There is a way to cut chilled-iron roll grinding costs

You know as well as anyone about the need to examine all grinding costs to see if something can be done. You also know it is not easy to find savings that add up to an important amount. Most of the good ideas require investment and that can be a problem, especially now. What you could use is a solid idea that costs little but saves a lot. If it improves roll quality and is easier on the operator, that is a bonus. We have an idea for you.

Your grinding method may be costing more than you realize

You may be using shellac wheels and feel they work as well as can be expected. Actually, they could be costing you plenty due to moderate removal rates, chatter, and wheel changes. You may be using abrasive belts and feel they are easier than wheels. They could be costing you plenty. Belts do not last long and are expensive. They could cost hundreds of dollars per roll plus have some finishing problems. You may be using a superfinisher and feel it is the best way to finish. It is slow, however, and cannot easily remove chatter or deep grit marks. It needs time to set up for each roll.

This is where Pacer can help

That was the bad news. This is the good. You now can simplify and save plenty. What you need is one wheel to do the entire job. You need Pacer’s new C100I11PM2. You could look at it this way: If a mill were successful using one wheel that roughed fast and finished great, would it then decide to increase downtime by changing wheels from roughing to finishing and then back again every roll? