Anilox Rolls

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

Anvil Rolls
See Slitter Rolls.

Calendar 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
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
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:

• the amount of runout measured from the bearing journals to the roll body
• the straightness of the roll body
• the cylindricity of the roll body
• the surface finish of the roll body

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. CREW has manufactured Coating Rolls and Bearing Housings for both OEM's and end users to run out and straightness tolerances of .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
Dancer rolls are usually lightweight dead shaft idler roll whose primary purpose is to sense smooth our 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

Drive Rolls
See Nip Rolls.

Idler 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:

• If it's out of balance, it can cause undo vibrations throughout the machine line.
• If its straightness isn't held, it can cause web drift.
• Rough surface finishes or surface defects might mark the web.
• Excess runout shows up as angular misalignment and can cause a myriad of problems.

At C.R.E.W., we're intimately familiar with idler roll standards of the industry and we not only meet them, but beat them. As a general rule, you can expect a C.R.E.W. idler to meet the following criteria:

• 32 Ra surface finish
• Dynamically balanced to well within Quality Grade G 6.3 @ 1000–2000 FPM (or your line speed)
• Straightness across the roll face within .0005 per foot of face length
• Runout within .002–.005 (depending upon the diameter-to-face ratio)
• Materials: steel, aluminum, stainless steel & carbon fiber

Laminating Rolls

Laminating Rolls
See Nip Rolls.

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.
Things such as:

• cylinder size
• air or fluid pressure
• any mechanical advantage
• bearing centerlines
• speed
  all go into the equation to design the optimum, safe roll without any overkill

Plate Cylinders

Plate Cylinders
Plate Rolls, or Plate Cylinders, have a polymer plate attached to them for printing the web. The plate is either mounted on a sleeve that is air loaded onto the mandrel/plate roll, or attached with stickyback. Plate cylinders need to have precise concentricity for quality printing. C.R.E.W. has made hundreds of these cylinders having concentricity within .0002-.0005.

Slitter Rolls

Slitter Rolls
Slitter rolls and anvil rolls are hardened rolls (usually over 60 Rc) on which a circular cutter rides in order to part, slit or perforate the web. Some slitter rolls are multi-grooved over which a razor or razors are mounted to slit the web.

Spreader Rolls

Spreader Rolls
Wrinkling has been a problem ever since man started running webs over rollers. Spreader rolls (rollers that are supposed to remove and/or prevent web wrinkling) can take many forms: Herringbone pattern, Chevron Groove pattern, Reverse Taper configuration, Grooved Rubber Cover, to name a few. Different types of spreader configurations work differently depending upon the process, the web material, the wrap angle, etc. The intent is to move the web to the outboard edges and tighten the center of the web, thereby removing or preventing any web wrinkling.