シリコンとゴムのどちらを選ぶべきでしょうか?

Silicone and rubber are essential raw materials in industrial manufacturing, daily life, and high-tech products. However, many designers struggle to select the appropriate material due to their significant performance differences. Choosing incorrectly may lead to product failure or cost inefficiencies. This article compares their core differences in material properties, applications, and selection criteria to guide informed decisions.

Material Properties: Heat Resistance, Environmental Impact

1.1 Composition and Environmental Friendliness

Silicone: Composed primarily of silicon dioxide (SiO₂), an inorganic polymer. Non-toxic, odorless, and meets food-grade standards after high-temperature vulcanization. Ideal for products in direct contact with humans (e.g., baby bottle nipples, kitchenware, pet slow-feed bowls).

Rubber: Includes natural rubber (derived from latex) and synthetic rubber (e.g., nitrile rubber, fluorocarbon rubber). Natural rubber is eco-friendly, but synthetic variants may contain chemical additives that release odors. Better suited for industrial uses like seals and gaskets.

1.2 Temperature Tolerance

Silicon: Exceptional range (-40°C to 260°C), with short-term resistance up to 350°C (e.g., hours). Perfect for high-temperature applications such as oven components and automotive engine seals.

Rubber: Standard types withstand up to 120°C; specialty rubbers (e.g., fluorocarbon) tolerate over 200°C but degrade under prolonged heat. Better for low-temperature environments.

1.3 Chemical Stability

Silicon: Resists acids, alkalis, and oxidation but performs poorly in oil-rich environments.

Rubber: Fluorocarbon and nitrile rubber excel in resisting oils, solvents, and corrosive media (e.g., acids/alkalis), making them ideal for chemical equipment seals.

Application Scenarios: Tailoring Material Choice

2.1 Electronics and Electrical Engineering

Silicone: Used for cable insulation and circuit encapsulation due to its electrical insulation and flexibility. Prevents cable tangling and vacuum collapse.

Rubber: Preferred for oil-resistant seals (e.g., fuel lines) but lacks strong electrical performance.

2.2 Automotive Industry

Silicon: Ensures reliable sealing in high-temperature parts like spark plug boots and radiator gaskets.

Rubber: Critical for tires and shock absorbers due to elasticity and wear resistance, but requires frequent replacement to avoid aging.

2.3 Medical and Food Industries

Silicone: Biocompatible for long-term implants (e.g., artificial heart valves) and sterilizable medical tools.

Rubber: Limited to short-term use (e.g., latex gloves) with potential allergy risks.

2.4 Aerospace and Extreme Environments

Silicon: Ablation-resistant variants protect rocket fuel valves; RTV silicone ensures spacecraft airtightness.

Rubber: Fluorocarbon rubber suits aviation hydraulics but hardens under sustained heat.

Selection Guide: Answer These Four Questions

Does the operating temperature exceed 200°C?

Yes → Silicon.

No → Choose rubber based on oil resistance needs.

Will it contact food or the human body?

Yes → Food-grade silicon.

No → Cost-effective rubber.

Is the environment oily or corrosive?

Yes → Fluorocarbon/nitrile rubber.

No → Silicon offers superior durability.

Is long-term aging resistance critical?

Yes → Silicon (10+ years).

No → Rubber (requires periodic replacement).

Future Outlook: Complementary Roles

With rising environmental standards, silicon is replacing rubber in consumer goods and electronics due to its non-toxicity, thermal stability, and ease of processing. However, rubber remains indispensable for oil resistance and low-cost applications. The future will see silicon dominating eco-friendly markets, while rubber retains industrial corrosion-resistant roles.

結論： The choice between silicon and rubber hinges on temperature, chemical exposure, lifespan, and cost—not just “soft vs. hard.” For tailored solutions, consult グランシャイン: Our engineering team provides expert guidance and manufacturing support.

Grandshine is a company with its own silicone mold making supplies, we have accumulated long-term manufacturing experience in silicon daily products and food grade silicone. We focus on providing our customers with custom made silicon molds solutions to meet their specific needs. We use a dust-free silicon production workshop, in strict compliance with ISO9001 and ISO14001 industry certification standards. All products must comply with Rohs, Reach standards, and FDA certification.

Grandshine has factory base in Shenzhen China and Johor Malaysia, we can provide product design to molding to mass production full supply chain service.  If you are looking for any silicon products or need to custom silicon mold, Grandshine is your best silicon products’ suppliers.