Silicone sealant performance characteristics and term explanation

Silicone sealant, except for strong alkali and hydrofluoric acid, does not react with any substance, does not dissolve in water and any solvent, non-toxic and odorless, stable chemical properties and other performance characteristics, the following small series will introduce to you the explanation of related terms .

1. Appearance: The appearance is the surface shape of the sealant, mainly to observe the color, shape and presence or absence of foreign objects, gel particles, air bubbles, whether the sealant is uniform, etc. (Note: The state of the sealant is generally divided into Paste, paste fluid, semi-flowing, and flowing).

2. Thixotropy (sag resistance): Thixotropy is the property that when the colloid is sheared, the consistency becomes smaller, and when the shearing stops, the consistency increases again. It is an important process performance required for the rubber material to be constructed on the vertical facade.

3. Surface drying time (min): The surface drying time is to squeeze the adhesive onto the glass plate or other flat materials, and gently touch the surface of the glue with the surface of the finger or toothpick until the surface of the finger or toothpick is not sticky. The time from the extrusion of the sealant to the non-adhesive is called the surface-drying time of the sealant.

4. Viscosity (mpa, s): Viscosity refers to the measurement of the internal friction between molecules when the liquid is moved by external forces. It is an index to evaluate the fluidity of liquid silicone rubber. The viscosity decreases with the increase of temperature.

5. Density (g / cm3): Density refers to the mass of the substance contained in a unit volume at a specified temperature.

6. Shore hardness (A): Shore hardness is a physical measure of the degree of deformation or puncture resistance of a substance under compression.

7. Tensile strength (MPa): That is, the tensile force withdrawn per unit area of ​​silicone rubber. If the tensile strength is large, the corresponding product has high mechanical strength, which is an important indicator for measuring rubber.

8. Shear strength (MPa): Shear strength is the maximum breaking load per unit area when the sealant bonded test piece is subjected to stress in the shearing direction.

9. Thermal conductivity (W / (m · k)): Thermal conductivity refers to a material with a thickness of 1m under stable heat transfer conditions. The temperature difference between the two surfaces is 1 degree (K, ° C), within 1 hour Heat transferred through an area of ​​1 square meter.