Nowadays, although the level of technology is very high, the sealing and protection technology of many products in the actual operation process, there are still certain defects, such as cell phone waterproof seals, automotive lamps and lanterns waterproof seals, and seals material selection silicone (a rubber material) is one of our most common, so silicone seals as a class of seals used in many aspects, in the normal use of the process often There will be some unexpected functional problems, so it is difficult to achieve the actual effect, so what are the objective factors affecting it?
(1) Gap problem
The gap problem can be divided into two factors; one is because of the material of the rubber problem, many silicone materials due to the formulation the reason for poor resilience; tensile force is not enough to lead to the use of the process due to the strength of the gap resulting in leakage. Second, the silicone ring manufacturer processing problems, such as products that do brittle lead to the product rolled edge thickness of a thin class prone to this problem, soft lead to the rubber material having an internal bulging package not cooked, long-term stretching after pressure deformation gap problem.
(2) the process of force
shaped silicone rings are generally installed in grooves, planes, and convex grooves. The installation method of each product is different, and its stress process will also affect the service life and function of the product. Therefore, to ensure the sealing performance, it will be placed here. Make a reserved position to distinguish the different usage methods and stress levels of silicone rubber sealing rings. For example, how much force can be loaded on a flat surface depends on the tightness of its deployment and the stress levels of concave and convex types. , the degree of reservation in the selected size.
(3) Compression permanence
Another indicator to assess the O-ring seal’s performance is the deformation of the selected material in compression. Under the action of pressure, as the original elastic O-ring produces elastic deformation, the increase in pressure will also appear as permanent plastic deformation. Silicone seals are subject to stretching or compression when installed in the groove. If the values of stretching and compression are too large, it will lead to an excessive increase or decrease of the O-ring cross-section because stretching by 1% will reduce the cross-sectional diameter by about 0.5%. For hole seals, the O-ring stretches, and the allowable stretching force is 6%. The O-ring is preferably compressed along its circumference for shaft seals, and the allowable circumferential compression is 3%.
