Maker of Sensitive Flexible Material Alleviates Tension & Bounce Issues with Double E SRS-2000
Double E had the pleasure of working with maker of holographic flexible material used for packaging DVDs and other products. The customer was using a square journal shafts and safety chucks from a lesser supplier. The square engagement had a loose tolerance fit that allowed the shaft to drop slightly every quarter turn of rotation. While the rotational tapping was irritating, the real problem was the uneven tension and bouncing that often caused wrinkling in the web. A wrinkle early in the rewind process resulted in significant portions of a roll being wasted. Sometimes, the whole roll was unusable. The company's difficulties were compounded by the maker of the shafts and chuck's poor customer service.
Double E's solution to the customer's web tension and bouncing problems began with the Safety Chuck with circular jaw inserts. The safety chuck's circular, spline design minimized the roll bounce, vibration noises, and uneven web tension. Because the spline design is proprietary, Double E also supplied SR-2000 strip shafts.
As it turned out, the bouncing problem was being caused not only by the safety chucks but also by shaft tolerance and strip compression. Double E offered the customer one trial SR-2000 shaft with the new safety chucks. The customer uses a lay-on roller directly on top of the rewind roll. This roller's movement made it possible to see the web bouncing during rewind. The trial run with the SR-2000 focused Double E's efforts toward eliminating the clearance between the OD of the shaft and the ID of the core.
To solve the remaining problem, Double E applied the SRS-2000 self-centering strip shaft. This shaft is machined to a custom OD rather than extruded like the SR-2000. The shaft also combines gripping strips with plastic centering strips. This design minimizes roll bounce due to bladder compression. The SRS-2000 shaft corrected the tension and bouncing issues on the web. In addition, the customer was pleased with Double E's customer service performance and readiness to work with them.
The customer purchased 15 SRS-2000 strip shafts and 7 sets of SM-100 safety chucks. This combination of products works for many flexographic and plastic applications. It is crucial to pay attention to the ID of the core. The SRS-2000 is custom machined and can fit the customer's core more precisely.
