High-temperature silicone is a specialized elastomeric material engineered to withstand extreme thermal conditions while retaining critical properties like elasticity, Chemische Stabilität, and insulation. Unlike standard silicone (which typically maxes out at 150°C), it thrives in environments ranging from -60°C to 300°C (with some grades handling short bursts of 350°C+), making it indispensable for industrial sealing, mold manufacturing, and electronic protection. In diesem Artikel werden seine Kernmerkmale aufgeschlüsselt, classifications, Anwendungsszenarien, and step-by-step usage guidelines—with clear comparisons and practical tips to help you select and apply it correctly.
1. Core Characteristics of High-Temperature Silicone
High-temperature silicone’s value stems from a unique combination of thermal and mechanical properties that outperform standard silicone and other elastomers. Below are its non-negotiable traits, backed by actionable data:
| Merkmal | Key Performance Metrics | Beispiel für reale Auswirkungen |
| Exceptional Thermal Resistance | – Continuous use range: -60°C to 300°C.- Short-term peak resistance: 350° C (special grades).- Pflege 80% of elasticity after 1,000 hours at 250°C. | An automotive engine gasket made from high-temperature silicone remains flexible and leak-free, Auch danach 500+ hours of exposure to 220°C exhaust heat—unlike standard silicone, which hardens and cracks after 100 Std.. |
| Wetter & Umweltdauer | – Resists UV degradation (no brittleness after 2,000 hours of sunlight).- Withstands ozone, Feuchtigkeit, and salt spray (passes 500-hour salt fog tests). | A high-temperature silicone seal for outdoor industrial ovens shows no signs of cracking or discoloration after 1 year of exposure to rain, UV -Strahlen, und Temperaturschwankungen (-10°C to 280°C). |
| Chemische Stabilität | – Resists corrosion from weak acids (pH 4–10), Alkalis, Mineralöle, und die meisten Lösungsmittel (Z.B., Ethanol, Aceton).- Compliant with FDA 21 CFR 177.2600 (food-grade variants). | A food-grade high-temperature silicone baking mold safely endures repeated exposure to 220°C oven heat and cleaning with harsh dish soap—no chemical leaching or material degradation. |
| Elektrische Isolierung | – Volumenwiderstand: ≥10¹⁴ Ω·cm (at 250°C).- Dielectric strength: ≥20 kV/mm (prevents electrical arcing). | High-temperature silicone potting compound protects LED driver modules in industrial lighting, maintaining insulation integrity even when the module reaches 180°C during operation. |
| Mechanical Flexibility | – Land eine Härte: 20–60 (Einstellbar für bestimmte Bedürfnisse).- Dehnung in der Pause: ≥300% (handles thermal expansion/contraction). | A high-temperature silicone O-ring for a boiler pipe expands and contracts with temperature changes (100°C to 280°C) without leaking—its flexibility prevents stress cracks. |
2. Classification of High-Temperature Silicone
High-temperature silicone is categorized by two key factors: curing mechanism (how it hardens) and end-use (what it’s designed to do). Understanding these categories ensures you select the right grade for your project.
2.1 By Curing Mechanism
| Typ | Härtungsmittel & Verfahren | Schlüsselvorteile | Nachteile | Ideal für |
| Zusatzstoff (Platinum-Cure) Hochtemperatur-Silikon | Cured with platinum catalysts; no byproducts released during curing. | – Umweltfreundlich (geruchlos, no toxic emissions).- Niedriger Schrumpfung (0.1–0,5%)—critical for precision molds.- Hervorragende Transparenz (for optical applications). | – Höhere Kosten (20–30% more than condensation types).- Sensitive to contamination (Z.B., sulfur ruins curing). | Präzisionsformen (Z.B., semiconductor component molds), food-grade applications (Backformen), and optical parts (light diffusers). |
| Condensation High-Temperature Silicone | Cured with tin catalysts; releases small byproducts (Z.B., Ethanol, Essigsäure) Während der Heilung. | – Niedrigere Kosten (budget-friendly for large-volume use).- Less sensitive to contamination.- Faster room-temperature curing (12–24 hours vs. 24–48 hours for additive). | – Mild odor (fades after curing).- Higher shrinkage (1–2%)—not for precision parts.- Byproducts may corrode sensitive metals (Z.B., Kupfer). | General industrial sealing (pipe gaskets), non-precision molds (rubber vulcanization molds), and low-cost repair projects (metal crack sealing). |
2.2 Nach Endverwendung
| Typ | Bilden & Schlüsseleigenschaften | Anwendungsbeispiele |
| High-Temperature Sealant | Paste or liquid form; cures to a flexible elastomer. | – Boiler pipe joints (prevents high-temperature gas leakage).- Ovens and furnaces (door seals, heating element gaskets).- Automotive exhaust systems (manifold gaskets). |
| High-Temperature Mold Adhesive | Flowable liquid; designed to capture fine details in molds. | – Die-casting molds (for metal alloys like aluminum).- Rubber vulcanization molds (for automotive hoses).- Food-grade baking molds (cake pans, chocolate molds). |
| High-Temperature Electronic Potting Compound | Viscous liquid; cures to a rigid or flexible solid (einstellbar). | – Potting LED drivers, Transformatoren, and power modules (protects from heat and moisture).- Encapsulating sensors in industrial machinery (withstands 250°C+). |
| High-Temperature Sheet Silicone | Pre-cured sheets (0.5–10 mm dick); ready to cut and use. | – Gaskets for industrial ovens and fryers.- Insulation pads for electronic components (Z.B., CPU heat sinks).- Seals for aerospace ducting (withstands 300°C). |
3. Wichtige Anwendungsszenarien
High-temperature silicone’s versatility makes it a staple across industries where heat, Chemikalien, or environmental stress are constant challenges.
