What Is Silicone Rubber?
Silicone rubber is a type of polymer-based elastomer. Unlike many plastics, it is flexible, resilient, and chemically inert. Its most notable features include:
- High thermal resistance
- Waterproofing capabilities
- Flexibility
- Non-reactivity
- Excellent biocompatibility
These qualities make it ideal for products requiring long-term skin or food contact, such as baby bottle nipples, diving gear, kitchen utensils, and medical implants.
What Makes Silicone “Medical Grade”?
The term “medical-grade silicone” is frequently used in the industry, but its true definition depends on context. In general, there are two categories:
- Long-Term Implant Grade: This premium-grade silicone is designed for permanent internal use. Due to its ultra-high purity, it’s rarely used outside of medical implants, as it is cost-prohibitive for consumer products.
- Healthcare or Class VI Grade: This type undergoes strict biocompatibility testing and is suitable for prolonged contact with human tissue or food. TNSILICONE utilizes this standard in products such as menstrual cups, pacifiers, snorkel mouthpieces, and hydration systems.
Both categories typically rely on LSR for their manufacturing, given its ability to produce sterile, consistent components through injection molding.
Why Choose LSR?
LSR is supplied in a two-part system—one containing a catalyst, the other a crosslinker. This dual-pack format ensures consistent curing when pumped directly into molding machines.
Key Benefits:
- Stable mechanical properties
- Consistent quality output
- Minimal contamination risk
- Ideal for automation and high-volume production
Because of these advantages, LSR is the preferred material in many medical-grade applications.
How to Tell If Silicone is 100% Medical Grade?
Some products labeled as “medical grade” may still contain fillers. A quick test involves stretching the silicone by hand—if it turns white, it likely contains fillers. Pure medical-grade LSR should retain its transparency or original color, even under tension.
HCR (High Consistency Rubber) products, especially those with higher durometers (60–80 Shore A), often include fillers to increase hardness. While not inherently unsafe, this may impact biocompatibility depending on the application.
Understanding Silicone Curing Systems
The curing process transforms silicone from liquid to solid. This can occur via several systems:
1. Platinum-Catalyzed Curing
Used almost exclusively for LSR, this method produces medical-grade parts without requiring post-curing. TNSILICONE relies on platinum-cured LSR to ensure the highest material safety standards.
2. Peroxide Curing
More common in HCR silicone, this method is cost-effective but typically requires post-curing to remove volatile byproducts. Skipping this step can result in residual toxins, posing potential health risks.
3. Tin Condensation Curing
Not recommended for medical or food applications due to the residual presence of tin in the final product.
TNSILICONE focuses exclusively on injection molding of platinum-cured LSR and does not offer peroxide or extrusion-based solutions, ensuring the safest and most consistent results for healthcare products.
Silicone vs. Plastic: What Sets Them Apart?
Though silicone and plastic are both used for flexible products, there are significant differences:
- Longevity: Silicone lasts significantly longer, making it a sustainable alternative.
- Biocompatibility: It’s safer for food and body contact.
- Environmental Impact: Unlike plastics, silicone doesn’t produce microplastics.
- Thermal Resistance: Silicone can withstand high temperatures without leaching chemicals.
In terms of safety and environmental responsibility, silicone—particularly LSR—outperforms traditional materials like TPE or latex, especially in sensitive-use products.
Why Choose TNSILICONE?
With decades of experience in silicone product development, TNSILICONE is a global leader in LSR injection molding. Our engineering team supports clients across healthcare, consumer, and industrial markets, delivering high-quality components that meet the strictest regulatory standards.
Whether you are designing a next-generation medical device or looking to upgrade a consumer product with safer materials, our platinum-cured LSR solutions offer reliability, consistency, and peace of mind.
