I was raised in a Southern Indiana dairy farm area and had worked the farm since I could walk. From throwing hay bales, weighing some 50 pounds, and cleaning out stalls, I have done jobs that would make Mike Rowe—the host of cable television’s Dirty Jobs—cringe.
When I was given the opportunity to begin a career, I jumped at the chance. I started off in printing at Southern Gravure in Louisville, KY, on third shift, at what they called the “worst job” they had. Of course, they didn’t realize their “worst job” was nothing compared to the jobs I was doing on the dairy farm.
On top of that, Southern Gravure was paying three to four times the hourly rate I was getting on the farm. I spent the first part of my career scared that I was not doing enough to get that kind of compensation. I still remember the day they asked me to come in on day shift for a meeting with the boss. I thought they had finally realized their error and were going to let me go.
Instead, they offered me an apprenticeship. I was stunned! Only after asking them to repeat what they had just said—twice—did I accept. I started my apprenticeship on a manual lathe. This is where I first heard of the term TIR.
Fast forward 34 years to today, this former Southern Indiana farm boy has been asked to explain how TIR affects anilox roller performance.
What Is TIR?
Let’s start out and define what TIR means: TIR is an acronym for Total Indicator Reading or Total Indicator Runout. FIM, or Full Indicator Movement, has also been brought into the common nomenclature and has the same meaning as Total Indicator Reading. These two terms take into consideration flat pieces as well as round and tapered parts. They measure the surface finish and contour of the part, as well as concentricity. We will reference these terms later in this article.
All photos courtesy of Interflex Laser Engravers
Total Indicator Runout, on the other hand, is traditionally used for cylindrical parts only. With Total Indicator Runout, a dial indicator is used to measure the amount of movement on a rotating part, based on its referenced axis points. In layman’s terms, it wobbles when it spins on its axis. This wobble is called “run-out.” This is the translation of TIR that I will be using to discuss the first part of this article.
Good TIR Tolerance
When processing and measuring anilox rollers, it is important to follow the tolerances listed on the specific press manufacturer’s prints. This is normally between 0.001-in. and 0.0005-in. The internal tolerance we achieve at Interflex Laser Engravers is 0.0002-in.
Here is an example of how tight of a tolerance that is: A piece of printer paper has a thickness of about 0.001-in. If you could take that thickness and divide it into 10 pieces of identically thick parts, and then get rid of eight of them, that is the amount of movement we would allow on a rotating anilox.
How does one determine which axis point to use for the TIR measurement on shafted anilox rolls? Some manufacturers will process and measure based on the center of the roll. When we asked our customers how many presses run off the centers, the answer is none. Understanding this, we measure all of our TIR readings from the bearing surface instead, because this is the way you are running in your presses. If the face of the roller and all of its shafts are running true to the bearing surface, you will not have issues with run-out.
Sleeves and non-shafted tube-type cylinders are a little different, as they don’t have an axis point to reference (no shaft). Their concentricity is based on their outer and inner surfaces running together. The true test of run-out is when the sleeve is pressed onto your press mandrel. At this point, you can properly measure the amount of run-out that you have.
To help reduce the chance of issues occurring when you check the sleeve on your press mandrel, Interflex Laser Engravers places each sleeve on a mandrel, similar to what you have in the press, and processes it based on the bearing surfaces. We invest in these mandrels to ensure we create the same environment that you encounter in your process. This greatly enhances the success of your sleeve performing as it was designed.