Silicone sealants are high-performance elastomeric materials based on polydimethicone (PDMS). By blending PDMS with crosslinkers, наполнители, and catalysts, they cure into flexible, durable sealing layers—either at room temperature or with heat. Their exceptional weather resistance, химическая стабильность, and adhesion make them indispensable across industries. But how do you classify them, choose the right type for your project, и избегать общих ошибок?
1. Classification of Silicone Sealants: A Clear Comparison
Silicone sealants are categorized by three core factors: component, curing mechanism, and function. The table below simplifies these classifications to help you identify the right fit:
| Classification Basis | Тип | Ключевые характеристики | Идеальные варианты использования |
| By Component | Single-component | No mixing needed; cures by absorbing air moisture; простой в использовании | Quick repairs (НАПРИМЕР., home sink waterproofing), small-area construction (НАПРИМЕР., glass fish tank gluing) |
| Two-component | Requires mixing Component A (silicon hydroxyl group) и Component B (silane crosslinker); deep curing ability | Large-scale engineering (НАПРИМЕР., curtain wall sealing), high-demand projects (НАПРИМЕР., high-temperature pipe joints) | |
| By Curing Mechanism | Condensation-type | Releases small-molecule by-products (НАПРИМЕР., этанол) во время отверждения; needs ventilation | Общее строительство (НАПРИМЕР., concrete expansion joints), non-food/medical scenarios |
| Additive-type | No by-products; экологически чистый; соответствует строгим стандартам безопасности | Food-grade applications (НАПРИМЕР., food machinery sealing), медицинские устройства (НАПРИМЕР., skin-contact parts) | |
| By Functional Feature | General-purpose | Balanced basic properties (adhesion, Гибкость) | Daily home maintenance (НАПРИМЕР., sanitary ware installation) |
| Пламя-возобновляющий | Passes fire safety tests; inhibits combustion | Электрическое оборудование (НАПРИМЕР., circuit board coating), building fire barriers | |
| Thermally conductive | Transfers heat efficiently; maintains insulation | Электронные компоненты (НАПРИМЕР., heat sink gaskets) | |
| Высокая сила | Superior tensile and shear resistance | Structural joints (НАПРИМЕР., automotive body welds) | |
| Low-volatility | Minimal volatile organic compounds (Вокал) | Indoor sensitive environments (НАПРИМЕР., hospital operating rooms) |
2. Core Performance Characteristics: Why Silicone Sealants Stand Out
What makes silicone sealants superior to other sealing materials (НАПРИМЕР., акрил, полиуретан)? Their performance advantages are rooted in their chemical structure, Как показано ниже:
- Broad-Spectrum Temperature Resistance: Withstands extreme temperatures from -60°C to +250°C (short-term up to 300°C). This makes them ideal for outdoor pipelines, engine compartments, and other high/low-temperature alternating environments—unlike acrylic sealants, which crack at -20°C.
- Long-Lasting Aging Resistance: Resists UV radiation, ozone, влага, and salt spray. In outdoor applications (НАПРИМЕР., занавесные стены), their service life exceeds 10 годы—far longer than polyurethane sealants (3–5 лет).
- Reliable Electrical Insulation: Boasts a high breakdown voltage (>20kV/mm) и стабильная диэлектрическая проницаемость. Защищает электрические компоненты (НАПРИМЕР., Трансформеры) от влаги и пыли без ущерба для изоляции.
- Сбалансированная гибкость & Адгезия: После лечения, он поддерживает регулируемый Береговая твердость (20–80А) и выдерживает до 500% удлинение без растрескивания. Он прочно сцепляется с металлами., стекло, керамика, и пластмассы — даже при тепловом расширении или вибрации.
- Биосовместимость: Силиконовые герметики медицинского класса соответствуют стандартам FDA., поддержка контакта с кожей и кратковременная имплантация (НАПРИМЕР., прокладки медицинского устройства). Ни один другой распространенный герметик не предлагает такого сочетания безопасности и производительности..
3. Step-by-Step Application Guide: Ensure Success Every Time
Improper application can ruin even the best silicone sealant. Follow this linear, easy-to-follow process to achieve a durable seal:
Шаг 1: Подготовка поверхности (Critical for Adhesion)
- Clean the substrate (металл, стекло, и т. д.) with a solvent (НАПРИМЕР., ацетон) удалить масло, пыль, and release agent residues.
- Dry the surface completely—moisture on non-porous substrates (НАПРИМЕР., стекло) will weaken adhesion.
- For low-adhesion substrates (НАПРИМЕР., some plastics), apply a special primer and let it dry for 15–30 minutes before applying the sealant.
