Silicone seals are specialized sealing components made from silicone rubber—an elastomeric material celebrated for its exceptional resistance to extreme temperatures, старение, и химические вещества. Unlike traditional rubber seals (НАПРИМЕР., nitrile, Epdm), they balance flexibility, долговечность, and environmental safety, making them indispensable across industries from electronics to medical devices. This article breaks down their core properties, типы, сценарии применения, and selection criteria—with clear comparisons and practical tips to help you solve sealing challenges and ensure long-term performance.
1. Core Properties of Silicone Seals
Silicone seals’ unique advantages stem from their molecular structure, which combines silicon-oxygen bonds with organic side chains. Below are their non-negotiable traits, backed by actionable data:
| Свойство | Key Performance Metrics | Пример реального воздействия |
| Extreme Temperature Resistance | – Continuous use range: -50°C to +250°C.- Special formulations (НАПРИМЕР., high-temperature silicone) withstand short bursts of 300°C–350°C.- Поддерживает 90% elasticity after 1,000 часы при 200 ° C.. | An automotive engine silicone seal remains leak-free for 50,000+ км, even when exposed to 220°C exhaust heat—unlike nitrile seals, which harden and crack after 10,000 км. |
| Superior Aging Resistance | – Resists ozone, ультрафиолетовый (Укр) rays, and oxygen degradation.- No cracking or brittleness after 2,000 часов воздействия ультрафиолета (ASTM D1171 standard).- Служба срока службы: 5–10 years in outdoor applications. | A building’s silicone window seal shows no signs of wear after 8 years of rain, снег, and UV radiation—avoiding costly re-sealing projects. |
| Экологическая безопасность | – Нетоксичный, odorless, and compliant with global standards: – FDA 21 CFR 177.2600 (food contact). – Iso 10993 (Медицинская биосовместимость).- No harmful emissions (НАПРИМЕР., volatile organic compounds/VOCs). | A baby bottle silicone seal safely contacts milk at 100°C, with no chemical leaching—meeting parents’ safety expectations. A medical device seal (ISO 10993 сертифицирован) is used in surgical tools without causing tissue irritation. |
| Отличная электрическая изоляция | – Объемный удельное сопротивление: ≥10¹⁴ Ω·cm (при 25 ° C.).- Dielectric strength: ≥20 kV/mm (prevents electrical arcing).- Insulation performance unchanged at -40°C to 200°C. | A silicone seal in a power transformer insulates high-voltage components, even when the transformer reaches 180°C during peak load—avoiding short circuits. |
| Химическая совместимость | – Сопротивляется слабым кислотам (pH 4–10), щелочи, минеральные масла, и большинство растворителей (НАПРИМЕР., этанол, ацетон).- Swelling rate <5% после 7 days in engine oil (ASTM D471 standard). | A silicone O-ring in a chemical plant’s pipeline seals 98% уксусная кислота (pH 2.4) without swelling or leaking—unlike EPDM seals, which dissolve in acidic environments. |
2. Common Types of Silicone Seals
Silicone seals are categorized by shape and manufacturing process, each suited to specific sealing needs. Understanding these types ensures you match the right design to your application:
| Тип | Процесс производства | Ключевые преимущества | Идеальные приложения |
| Silicone O-Rings | Molded into circular rings (standard sizes: AS568, Iso 3601). | – Бюджетный, easy to install.- Seals static/dynamic gaps (НАПРИМЕР., вращающиеся валы).- Available in 1–50mm cross-sections. | – Hydraulic/pneumatic cylinders (static sealing).- Продовольственное оборудование (FDA-compliant variants).- Water faucets (leak prevention). |
| Silicone Gaskets | Extruded or molded into flat, custom shapes (НАПРИМЕР., прямоугольный, oval). | – Covers large surface areas (up to 1m × 1m).- Customizable thickness (0.5–10 мм).- Good compression set (≤15% after 70 hours at 150°C). | – Automotive door/window seals (noise reduction, water tightness).- Electronic device housings (НАПРИМЕР., TV back covers, Смартфон).- Industrial oven doors (high-temperature sealing). |
| Silicone Extrusions | Pushed through a die to create continuous profiles (НАПРИМЕР., T-shaped, U-shaped). | – Unlimited length (cut to size).- Complex cross-sections (НАПРИМЕР., multi-lip designs for enhanced sealing).- Fast production for large batches. | – Building curtain wall seals (air/water tightness).- Refrigerator door gaskets (temperature retention).- HVAC duct seals (energy efficiency). |
| Silicone Diaphragms | Molded into flexible, dome-shaped membranes. | – Controls fluid/gas flow (НАПРИМЕР., в насосах).- High tear resistance (≥30 kN/m).- Compatible with corrosive media. | – Chemical pump diaphragms (sealing acids/bases).- Компоненты топливной системы (ethanol-resistant variants).- Medical inhalers (precision flow control). |
Сравнение ключей: Для маленького, circular gaps (НАПРИМЕР., трубные суставы), silicone O-rings are the most cost-effective. Для большого, irregular surfaces (НАПРИМЕР., Автомобильные крышки двигателя), custom silicone gaskets provide superior coverage.
