Web cleaners are designed to remove contaminants as small as 1 micron from rolls and webs. They are used in the coating, laminating, printing, and converting industries for the production and processing of paper, film, foil, and fabric. Dirt and other organic particles, when suspended in the air of a pressroom or converting department, pose a problem in that they are often attracted to moving webs. To minimize the potential defects on a printing press or converting line, many web cleaners provide static control and moisture control to minimize this attraction.
Dirt, dust, chaff, loose fibers, additives, powders, and other contaminants can be removed from webs by a variety of methods. Both contact and non-contact systems are available. Vacuum web cleaning systems feature air cylinders that engage and separate rolls. Quick-release gudgeons permit the quick removal of tapes while an anti-static bar is used for particulate removal. When selecting vacuum web cleaners, specifications such as width and number of roll assemblies are important to consider. Typically, the width is measured in inches (in). Vacuum web cleaners with basic 4-roll or 6-roll assemblies can provide both top and bottom web cleaning.
Web cleaners that use vacuuming techniques should apply force evenly across the entire width of the web. Device positioning and configuration are also important components of these web cleaning operations. If the seal between the web and the vacuum is broken, dirt and other particulates may not be removed. Most vacuum web cleaners are designed to remove moderate levels of contamination of around 25 microns. Contact web cleaning devices are well-suited for applications in both the graphic arts and electronics industry. With contact web cleaners, a rubber roller aids in the penetration of the boundary layer of air.
Mechanical methods for web cleaning may include systems with brushes. Such web cleaners are cost-effective, but may risk scratching the surfaces of sensitive or delicate materials. Often, web cleaning systems combine both vacuum capabilities and direct mechanical contact. For example, some web cleaners have static elimination bars that are designed to agitate and free dirt, dust, chaff, and loose fibers. An integral vacuum system then removes these particles and contaminants from the web or roll. In a pressroom environment, such quality assurance (QA) methods are used to minimize blemishes and ensure color accuracy.