Injection Molding Office Chair Proportion
The proportions and materials of different components of injection-molded office chairs vary, as detailed below:
The headrest and back frame typically use PA material (nylon) reinforced with 30% fiber. PA, or polyamide, is a common engineering plastic known for its excellent mechanical properties, wear resistance, and chemical corrosion resistance. The addition of 30% fiber reinforcement significantly enhances its strength and rigidity, enabling the headrest and back frame to withstand substantial pressure and impact while maintaining good shape stability, meeting the long-term usage requirements of office chairs.
The lumbar support and armrests are made of high-molecular novel material TPEE. TPEE is characterized by its strong elasticity and flexibility, allowing the lumbar support to deform to a certain extent according to the curvature of the human back, providing good support and comfort, and effectively relieving lower back fatigue. When used for armrests, this material can also produce appropriate elastic deformation in response to arm pressure, enhancing comfort during use. Additionally, TPEE material has certain wear resistance and aging resistance, extending the service life of the lumbar support and armrests.
For PP plastic chairs, the formula is 100 parts of PP; 1 part of AC blowing agent; 0.8 parts of talc powder; 0.3 parts of white oil; and an appropriate amount of colorant. PP, or polypropylene, is a common thermoplastic known for its low density, high strength, and good heat resistance. The AC blowing agent causes the PP material to produce bubbles during the injection molding process, forming a porous structure that reduces the weight of the chair while maintaining a certain level of strength. The addition of talc powder improves the processing performance and dimensional stability of the PP material, while white oil acts as a lubricant, facilitating material flow and molding. The colorant can be adjusted according to needs to achieve different aesthetic colors for the chair.
High-strength nylon buckles commonly use PA66 (nylon 66) as the base material, reinforced with 30%-50% glass fiber, such as PA66 + 30%GF. PA66 has a high melting point, good mechanical strength, and heat resistance. The addition of glass fiber reinforcement further enhances its strength, rigidity, and heat resistance, enabling the buckles to withstand significant tensile and shear forces, ensuring a secure and reliable connection between the components of the office chair.