| Industrie | Specific Use Cases | Why High-Temperature Silicone Is Irreplaceable |
| Industrielle Fertigung | – Boiler/furnace seals and gaskets.- Die-casting molds for metal parts.- Potting for industrial sensors (Z.B., temperature probes). | Withstands continuous exposure to 250°C–300°C; resists corrosion from industrial oils and cleaning solvents. |
| Automobil & Luft- und Raumfahrt | – Engine gaskets (Ölpfannen, Auspuffkrümmer).- Aerospace ducting seals (300° C+).- Battery pack insulation (Elektrofahrzeuge). | Handles thermal cycling (from -40°C to 280°C) ohne Abbau; leicht (reduces vehicle/aerospace weight). |
| Essen & Getränk | – Backformen (cookies, bread).- Food processing equipment seals (Z.B., Förderbänder).- Microwave-safe cookware liners. | FDA-konform (Kein chemisches Auslaugen); withstands 220°C–250°C oven/microwave heat. |
| Elektronik | – LED driver potting (high-power LEDs).- Transformer insulation.- Circuit board conformal coating (protects from heat/moisture). | Maintains electrical insulation at 180°C+; prevents short circuits from thermal expansion. |
| Heim & DIY | – High-temperature repair (metal pipe cracks, ceramic tile fixes).- Grill/searing pan gaskets.- Homemade candle molds (heat-resistant to wax melting). | Easy to apply (Aushärtung bei Raumtemperatur); no specialized tools needed for small projects. |
4. Schritt-für-Schritt-Anleitung zur Verwendung von Hochtemperatursilikon
Proper application ensures high-temperature silicone performs as intended. Follow this workflow for sealing, Schimmelherstellung, or potting:
4.1 Vorbereitung (Kritisch für den Erfolg)
- Oberflächenreinigung:
- Wipe the target surface (Z.B., pipe joint, Schimmelpilzrahmen) mit Isopropylalkohol (70–90 %) Öl entfernen, Staub, or rust. For metal surfaces, use a wire brush to remove corrosion—contaminants prevent adhesion.
- Werkzeug & Materialvorbereitung:
- Werkzeuge sammeln: electronic scale (±0.1g), stir rod (glass/plastic), Trennmittel (petroleum jelly for molds), and a vacuum degassing machine (for precision applications).
- Verify the silicone grade: Ensure it matches your temperature needs (Z.B., 300°C for oven seals) and compliance requirements (Z.B., FDA for food use).
4.2 Mischen (Vermeiden Sie Fehler bei der Behebung)
- Ratio Accuracy:
- Follow the manufacturer’s ratio (Z.B., 10:1 for condensation silicone, 1:1 for additive silicone). Use an electronic scale—even a 1% error (Z.B., 100:4 anstatt 100:5) causes incomplete curing.
- Bubble Removal:
- Stir slowly in one direction (2–3 Minuten) to avoid trapping air. For molds or potting, use a vacuum degassing machine (-0.1MPA) for 1–2 minutes—bubbles in the silicone cause leaks or voids.