Шаг 2: Sealant Application (Control Thickness & Форма)
- Load the sealant into a caulking gun. For single-component types, cut the nozzle at a 45° angle to match the joint width.
- Apply the sealant in a continuous, even bead. А single-application thickness should not exceed 6mm—thicker layers will not cure completely internally, leading to soft spots.
- Use a tool (НАПРИМЕР., a silicone smoothing tool) to shape the bead within 5–10 minutes (before surface curing) for a neat finish.
Шаг 3: Выклятый & Post-Care (Избегайте общих ловушек)
- Let the sealant cure in a well-ventilated area. Примечание: High humidity speeds up surface drying but slows deep curing—allow 24–48 hours for full curing (longer in cold/dry conditions).
- Avoid touching or disturbing the sealant during curing.
- Clean up uncured sealant with acetone; cured sealant must be cut or scraped off.
4. Руководство по выбору: Match Sealant to Your Exact Needs
Choosing the wrong silicone sealant wastes time and money. Use this table to align the product with your scenario:
| Demand Scenario | Recommended Sealant Type | Key Performance Indicators to Check |
| Interior decoration (НАПРИМЕР., оконные рамы, sanitary ware) | Neutral single-component | Non-corrosive, Низкий запах, Shore hardness 30–50A |
| High-temperature pipe sealing (НАПРИМЕР., industrial boilers) | High-modulus two-component (additive-type) | Теплостойкость >200° C., предел прочности >3МПА |
| Электронные компоненты (НАПРИМЕР., круговые платы, датчики) | Additive flame-retardant grade | CTI insulation rating ≥600V, flame retardancy UL94 V-0 |
| Food machinery repair (НАПРИМЕР., конвейерные ремни, tank joints) | FDA-certified transparent | Complies with GB/T national food safety standards, no VOCs |
| Outdoor construction (НАПРИМЕР., занавесные стены, roof joints) | Weather-resistant two-component | Ультрафиологическое сопротивление >10 годы, salt spray resistance >5000 часы |
5. Common Misconceptions: Debunking Myths
Many users make mistakes due to false assumptions. Below are three key myths and the facts:
- Миф 1: “All silicone sealants are high-temperature resistant.”
Факт: Temperature resistance depends on the formula. Normal-grade sealants only work below 80°C—only high-temperature grades (НАПРИМЕР., phenyl silicone-based) handle 200°C+.
- Миф 2: “Acid glass glue = silicone sealant.”
Факт: Acidic glass glue is a type of silicone sealant but contains acetic acid. It is highly corrosive and cannot be used on metals (causes rust) or marble (etches surfaces). Choose neutral silicone for these substrates.
- Миф 3: “Thicker application = better sealing.”
Факт: Excessive thickness (>6мм) causes incomplete internal curing, leading to poor durability. For wide joints, apply multiple thin layers (allowing each to cure partially) вместо.
6. Yigu Technology’s Perspective on Silicone Sealants
В Yigu Technology, we view silicone sealants as “invisible protectors” for infrastructure and products. Для автомобильных клиентов, наш high-strength two-component sealants reduce body weld corrosion by 80% and withstand engine compartment temperatures up to 250°C. For medical device manufacturers, наш FDA-certified additive-type sealants meet strict biocompatibility standards, supporting safe skin contact and short-term implantation.
Заглядывая в будущее, we will focus on two innovations: 1) Developing low-VOC eco-friendly sealants to cut carbon emissions by 25% и 2) Enhancing the thermal conductivity of electronic-grade sealants to improve heat dissipation efficiency by 30%. Our goal is to make silicone sealants more sustainable, надежный, and tailored to industry-specific needs.
Часто задаваемые вопросы
- How long does silicone sealant take to fully cure, and what affects curing time?
Full curing takes 24–48 hours under standard conditions (25° C., 50% влажность). High humidity accelerates surface drying but slows deep curing; низкие температуры (<10° C.) extend curing time to 72+ часы. Always check the product datasheet for specific times.
- Can silicone sealant be painted over, and if so, как?
Most silicone sealants are non-paintable due to their smooth surface. For paintable needs, choose “paintable silicone sealants” (formulated with special additives). Ждать 72 hours for full curing, then use acrylic or latex paint—avoid oil-based paints (they peel off).
- How to store unused silicone sealant to extend its shelf life?
Seal the nozzle tightly (use a cap or tape) and store in a cool, сухое место (5–25 ° C.) away from heat sources and strong oxidants. Unopened single-component sealants have a shelf life of 12 месяцы; opened ones should be used within 1 месяц. Two-component sealants must be stored separately to prevent premature curing.