Surface Treatment for Automotive Interior Injection Molds
Surface treatment for automotive interior injection molds aims to enhance mold performance, improve product quality, and extend mold lifespan. Below are the primary methods and their applications:
Polishing
Objective:
To improve the cavity surface finish, meeting the aesthetic requirements for high-gloss interior components.
Methods:
Mechanical polishing, chemical polishing, or electrolytic polishing are used to achieve a refined mold surface.
Applications:
High-gloss interior components, such as decorative panels and dashboard covers.
Transparent or translucent plastic parts, such as interior light covers.
Precautions:
Avoid micro-scratches or ripples during polishing to ensure surface uniformity.
Use high-quality mold materials (e.g., S136, 718) to achieve better polishing results.
Texturing
Objective:
To create leather grain or special textures on interior components, enhancing the decorative appeal and anti-slip properties.
Methods:
Chemical etching, laser texturing, or sandblasting to produce textures on the mold surface.
Applications:
Components requiring leather textures, such as dashboards, door panels, and armrests.
Parts needing anti-reflective, tactile, or decorative effects.
Precautions:
Ensure uniform texture depth to avoid inconsistencies that may affect aesthetics.
Texture design should align with the overall style of the part to achieve cohesive visual effects.
Nitriding
Objective:
To improve mold hardness, wear resistance, and corrosion resistance by forming a nitrided layer on the surface.
Methods:
Gas nitriding or ion nitriding is applied to the mold cavity surface.
Applications:
Suitable for molds used in large-volume production of interior components.
Features:
Hardness can reach HV700–1200, significantly extending mold lifespan.
Low processing temperature ensures mold dimensions remain unchanged.
Chrome Plating
Objective:
To enhance mold surface hardness, corrosion resistance, and demolding performance.
Methods:
Hard chrome plating is used to form a high-hardness chrome layer on the mold surface.
Applications:
Molds for high-gloss or wear-resistant components, such as decorative parts and panels.
Mold cavity areas are prone to wear.
Features:
Smooth surface with high hardness and low friction coefficient.
Ideal for molds processing high-viscosity plastics, improving demolding efficiency.
PVD Coating (Physical Vapor Deposition)
Objective:
To enhance wear resistance, corrosion resistance, and demolding performance through a surface coating.
Methods:
In a vacuum environment, high-hardness materials are deposited on the mold surface using ion evaporation or sputtering techniques.
Applications:
Molds with complex structures or high-gloss products.
Long production cycles or molds are subject to high material wear.
Features:
Increases surface hardness, reduces friction and minimizes wear during injection molding.
Environmentally friendly with uniform and strong adhesion.
Sandblasting
Objective:
To improve surface roughness, achieve uniform matte effects or decorative textures.
Methods:
High-pressure spraying of metal or glass particles onto the mold surface.
Applications:
Molds for interior components requiring matte finishes or anti-slip functionality.
Precautions:
Particle size must be precisely controlled to avoid affecting product accuracy and quality.
Surface Hardening
Objective:
To increase mold surface hardness and wear resistance, reducing deformation and extending lifespan.
Methods:
Heat treatment, laser hardening, or other processes for targeted hardening of mold areas.
Applications:
Molds for high-volume production of interior components such as door panels and dashboards.
Corrosion Protection
Objective:
To prevent mold surface corrosion, particularly in high-humidity or high-temperature environments.
Methods:
Chemical nickel plating or applying anti-rust oil to the mold surface.
Using corrosion-resistant materials such as stainless steel or corrosion-resistant steels (e.g., S136).
Applications:
Molds processing specialty materials, such as flame-retardant or glass-fiber-filled plastics.
Laser Texturing
Objective:
To precisely create intricate decorative textures, enhancing visual and tactile appeal.
Methods:
Using laser engraving technology to produce high-precision patterns or leather textures on the mold surface.
Applications:
High-end automotive interior components, such as luxury car dashboards and seat trims.
Features:
High consistency in textures with flexible and customizable designs. Ideal for personalized demands.
