ABS material is widely used in consumer electronics casings, home appliance panels, etc., due to its combination of rigidity, toughness, and processability. However, the Shore hardness of pure ABS products is typically 80-90D, which makes them prone to scratches and wear in daily use, reducing product appearance integrity and service life. Thus, enhancing surface hardness is a core optimization focus in the mass production of ABS products.
Optimizing the base material is a foundational method to improve the surface hardness of ABS products.
Glass Fiber Reinforcement Modification
Adding 10%-30% glass fiber to the ABS matrix can increase the surface hardness by 15%-20% while enhancing rigidity. During production, a twin-screw extruder is required to ensure uniform fiber dispersion, avoiding appearance defects caused by local agglomeration.
Mineral Filler Modification
Adding about 20% mineral fillers (e.g., calcium carbonate, talc) can moderately improve surface hardness at a lower cost than glass fiber modification. However, the filler content must be controlled to prevent excessive reduction in product toughness.
Alloy Modification
Blending ABS with materials like PC or PMMA (e.g., PC/ABS alloy, PMMA/ABS alloy) yields higher surface hardness than pure ABS. PMMA/ABS alloy also improves surface gloss, suiting products with high appearance requirements.
Post-processing to strengthen the product surface is a common solution for high-wear scenarios.
Vacuum Coating Process
Using PVD (Physical Vapor Deposition) to apply a ceramic coating can increase the surface hardness of ABS products to HRC 50 or above, significantly improving wear resistance. It is used for high-end consumer electronics casings, though equipment costs are high.
Hard Coating Spraying
Spraying UV-curable hard coatings results in a pencil hardness of 3H-4H (meeting industry wear standards). The process is simple, suitable for large-scale production, and coating thickness can be adjusted to balance hardness and cost.
Surface Pretreatment Assistance
Chromate chemical treatment of the ABS product surface improves coating adhesion, preventing hard coating peeling during use and enhancing the durability of surface hardness.
Adjusting molding parameters can improve surface hardness without additional processes.
Molding Pressure and Temperature Adjustment
Moderately increasing the melt temperature (to 220-240℃) and raising the holding pressure by 10%-15% makes the surface material denser, reducing internal pores and indirectly improving surface hardness.
Mold Temperature Optimization
Controlling the mold temperature at 60-80℃ ensures uniform crystallization of the ABS melt on the cavity surface, reducing surface stress concentration and improving hardness consistency.
Molding Cycle Control
Shortening the cooling cycle prevents loose surface structure caused by rapid cooling, but cooling time must be balanced to avoid product deformation.
Current technologies for enhancing ABS surface hardness are moving toward environmental protection and intelligence: eco-friendly water-based UV hard coatings are replacing solvent-based ones to meet industrial emission requirements; intelligent modification systems use AI to regulate fiber dispersion, improving modification efficiency. In practice, material modification suits batch standardized products, surface treatment fits high-wear high-end products, and process optimization serves as a cost-saving auxiliary measure. A combination of solutions should be selected based on product positioning.
Enhancing the surface hardness of ABS products requires coordinated adjustments to material properties, production scale, and cost budgets through material modification, surface treatment, and process optimization. This effectively addresses low hardness issues while adapting to different product scenarios. With advancements in modification and coating technologies, the hardness performance and application scope of ABS products will continue to expand.
