Research on Unwind and Splicing Based on Polynomial Interpolation

Aiming at the problem that the initial roll diameter of the new web axis and the unwind speed after splicing cannot be determined due to the change of web diameter when the axis of the unwind unit of the flexographic press is switched. In this paper, firstly, the web diameter corresponding to the rotation angle of the cantilever is obtained by the simulation ofCADon the basis of keeping the angle of the splicing web and the cutter unchanged. Secondly, a polynomial interpolation algorithm for the rotation angle and web diameter of the cantilever is proposed. Newton interpolation polynomial algorithms are used respectively to analyze the functions obtained by different polynomial degrees, and the optimal approximate curve is obtained. Finally, the experimental verification is carried out on the production site. The simulation and experimental results show that the proposed algorithm can obtain the accurate value of the initial web diameter only according to the rotation angle of the cantilever when the new axis is predriven. The new method replaces the ultrasonic sensor detection unit, solves the problem of determining the unwind speed of the unwind cantilever, and avoids the tedious process of making the test mould. It reduces the waste of the material film, saves the debugging cost, optimizes the unwind process, realizes the functions of calculating the initial diameter and the pre-driven speed of the unwind.