The main parameters of liquid injection silicone include the following aspects:
1. Physical state and appearance
Physical state: liquid, usually in the form of two-component (component A, component B) packaging.
Appearance: Components A and B are transparent and free of impurities. After mixing, they may appear translucent or in a specific color (adjusted according to customer needs).
2. Viscosity and fluidity
Viscosity: The viscosity of components A and B before mixing is usually high, and the viscosity after mixing will also be maintained at a certain level to ensure that the liquid silicone can flow stably and fill the mold during the injection process. The specific value of viscosity will vary depending on the product model and customer needs.
Fluidity: Liquid silicone has good fluidity and can easily enter the fine parts of the mold to ensure the integrity and precision of the product.
3. Mixing ratio and operation time
Mixing ratio: Components A and B are usually mixed in a ratio of 1:1 to ensure the best performance of the product.
Operation time: The mixed liquid silicone has a certain operability time, which can usually be kept at room temperature for more than 1 hour. The specific time depends on the product model and vulcanization conditions.
4. Vulcanization conditions and hardness
Vulcanization conditions: The vulcanization temperature of liquid silicone is usually in the range of 80℃-170℃, and the most suitable vulcanization temperature may be between 139℃-170℃. The vulcanization time varies according to the thickness and shape of the product, generally between a few minutes and more than ten minutes.
Hardness: The hardness of liquid silicone can be controlled by adjusting the formula and vulcanization conditions, usually between 20 and 70 degrees Shore A hardness.
5. Mechanical properties
Tensile strength: Liquid silicone has high tensile strength and can withstand a certain external force without breaking.
Tear strength: Tear strength is also one of the important mechanical properties of liquid silicone, which determines the resistance of the product when subjected to tearing force.
6. Thermal stability and weather resistance
Thermal stability: Liquid silicone has excellent thermal stability and can maintain stable performance at high temperatures without yellowing or aging.
Weather resistance: Liquid silicone also has good weather resistance, can resist the erosion of environmental factors such as ultraviolet rays and ozone, and maintain the long-term performance of the product.
7. Other parameters
Density: The density of liquid silicone is usually between 1.0~1.2g/cm³, and the specific value depends on the product model and formula.
Linear shrinkage: Liquid silicone will shrink to a certain extent during the vulcanization process, and the linear shrinkage is usually around 2%.
In summary, the main parameters of liquid injection silicone include physical state and appearance, viscosity and fluidity, mixing ratio and operation time, vulcanization conditions and hardness, mechanical properties, thermal stability and weather resistance, and other parameters such as density and linear shrinkage. These parameters jointly determine the performance and application range of liquid injection silicone.