1. Material Composition and Properties
Liquid Silicone Rubber (LSR):
Base Material: Silicone polymer with a cross-linked molecular structure.
Flexibility: Retains elasticity across a wide temperature range (-50°C to +200°C).
Durability: Resistant to UV radiation, ozone, and extreme temperatures.
Biocompatibility: Non-toxic and hypoallergenic, making it ideal for medical devices.
PVC (Polyvinyl Chloride):
Base Material: Synthetic thermoplastic polymer.
Rigidity/Flexibility: Rigid by default but can be softened with plasticizers (e.g., phthalates).
Temperature Resistance: Limited to -20°C to +60°C; degrades at higher temperatures.
Chemical Resistance: Resists acids, oils, and alkalis but may release harmful fumes when burned.
2. Key Differences Between LSR and PVC
A. Temperature Resistance
LSR: Excels in extreme environments. Stable in both high-heat (e.g., automotive engines) and cryogenic conditions.
PVC: Softens or deforms above 60°C, limiting its use in high-temperature applications.
B. Chemical and Environmental Stability
LSR: Highly resistant to oxidation, UV exposure, and chemicals. Does not degrade outdoors.
PVC: Vulnerable to UV degradation over time. Plasticizers can leach out, causing brittleness.
C. Safety and Compliance
LSR: FDA-approved, biocompatible, and odorless. Safe for food-grade and medical products.
PVC: Contains additives (e.g., phthalates) that may pose health risks. Requires careful regulation for food/medical use.
D. Manufacturing Process
LSR: Liquid injection molding (LIM) enables precision for complex geometries and thin walls.
PVC: Extrusion or injection molding; requires additives for flexibility, increasing production complexity.
E. Cost Considerations
LSR: Higher upfront material cost but offers long-term durability and reduced replacement frequency.
PVC: Lower initial cost but may degrade faster, leading to higher lifecycle expenses.
3. Applications: Where to Use LSR vs. PVC
LSR Applications:
Medical: Seals, gaskets, baby bottle nipples, and implants.
Automotive: Gaskets, hoses, and vibration-resistant components.
Consumer Electronics: Waterproof seals, keypads, and wearables.
PVC Applications:
Construction: Pipes, window frames, and flooring.
Electronics: Cable insulation and wiring sheathing.
Household Items: Shower curtains, inflatable products, and synthetic leather.
4. Sustainability and Environmental Impact
LSR: Recyclable and generates minimal waste during production. Non-toxic decomposition.
PVC: Recycling is challenging due to additives. Burning releases toxic dioxins, raising environmental concerns.
Conclusion: Which Material Should You Choose?
Choose LSR for high-performance, safety-critical applications requiring durability and biocompatibility.
Opt for PVC for cost-sensitive, short-term projects where flexibility and chemical resistance are sufficient.
By understanding these differences, businesses can optimize product design, reduce costs, and meet regulatory standards.