Festoon-style vertical accumulator for continuous process lines allows for core changes and product splicing while enabling the process line to continue at a constant velocity. The SplicePerfect can accumulate material at high speeds even when the down-line process has been stopped. This allows the upstream process to continue uninterrupted. Once the down-line process resumes, the accumulator system will feed out at speeds in excess of the process line speed. The company’s unwind, rewind and cantilevered systems for continuous webs are compatible.