How does the rigidity of polypropylene compare to PVC for backrest support?

When evaluating materials for backrest support, rigidity is a critical factor. Polypropylene and PVC are two common polymers used in chair manufacturing, but they differ significantly in stiffness. Polypropylene is a semi-crystalline thermoplastic with moderate rigidity, offering flexibility and impact resistance. PVC, on the other hand, is generally stiffer due to its amorphous structure and higher density, providing firmer support for backrests.

Polypropylene's rigidity can be enhanced with fillers or reinforcements, but it typically remains less rigid than unmodified PVC. For applications requiring durable yet slightly flexible support, polypropylene may be preferable. PVC excels in scenarios demanding high rigidity and structural stability, though it may lack the resilience of polypropylene.

Ultimately, the choice depends on design requirements—polypropylene for balanced flexibility and comfort, or PVC for maximum rigidity and support. Both materials have distinct advantages, making them suitable for different backrest applications.