4.3 Anwendung (Auf den Endverbrauch zugeschnitten)
| Anwendungsfall | Application Steps | Tipps für den Erfolg |
| Versiegelung (Pipes/Ovens) | 1. Apply silicone in a continuous bead along the gap (3–5mm thick).2. Use a spatula to smooth the bead and ensure full contact.3. Let cure per instructions. | – Avoid over-applying (wastes material).- For vertical surfaces, apply from bottom to top to prevent sagging. |
| Schimmelherstellung | 1. Apply release agent to the prototype (Z.B., petroleum jelly for wax models).2. Pour silicone over the prototype (tilt the mold frame to reduce bubbles).3. Cure fully before demolding. | – Für komplexe Prototypen, use a split mold design (avoids tearing).- Extend curing time by 50% for thick molds (>10mm). |
| Electronic Potting | 1. Place the component (Z.B., LED driver) in a potting box.2. Pour silicone to fully cover the component (1–2mm extra for protection).3. Cure at room temperature or accelerate with heat. | – Use a low-viscosity grade (flows into small component gaps).- Avoid trapping air around sensitive parts (Z.B., Kondensatoren). |
4.4 Heilung & Nachbearbeitung
- Curing Conditions:
- Room-temperature curing: 24–48 Stunden (condensation silicone: 12–24 Stunden; additive silicone: 24–48 Stunden).
- Accelerated curing: Heat at 60–100°C (reduces time by 50%, Z.B., 24 hours → 12 Std.). Do not exceed 120°C (may cause brittleness).
- Nachbearbeitung:
- Nach dem Heilung, trim excess silicone with a sharp knife. For food-grade applications, wash the surface with warm soapy water and air-dry (removes any residual curing agents).
5. Wichtige Vorsichtsmaßnahmen zur Vermeidung von Ausfällen
Even high-quality high-temperature silicone fails if misused. Befolgen Sie diese Regeln:
- Kontaminationskontrolle:
- Zusatzstoff (platinum-cure) silicone is sensitive to sulfur, Zinn, and certain oils (Z.B., motor oil)—keep it away from rubber gloves, Schmierstoffe, or sulfur-containing materials (ruins curing).
- For condensation silicone, avoid contact with copper or brass (byproducts cause corrosion).
- Temperature Limits:
- Do not exceed the silicone’s continuous use temperature (Z.B., a 300°C grade should not be used long-term at 350°C). Short bursts of peak temperature are safe only if specified by the manufacturer.
- Lagerung:
- Unopened silicone: Store in a cool, Trockener Ort (15°C–25°C) weg vom direkten Sonnenlicht. Shelf life: 6–12 Monate (additive silicone); 12–24 Monate (condensation silicone).
- Opened silicone: Seal tightly after use—moisture absorption degrades performance.
- Sicherheit:
- In einem gut belüfteten Gebiet arbeiten (condensation silicone releases mild fumes during curing).
- Wear nitrile gloves and safety goggles (uncured silicone may irritate skin/eyes).
6. Die Perspektive von Yigu Technology zu Hochtemperatursilikon
Bei Yigu Technology, we’ve seen high-temperature silicone solve critical challenges for clients—from automotive manufacturers to food processors. A common mistake we address is choosing the wrong curing type: one client used condensation silicone for a precision semiconductor mold, ergebend 2% Schwindung (ruining part fit). We switched them to additive silicone (0.3% Schwindung), which fixed the issue and reduced rework costs by 40%. Für Projekte für Lebensmittel, we always recommend platinum-cure variants (FDA-konform, Kein Geruch) over condensation types. We also emphasize vacuum degassing for mold applications—this eliminates 95% of bubbles that cause leaks in high-temperature seals. High-temperature silicone isn’t just a material—it’s a reliability tool; selecting the right grade and following proper application steps ensures long-term performance, even in extreme environments.
7. FAQ: Häufige Fragen zu Hochtemperatursilikon
Q1: Wird Hochtemperatursilikon in kalten Umgebungen aushärten oder spröde werden? (Z.B., -60° C)?
A1: High-temperature silicone retains flexibility down to -60°C—unlike standard rubber, which becomes brittle below 0°C. It may feel slightly stiffer in cold temperatures but returns to full elasticity when warmed to room temperature. Zum Beispiel, a high-temperature silicone O-ring for a freezer-to-oven conveyor belt remains functional at -40°C and 280°C without cracking.
Q2: Kann ich Hochtemperatursilikon auf andere Materialien lackieren oder kleben? (Z.B., Metall, Plastik)?
A2: Ja, but use compatible products:
- Malerei: Use silicone-specific high-temperature paints (Z.B., silicone-based enamel) that withstand 300°C+—standard paints peel or burn.
- Bindung: Use silicone adhesives (not epoxy or super glue, which don’t adhere to silicone). For metal bonding, choose a high-temperature silicone adhesive with a peel strength of ≥5 N/cm.
Q3: Wie prüfe ich, ob ein Hochtemperatursilikon für Backformen lebensmittelecht ist??
A3: Check for two key certifications:
- FDA 21 CFR 177.2600: Ensures no harmful chemicals leach into food.
- LFGB (EU): For European markets—confirms compliance with food contact regulations.
Always ask the manufacturer for a certificate of compliance; avoid using non-certified silicone (even if labeled “high-temperature”) for food applications.