Dave’s Favorite Defects: Tin Canning
By Dr. David R. Roisum
The tin can is a quite common, yet quite commonly misunderstood, film-winding defect. We will begin by saying what a tin can is NOT. It is not a series of moisture welts. It also is not a series of gage bands, such as due to streaks in manufacturing, coating or printing. It is not a corrugation, which is a totally different defect.
What a tin can is, is a tight defect that is the result of winding physics that are common to every wound roll ever made, but tends to manifest itself as a defect only on certain grades of thin film.