Why store spools in two positions? Why pause production when changing the parent roll? Why not have a winder with two unwind stands instead? Valmet’s Dual Unwind is an exceptionally fast way to make a parent roll change at the winder. You’ll end up with more production and higher winder capacity. Valmet has a proven technology with a solid 10-year track record with nearly 40 references!
A decade ago, Valmet launched a revolutionary winding equipment that would significantly increase capacity. The first one was delivered to Propapier. After this first start-up, over 30 Dual Unwind solutions have been sold already to increase winding capacity. Dual Unwinding makes it possible to get rid of additional reel spool storages at the winder. There is no need to pause the production due to parent roll change as earlier. The Dual Unwind sequence is fully optimized and independent of a crane.
Old type of finishing area
New type of finishing area with Dual Unwind
With Dual Unwind, you’ll get:
With conventional parent roll change solutions, fast manual changes are 5-6 minutes. However, typical measured parent roll change times in the industry are on average some 9-12 minutes. With this in mind, a one-minute parent roll change with Dual Unwind is very fast. This alone leads to big savings with the capacity increase at the winder. Depending on the winder, the capacity gain can be substantial.
The movements of parent rolls are arranged to happen simultaneously with the set changes, which is a robust solution to ensure there are no compromises to the roll structure and quality during winding. The second unwind stand is designed only for unwinding the last set from the parent roll. This allows the primary unwind stand to receive a new, prepared parent roll during winding.
The dual unwind can be delivered with two different splicing technologies, a conventional flying splice or a butt-joint splice, BJS, which will prepare a sellable splice.