Office chair plastic armrests are usually made of glass fiber reinforced PP, modified nylon (PA+GF) or ABS engineering plastics, which combine high strength, impact resistance and lightweight, ensuring that they are not easily deformed or cracked after long-term use.
1. Glass Fiber Reinforced PP: A Mainstream, High-Performance Material
Core Advantages: Adding 10%–30% glass fiber to polypropylene (PP) significantly improves rigidity and creep resistance, increasing load-bearing capacity by more than twice that of ordinary plastics.
Applicable Scenarios: Commonly used in mid-range office chairs, suitable for high-frequency use environments such as daily office work and meetings. It has a wide temperature resistance range (-20℃~120℃) and is not easily deformed by temperature changes.
Production Ease: High injection molding efficiency, no secondary processing required. The surface can be directly treated with frosting or texturing to enhance texture and slip resistance.
2. ABS Engineering Plastic: Balancing Texture and Cost
Comprehensive Performance: Copolymerized from acrylonitrile, butadiene, and styrene, it combines hardness, toughness, and surface gloss. Commonly used for armrest shells or decorative parts.
Usage Characteristics: Smooth to the touch, easy to spray or electroplate, enhancing the overall appearance. However, prolonged exposure to sunlight may cause aging and brittleness; direct sunlight should be avoided.
Common pairings: mostly used in mid-to-low-end office chairs or as a surface covering for armrests, while the internal structure is still mainly supported by nylon or PP.
3.Modified Nylon (PA+GF): High Strength and Durability First Choice
Material Characteristics: Based on PA6 or PA66, reinforced with glass fiber, it boasts three major advantages: high impact resistance, wear resistance, and fatigue resistance, making it suitable for high-intensity use.
Structural Performance: Maintains stability under repeated adjustments and stress, commonly found in high-end ergonomic chairs such as the Herman Miller and Sihoo M57 models.
Environmental Adaptability: Possesses some moisture absorption, but this does not affect performance in normal office environments. It also has a higher flame retardant rating and meets BIFMA safety standards.
2. Other Auxiliary Materials and Surface Treatments
PU Wrapping: Some high-end armrests have a polyurethane (PU) coating over the plastic base material, enhancing softness and reducing pressure on the arms, especially suitable for long periods of desk work.
Metal Core Reinforcement: To improve the stability of the adjustment mechanism, some movable armrests incorporate steel rails or aluminum alloy supports, then are covered with a plastic shell, achieving a "soft exterior, rigid interior" structure.
Anti-slip texture design: The surface is embossed with anti-slip textures or uses soft rubber patches to enhance friction, prevent hand slippage, and improve operational stability.