What are the Main Characteristics of Epoxy Resin Glue Before Curing?
The main characteristics of epoxy resin before curing are color, viscosity, specific gravity, proportion, gel time, time to use, curing time, thixotropy, hardness and surface tension.
Viscosity: it refers to the internal friction resistance produced by the colloid in the flow, and its value is determined by the type, temperature, and concentration of the substance.
Gelation time: the curing of glue is the process of transformation from liquid to curing. Starting from glue, the critical time of colloid to solid is gel time, which is determined by the mixing quantity and temperature of epoxy resin.
Thixotropy: this property refers to the phenomenon that colloid is thickened and diluted with external force when it is touched by external force (shaking, stirring, vibration, ultrasonic, etc.). When the external factors stop acting, the colloid returns to its original consistency.
Hardness: it refers to the resistance of the material to the external force such as imprint, scratch and so on. According to the test methods, there are different hardness of Shaoshi (Shaw), Brinell hardness, Rockwell hardness, Mohs hardness, Pasteurella (Barcol) hardness, Vivtorinox (Vichers) hardness and so on. The hardness value is related to the hardness type. In the commonly used hardness tester, the Shaw hardness tester is simple in structure and suitable for production inspection. The Shaw hardness tester can be divided into A, C and D type. A is used to measure soft colloid, C and D are used to measure semi hard and hard colloid.
Surface tension: the attraction of the molecules inside the surface causes the molecules on the surface to operate under an internal force. This force reduces the surface area of the liquid and forms the force parallel to the surface, which is called surface tension. Or it is the mutual traction force in the unit length between the two adjacent parts of the liquid surface, which is a manifestation of the molecular force. The surface tension of the unit is N/ ㎡. The size of the surface tension is related to the properties, purity and temperature of the liquid.