Introduction
Isobutylene-Isoprene Rubber (IIR), material commonly known as Butyl Rubber, is a high-performance elastomer widely used in micro-molding applications requiring exceptional gas impermeability, weather resistance, and chemical durability. With its low permeability to air and gases, outstanding ozone resistance, and excellent resistance to polar solvents, IIR is a top choice for seals, gaskets, and barrier components in aerospace, medical, and industrial applications.
This article explores the benefits of Butyl Rubber micro-molding, key design considerations, and how engineers can optimize IIR for high-precision sealing applications.
Why Use Butyl Rubber for Micro-Molding?
Exceptional Gas Barrier Properties
- IIR has the lowest gas permeability among elastomers, making it ideal for airtight seals and vacuum applications.
- Used in aerospace and medical gas containment applications.
Superior Weather, Ozone & UV Resistance
- Outperforms Natural Rubber and SBR in outdoor and extreme-weather applications.
- Ideal for aerospace, marine, and outdoor industrial sealing components.
Excellent Chemical & Polar Solvent Resistance
- Highly resistant to polar solvents like alcohols, ketones, and acids.
- Used in medical and industrial fluid-handling systems.
Vibration & Impact Absorption
- Damps vibrations effectively, making it ideal for micro-sized isolators in aerospace and medical devices.
- Absorbs mechanical shocks in sensitive electronic and precision instruments.
Design Guidelines for Butyl Rubber Micro-Molding
1. Optimize Wall Thickness & Uniformity
- Recommended wall thickness: 0.3mm – 1.2mm for micro-seals and gaskets.
- Avoid sudden thickness changes to prevent shrinkage and stress points.
2. Maintain Tight Tolerances
- Standard tolerance: ±0.020mm for high-precision seals.
- Consider 1–2% material shrinkage in mold design.
3. Gas-Tight & Fluid-Sealing Surface Finishes
- Smooth, non-porous surfaces → Ideal for airtight seals.
- Micro-texturing can enhance adhesion in composite structures.
4. Gate & Flow Optimization
- Small, evenly distributed gates improve flow in thin-walled micro-molded IIR parts.
- Proper venting is critical to prevent voids and gas entrapment in barrier seals.
Applications of Butyl Rubber Micro-Molding in High-Precision Seals
- Aerospace & Defense – Micro-seals for fuel tanks, vacuum systems, and high-altitude pressure containment.
- Medical Devices – Sterile pharmaceutical stoppers, gas-tight seals, and chemical-resistant gaskets.
- Industrial Equipment – Air-tight gaskets for pipelines, compressors, and gas-handling systems.
- Automotive & Marine – Vibration isolators and weatherproof seals for extreme conditions.
Butyl Rubber micro-molding is the go-to solution for high-precision, gas-impermeable seals and barrier components. With its exceptional weather resistance, chemical durability, and airtight performance, IIR is widely used in aerospace, medical, and industrial sealing applications.
In need of Butyl Rubber (SBR) Parts?
If you’re designing precision micro-molded IIR components, consult with rubber processing experts to optimize material selection and mold design for your specific needs.
Contact us to learn more.
