Silicone/Rubber Extruded Seal Strip
Product Introduction
What Are Extruded Seals?
Extruded seals are continuous lengths of elastomeric material formed by pushing raw compound through a shaped die. The result is a uniform profile, ideal for sealing doors, windows, panels, or machinery enclosures.
They are widely used in:
Automotive door and window sealing
HVAC systems
Construction and glazing applications
Medical and food-grade environments
Common Materials Used in Extruded Seals
1. Silicone Rubber
Silicone is one of the most popular choices due to its excellent temperature resistance (-60°C to +230°C), UV stability, and non-toxic, food-grade options. It's widely used in:
Medical devices
Food packaging equipment
Outdoor electrical enclosures
2. EPDM Rubber
Ethylene Propylene Diene Monomer (EPDM) is known for its superior weather resistance, making it ideal for:
Automotive door seals
Roofing systems
HVAC duct seals
3. Nitrile Rubber (NBR)
NBR excels in oil nd fuel resistance and is often found in:
Automotive fuel systems
Industrial equipment seals
4. PVC (Polyvinyl Chloride)
PVC is often used in low-cost applications. While it’s not as flexible or weather-resistant as silicone or EPDM, it's still a good choice for light-duty sealing, insulation, and decorative trims.
Functional Benefits of Silicone & Rubber Extruded Seals
Sealing: Prevents air, dust, and water ingress.
Shock Absorption: Provides cushioning in mechanical assemblies.
Thermal & Acoustic Insulation: Reduces energy loss and noise.
Vibration Damping: Protects delicate equipment from vibration damage.
These features are essential in industries like automotive, aerospace, electronics, and construction—explaining the frequent search terms like “rubber gasket extrusion for cars” or “weatherproof rubber sealing strips”.
Performance Characteristics
|
Property |
Silicone |
EPDM |
Nitrile (NBR) |
PVC |
|
Temperature Resistance |
Excellent (-60°C to +230°C) |
Good (-50°C to +130°C) |
Moderate (-40°C to +120°C) |
Limited (-20°C to +60°C) |
|
UV/Ozone Resistance |
Excellent |
Excellent |
Poor |
Poor |
|
Flexibility |
Excellent |
Good |
Moderate |
Low |
|
Chemical Resistance |
Good |
Good (esp. water, alkalis) |
Excellent (oils/fuels) |
Limited |
|
Food-Grade Options |
Yes |
No |
No |
No |
|
Cost |
Higher |
Moderate |
Moderate |
Low |
Note: PVC is more brittle in cold weather and has lower elasticity, making it less reliable for dynamic sealing applications compared to silicone and rubber.
The Production Process: How Rubber Seals Are Made
The production of silicone and rubber extruded seals involves several precise steps:
Material Compounding
Raw silicone or rubber is mixed with additives (colorants, stabilizers, vulcanizing agents) to enhance performance.
Extrusion
The compound is pushed through a custom die to create a specific profile (e.g., D-shaped, P-shaped, hollow tubes, etc.)
Curing or Vulcanization
The extruded material is cured using heat (hot air oven or salt bath), which strengthens the seal and gives it long-term flexibility.
Post-Processing
Includes cutting to length, adhesive backing, hole punching, or joining into rings or frames.
Quality Control
Ensures consistent dimensions, hardness, compression set, and appearance.
Choosing the Right Material for Your Project
When selecting a sealing solution, consider:
Application Environment: High temperature? Outdoor use? Contact with chemicals?
Flexibility Requirements: Will the seal bend frequently or stay static?
Certifications: FDA-grade? UL-listed? RoHS compliant?
For example, a custom rubber extrusion for a medical device may demand platinum-cured silicone, whereas a weather strip for an automotive door might use EPDM for its ozone resistance.
Silicone and rubber extruded seals are indispensable in modern product design due to their adaptability, durability, and wide range of material options. Understanding the differences between silicone, rubber, and PVC is key to choosing the right material for your sealing needs.
When in doubt, consult a rubber extrusion manufacturer or custom sealing solution provider who can guide you through material selection, profile design, and production.