At Coast Controls, we understand that each manufacturer has specific needs for their web guiding applications or converting needs, so we offer three types of idler roll materials:
aluminum (6061-T6), steel (A513 DOM), and stainless steel (Grade 304). However, certain applications require a rigid idler that is also lightweight to achieve low rotational inertia for low web tensions. This is most commonly where the aluminum idler comes in. Aluminum idlers can also be hard coat anodized to achieve greater wear resistance especially when the material wraps the idler greater than 90 degrees or the material is abrasive.
Steel idlers can be engineered for a wide range of applications. However, Steel idlers are often used with higher web tensions, wrap angles greater than 90 degrees and elevated temperatures up to 350Ëš F. Steel idlers also have a higher resistance from surface blemishes and deflection.
Stainless steel idlers are great for corrosive and high moisture environments. Each roller is designed to meet the exact specifications of its intended use. These idlers provide exceptional performance over a wide range of applications while possessing a higher wear resistance than mild steel. Typical applications include food and medical environments. Stainless Steel bearings are also available for dead shafts.
Aluminum vs. Steel Idlers:
The most basic difference between aluminum and steel idlers are their weight difference. Aluminum can weigh as much as one-third of a comparable steel idler for the same application, and this is without sacrificing the performance that many have come to trust with steel idlers. In fact, aluminum idlers have a higher corrosion resistance than steel and can still withstand the workload of medium to heavy loading. Another key benefit of aluminum idlers is their lower rolling inertia. Aluminum idlers have 40 - 60% lower rolling inertia compared to comparable steel idlers. These traits make them ideal for low web tension and high speed operations.
Live Shaft vs. Dead Shaft Aluminum Idlers:
If you have decided to go with an aluminum idler, another decision you will need to make is if you want live shaft or dead shaft. Each has their key advantages and the decision depends solely on your unique manufacturing requirements.
Dead shaft aluminum idlers are less expensive than live shaft idlers, which has made them more popular over the years. Also, since the roll body is the only rotating object on a dead shaft idler, the rolling inertia is much less than a live shaft. Dead shaft idlers also benefit by having low friction bearings, which help increase the bearing life span.
The most popular reason people go with live shaft idlers is because they can work in harsher environments like those that involve damaging chemicals or vapors, high levels of dust, or excessive moisture. Also, since the bearing size is not limited to the size of the idler roll body, live shaft idlers can withstand higher workloads. Another key advantage of live shaft rollers is that they can allow for longer rolls since self-aligning bearings can be used. Live shaft idlers can also work in elevated temperatures when positioning the bearings outside the harsh environment which prolongs the bearing life.
Coast Controls engineers the equipment you need, and we can customize our idlers to work best for you. We also have manufactured superior web guiding equipment for over two decades so you can be rest assured that you are receiving a quality product that won’t break down.
About the Author:
Kyle Koontz, of Coast Controls Inc. in Sarasota, Florida, is a veteran of the converting industry. Mr. Koontz began his career with Coast Controls in 2006 and worked his way through the ranks to his current position as Vice President of Manufacturing. A graduate of Rhodes State University, he also enjoys boating, fishing and fitness in his spare time.