The quality of mold silicone directly affects the operation and performance of the mold. Viscosity, hardness, tear resistance, and tensile strength are all decisive factors in its quality. How to judge the quality of mold silicone?
1. Silicone Viscosity: The fluidity of silicone is determined by its viscosity. During testing, shovel liquid mold silicone into a container and let it flow naturally. The faster it flows, the better the fluidity. However, it's important to note that
viscosity and tear strength are directly proportional. Do not use excessively low viscosity silicone to pursue better fluidity, as this will result in poorer tear resistance and fewer mold repeats. Some manufacturers add excessive silicone oil to increase the fluidity of the mold silicone, which can also lead to poor tensile strength.
2. Silicone Hardness: The hardness of silicone is an important technical indicator reflecting the rigidity of the silicone material. When the hardness of mold silicone is below 10 degrees, the silicone has low tear strength and high elongation, making silicone products prone to deformation.
When the hardness is above 50 degrees, the tear strength deteriorates, and silicone products become brittle and easily break or fracture. Generally, a silicone hardness of 20-40 results in optimal tear strength, elongation, etc.
3. Tear Strength: Silicone products with high tear strength exhibit outstanding resistance to damage, have a long lifespan, and are less susceptible to external environmental interference. Silicone products with poor tear strength are generally prone to tearing during the tearing process, and the tears rapidly expand under stress, leading to failure.
4. Tensile Strength: The tensile strength of silicone materials affects the molding process. Silicone materials with poor tensile strength produce silicone with poor toughness and insufficient tear strength, making it difficult to remove edges during molding.
