When a pneumatic fiber transfer system required a large bell in a short space, we had to get creative. The system was in need of a bell that would transfer the fibers at high speed from a 3-5/8″ ID up to a 5 1/2 ID in about 12″ in length. That type of bell not only should expand the ID, but it should gently guide the fibers as they blast through it. The smaller tube with a 0.187 wall would thin to a 0.115 wall, but as the bell side is clamped to the larger sized tube, so a thin wall is not an issue. What was the issue is: 1) the fiber moves rapidly 2) the transition must be smooth so as to protect the product, and 3) we had only 12″ to make the transformation bell.
We needed to develop a new technique, but were happy to take the challenge, and were pleased with the results.