Tutorial on Winding Polyolefin and other Flexible Films

摘要

Every polyethylene, polypropylene and/or other flexible film producer is faced with the challenge of consistently producing quality rolls of film products. This paper is a tutorial on film winding. It addresses the definition of a quality roll of film and the importance of inwound tension in consistently producing good quality rolls. It then discusses the winding principles used on all winders to control inwound tension or roll hardness. It explains how to determine the proper amount of web tension for various types of films and the principles of nip and gap winding. Then the basic types of center, surface and combination center/surface winders will be compared with the advantages and disadvantages of each. After the discussion of how roll hardness is achieved, methods of measuring roll hardness are presented. Finally, other roll defects to avoid in producing quality rolls of film will be listed and the book "Roll and Web Defect Terminology" will be brought to the audience's attention for them to learn more about the causes and cures of common roll and web defects.