3. Application Scenarios by Industry
Silicone seals’ versatility makes them a staple across sectors where reliability and durability are critical. Below are their most common use cases:
| Промышленность | Specific Applications | Why Silicone Seals Are Irreplaceable |
| Автомобиль | – Engine gaskets (oil/coolant sealing).- Transmission seals (dynamic sealing for shafts).- EV battery seals (water/dust protection, управление температурным режимом). | Устойчивость к экстремальным температурам и химическому воздействию. (НАПРИМЕР., моторное масло, охлаждающая жидкость для электромобилей). Сократите затраты на техническое обслуживание за счет 30% против. традиционные резиновые уплотнители. |
| Электроника & Электрический | – Прокладки силового трансформатора (изоляция).- Уплотнения для светодиодных светильников (гидроизоляция, Степень защиты IP67/IP68).- Уплотнения для порта зарядки смартфона (пыленепроницаемость). | Электрическая изоляция предотвращает короткое замыкание.. Водонепроницаемость защищает чувствительные компоненты (НАПРИМЕР., Светодиодные драйверы) от повреждений. |
| Медицинский & Здравоохранение | – Уплотнения для хирургических инструментов (Совместимость стерилизации: автоклав, этиленоксид).- Пломбы для устройств доставки лекарств (НАПРИМЕР., Инсулиновые ручки).- Имплантируемые компоненты устройства (биосовместимые варианты). | Meet strict biocompatibility standards. Withstand repeated sterilization cycles (Нет деградации). |
| Еда & Напиток | – Food processing equipment gaskets (НАПРИМЕР., mixer seals).- Beverage bottle caps (leak prevention).- Oven/microwave door seals (heat retention). | FDA-совместимость, Нет химического выщелачивания. Resist high temperatures (НАПРИМЕР., 200°C in ovens) and frequent cleaning with harsh detergents. |
| Строительство | – Window/door seals (air/water tightness, sound insulation).- Curtain wall gaskets (structural bonding).- Roofing seals (weatherproofing). | Long service life (5–10 лет) reduces rework. UV/ozone resistance ensures performance in outdoor environments. |
4. Step-by-Step Guide to Choosing Silicone Seals
Selecting the right silicone seal avoids leaks, downtime, и риски безопасности. Follow this workflow to align the seal with your application:
4.1 Define Core Requirements
Start by answering these 4 questions to narrow down options:
- Температурная диапазон: What is the maximum/minimum temperature the seal will face? (НАПРИМЕР., -30°C to 180°C for a coffee machine seal).
- Media Contact: Will the seal touch liquids (масло, вода, химикаты), gases (воздух, кислород), or solids (еда, медицинские устройства)? (НАПРИМЕР., chemical compatibility is critical for a lab equipment seal).
- Sealing Type: Is it static (Нет движения, НАПРИМЕР., a door gasket) or dynamic (движущиеся части, НАПРИМЕР., a rotating shaft seal)? (Dynamic seals need low friction and high wear resistance).
- Стандарты Соответствие: Do you need FDA, Iso, or industry-specific certifications? (НАПРИМЕР., medical seals require ISO 10993; food seals need FDA 21 CFR 177.2600).
