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Every roller in a machine line serves a purpose. Therefore, every roller could be classified as a custom roll. C.R.E.W. specializes in custom rolls. We use the specific information that's provided to us to design and build the optimum roll for its purpose. That's why it's important to fill out the Check Sheet for Custom Rolls form as completely as possible.
Air Turns Not technically a roller per se because it doesn't rotate, air turns perform the function of a roller when contact with the web will disrupt a coating or printing on the web. The web floats over the surface of the air turn on a cushion of forced air at a predetermined wrap angle, thereby maneuvering the web into position like a roller. Air turns are also used to flip the web when a pair is used in a turn bay. Anilox Rolls Anilox Rolls and Gravure Rolls apply (depending upon the configuration) ink, adhesive or some other liquid to the web. They are either engraved or coated with a porous surface to contain the liquid until its application. The amount of liquid and its viscosity is needed to determine the amount to be applied. Anvil Rolls See Slitter Rolls. Calendar Rolls Calendar Rolls (usually configured in pairs) are used to gage a web from a heavier thickness to a predetermined thickness by running the web through a controlled gap. Depending upon the type of web to be calendared, the rolls can be heated and/or hardened. In many instances, there will be a number of pairs of calendar rolls in the process before the web is calendared to the proper thickness. Carbon Fiber Idler Rolls Carbon Fiber Idler Rolls, either dead shaft style or live shaft style, are primarily used when both high strength and low weight are required. This is due to their high expense and extended lead time. Coating Rolls Coating Rolls are probably the most precise rolls specified. For example, the quality and uniformity of the coating on the web is primarily determined by:
When you're talking about coatings on such webs as magnetic tape or polarized film, this thickness is measured in microns and is critical to the final product. C.R.E.W. has manufactured Coating Rolls and Bearing Housings for both OEM's and end users to run out and straightness tolerances of 0.00002" (20 millionths of an inch). Our attention to detail, along with dedicated craftsmen and precision machine tools, allow us to produce rolls to your most critical specifications. Dancer Rolls Dancer rolls are usually lightweight dead shaft idler roll whose primary purpose is to sense and smooth out changes in web tension. The important feature of a dancer roll is its total weight. The lighter the weight, the more sensitive the roll will be. Dancer rolls are connected to a transducer which provides feedback to the controls for maintaining correct tension on the web. Drive Rolls See Nip Rolls. Gravure Rolls See Anilox Rolls. Idler Rolls Idler rolls are the backbone of most web fed applications yet they don't get the credit for a quality product. A quality idler roll usually goes unnoticed in the overall operation of most lines. Conversely a poor quality idler gets noticed a lot:
See Nip Rolls. Nip Rolls Some rolls are subject to heavy loading during use: to pull the web; to laminate two webs together; to drive other rolls; etc. Called by a variety of names (drive rolls, layon rolls, laminating rolls, contact rolls, etc.), these rolls have one thing in common - they are nipped against something by mechanical, pneumatic or hydraulic force. In many cases, the nip roll is rubber covered. When you need a nip roll and aren't sure how strong it needs to be, let us know about your application. If you're updating an existing line and need to know if your present rolls will work, we can advise you there, also. Here is a list of points to consider that all go into the equation to design an optimum, safe roll:
Plate Cylinders
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Custom Rolls - www.crewinc.net