts contain higher residual stress. Compatibility with lithium grease, motor oil, and dilute aqueous acid is generally acceptable at room temperature, but part-specific testing under ASTM D543 is required for production release.

Creep testing according to ISO 899-1 at 23°C is recommended for structural applications above 25 MPa sustained load. Carbon fiber lowers creep rate compared with unfilled ABS, but fiber orientation and weld-line placement dominate long-term deformation. If the part contains a weld line in a load-bearing region, a notched Charpy measurement under ISO 179-1/1eA should be combined with a tensile weld-line specimen rather than relying on bulk tensile data alone.

In production trials with 30% carbon fiber ABS compounds, surface splay, jetting, weld-line cracking, and density variation are the most frequently recorded defects. Splay is most commonly caused by residual moisture above 0.02% or by barrel temperatures above 260°C at the nozzle. Jetting occurs when the gate is too small or the injection speed is too high; increasing gate land and reducing initial injection speed to 20 to 40 mm/s prevents free-jet flow. Weld-line strength improves with mold temperature at 90°C and venting at the knit line. Density below 1.18 g/cm³ often indicates short shots, fiber segregation, or excessive regrind; verification should include full shot weight and ash content per ISO 3451-1.

When parts are used in moveable assemblies, thread-forming screws can generate microcracks in bosses if the pilot hole is below 1.5 times the screw minor diameter. Boss design should include a generous radius at the base and a wall thickness of 0.7 to 1.0 times the nominal wall. Ultrasonic welding of KQ ABS CF30A is possible only if the joint is designed with a shear joint rather than an energy director; carbon fiber at the weld interface can act as a stress concentrator and reduce joint efficiency.