4.2 Select the Right Silicone Grade
Not all silicones are the same—choose a grade that matches your requirements:
| Silicone Grade | Ключевые черты | Идеально подходит для |
| General-Purpose Silicone | – Температурная диапазон: -50°C to 200°C.- Balanced elasticity and cost.- No special certifications. | Non-critical applications: toy seals, low-temperature storage gaskets. |
| Высокотемпературный силикон | – Температурная диапазон: -50°C to 300°C.- Reinforced with silica fillers for durability.- Низкая компрессия (≤10% at 200°C). | High-heat applications: прокладки двигателя, oven seals, industrial furnace components. |
| Food-Grade Silicone | – FDA 21 CFR 177.2600-compliant.- Нетоксичный, no odor.- Resists food oils and detergents. | Food contact: baby bottle seals, mixer gaskets, крышки напитков. |
| Medical-Grade Silicone | – ISO 10993 сертифицирован (биосовместимый).- Стерилизуется (автоклав, Гамма -радиация).- Low protein adsorption. | Медицинские устройства: surgical tool seals, insulin pen gaskets, имплантируемые компоненты. |
4.3 Выберите правильную форму & Размер
- O-Rings: Используйте стандартные размеры (НАПРИМЕР., AS568-214 for a 10mm inner diameter) для маленького, circular gaps. Для пользовательских размеров, provide inner diameter (ИДЕНТИФИКАТОР), Внешний диаметр (ИЗ), and cross-section (CS) размеры.
- Прокладки: Specify thickness (0.5–10 мм), длина, ширина, and any cutouts (НАПРИМЕР., для болтов). For large surfaces (НАПРИМЕР., 1m × 0.5m), opt for extruded gaskets (cost-effective for long lengths).
- Extrusions: Provide a 2D cross-section drawing (НАПРИМЕР., T-shaped, U-shaped) и длина. Complex profiles may require custom tooling (Время выполнения: 2–4 недели).
4.4 Verify Performance with Testing
Before full-scale deployment, test the seal against your application’s conditions:
- Compression Set Test: Ensure the seal rebounds after pressure (ASTM D395 standard—look for ≤15% set at your maximum operating temperature).
- Chemical Compatibility Test: Immerse the seal in your media (НАПРИМЕР., моторное масло) для 7 days—swelling rate should be <5%.
- Temperature Cycle Test: Expose the seal to 100 cycles of your minimum/maximum temperature (НАПРИМЕР., -50° C до 250 ° C.)—no cracking or leakage allowed.
5. Yigu Technology’s Perspective on Silicone Seals
В Yigu Technology, we’ve resolved countless sealing failures—most stem from choosing the wrong silicone grade or ignoring application conditions. A common mistake: Clients use general-purpose silicone for engine gaskets, leading to leaks after 6 месяцы. We always recommend high-temperature silicone (250°C+ resistance) for automotive under-hood applications, which extends seal life to 5+ годы. For food/medical clients, we emphasize traceability—each batch of FDA/ISO-certified seals includes a test report to avoid compliance risks. We also advise clients to consider compression set: A seal with 10% compression set at 200°C will outperform one with 20% set, even if both meet temperature requirements. Silicone seals aren’t just components—they’re reliability partners; investing in the right grade and shape saves time, деньги, and reputational damage.
6. Часто задаваемые вопросы: Common Questions About Silicone Seals
1 квартал: Can silicone seals be used in contact with gasoline or diesel?
А1: Standard silicone seals have limited resistance to hydrocarbons (бензин, дизель), which cause swelling (20%+ после 7 дни). For fuel contact, использовать fuel-resistant silicone (reinforced with fluorine or nitrile blends) or fluorosilicone seals—these have a swelling rate <5% in gasoline and are ideal for automotive fuel system applications (НАПРИМЕР., fuel tank gaskets).
2 квартал: How do I install silicone seals to avoid leaks?
А2: Следуйте этим 3 шаги: (1) Clean the sealing surface with isopropyl alcohol (remove oil, пыль, or old seal residue). (2) Apply a thin layer of silicone grease (compatible with your seal grade) to reduce friction and improve adhesion. (3) Compress the seal to 20%–30% of its original thickness (over-compression causes permanent deformation; under-compression leads to leaks). Например, a 5mm-thick gasket should be compressed to 3.5–4mm.
Q3: What is the service life of silicone seals, and how can I extend it?
А3: Service life varies by application: 5–10 years for outdoor/automotive seals, 3–5 years for high-heat (200° C+) уплотнения. Чтобы продлить жизнь: (1) Avoid over-exposure to 300°C+ temperatures (use high-temperature grades if needed). (2) Clean seals regularly with mild soap and water (избегайте агрессивных растворителей, таких как ацетон). (3) Store unused seals in a cool, сухое место (away from UV light) to prevent premature aging.