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What Causes Rubber Expansion Joint Bulge?

2017/2/9 17:16:44      Click£º

Some flexible rubber joints may has bulge in service, why? Based on our rich experience on flexible rubber joints manufacturing, we find that the main cause of flexible rubber joint bulge is that the tyre fabric in inner rubber layer doesn¡¯t closely fit with the rubber, and this lead to gap between tyre fabric and skin layer rubber. So when conduct bulge test for the flexible rubber joints, when water flow into the gap, while skin rubber content is high, in this condition, there would has bulge on flexible rubber joints surface. Do you know why?

Inner rubber layer contains a large a mount of waste recycled rubber.

Use recycled rubber helps to greatly shrink the cost, since the inner rubber layer of flexible rubber joints is hard to be observed, thus, many semiworks make jerry-build on it, and this lead to poor leakproofness of the inner rubber layer, and water permeate to tyre fabrics.


Poor cord fabric quality.

Because cord fabric of the flexible rubber joints is hidden in the rubber, so some semiworks produce poor quality cord fabrics to lower the cost, so that cord fabric doesn¡¯t play the function of sealing, water still permeate to cord fabric layer and generate bulges.

High content skin rubber layer.

Some cunning semiworks manufacturer produce flexible rubber joint skin layer in high rubber content. The reason is simple, skin rubber layer can be seen by customers directly, they think customer may identify flexible rubber joints quality directly through the appearance. Some customers may pull the rubber fur on surface, if tensile force is large, they may think the quality is excellent. Poor inner rubber layer with high rubber content skin rubber layer, water won¡¯t pull out since skin rubber layer is so hard, and poor cord fabric layer can not bear the pressure, at this time, bulge appears.