High Tear Strength Liquid Silicone Rubber For Durable Casting And Demolding Cycles
Description of Tin Cure Silicone Rubber
HN-620 consists of two components, A and B. To ensure that the physical properties of the material reach their optimal level after curing, it is essential to strictly adhere to a mixing ratio of 100:2 by weight during operation (i.e., 100 grams of Component A to 2 grams of Component B). It is recommended to use an electronic scale for precise measurement during the mixing process and to stir thoroughly until the mixture achieves a uniform color, thereby preventing issues such as localized incomplete curing or inconsistent hardness caused by inadequate mixing.
Application of Tin Cure Silicone Rubber
Architectural Decoration: Mold fabrication for large-scale stonework, gypsum components, cement elements, cultured stone, Roman columns, and carved stone furniture.
Arts & Crafts: Sculptures of lifelike animals and plants, resin crafts, Poly-resin ornaments, carved Buddhist figures, and various gypsum decorative items.
Technical parameter of Tin Cure Silicone Rubber
| Model |
HN-620AB |
| Feature |
low viscosity |
| Viscosity (cs) |
170000 |
| Gravity ( G/cm 3 ) |
1.06 |
| Hardness(A°) |
20 |
| Strength( MPa) |
3.1-3.6 |
| Tear Strength (kN/m ) |
19.8-24.3 |
| Elongation(%) |
600-720 |
| Linear Shrinkage(%) |
≤0.2 |
| Curing Agent Addition Ratio(%) |
2-3% |
| Operating Time( mins ) |
30-40 |
| Curing Time( hours ) |
3-4 |
Feature of Tin Cure Silicone Rubber
1. Two-Component System: Flexible Mixing Ratio, Stable Curing. HN-620 A/B utilizes the classic AB two-component RTV-2 (Room Temperature Vulcanization) system.
- Component Composition: Component A consists of a high-performance liquid silicone rubber base, while Component B serves as a specialized curing agent.
- Convenient Operation: Typically mixed at a ratio of 100:2, users can flexibly control the working time and curing speed by slightly adjusting the amount of curing agent used, depending on the ambient temperature and humidity.
- Room-Temperature Curing: The material achieves full curing at ambient temperature without the need for heating equipment, thereby significantly reducing energy consumption and equipment costs associated with mold making.
2. Exceptional Physical Properties: Superior Flow and Hassle-Free Casting—An Optimized Solution Designed for Large and Complex Molds:
- Excellent Fluidity: The liquid silicone exhibits a flow-like spreading capability, rapidly penetrating and encapsulating every minute detail on the model's surface to ensure that the resulting mold reproduction features crisp, distinct textures.
- Self-Degassing Performance: Its outstanding de-aeration capability allows bubbles generated during mixing to quickly rise and dissipate; even without the use of vacuum equipment, its inherently low viscosity ensures effective, ideal bubble elimination.
- Ease of Application:Whether utilizing brush-on or pour-on molding techniques, the material facilitates effortless, large-scale casting, thereby significantly boosting production efficiency.
3. Industrial-Grade Durability: Featuring robust weather resistance and dimensional stability, this material offers physical and chemical defenses specifically engineered for demanding production environments:
- High/Low Temperature Resistance: Once cured, the mold exhibits exceptional thermal stability, capable of withstanding prolonged exposure to high-temperature casting processes without becoming brittle.
- Acid and Alkali Resistance: Designed to withstand highly alkaline or acidic production materials—such as cement, gypsum, and artificial stone—the silicone's stable molecular structure resists chemical degradation, corrosion, and swelling.
- Ultra-Low Shrinkage Rate: Boasting an extremely low linear shrinkage rate, it ensures dimensional consistency for large-scale architectural components (such as Roman columns and monumental sculptures) across multiple reproductions, thereby preventing mold distortion.
MethodofApplication:
1. Mixing Ratio and Procedure: Before use, please shake Component B (the curing agent) thoroughly. Weigh the components strictly according to a weight ratio of A:B = 100:2. During mixing, pay particular attention to scraping the bottom and side walls of the container to ensure the silicone and curing agent are thoroughly blended. Note: Incomplete mixing will directly result in localized uncured areas within the mold, significantly reducing the mold's service life.
2. Vacuum Degassing:Place the thoroughly mixed silicone mixture into a vacuum chamber to remove air bubbles. The vacuum treatment duration should not be excessive; it is generally recommended to limit the process to within 10 minutes to prevent over-vacuuming from compromising the material's performance.
3. Curing and Maturation: This product utilizes a room-temperature curing system; the mold will fully cure within 4 hours at ambient temperature. Direct high-temperature heating to accelerate curing is strictly prohibited; if accelerated curing is required, the ambient temperature should not exceed 100°C. To achieve optimal physical properties, it is strongly recommended to allow the mold to rest for 24 hours after curing before putting it into production for casting.

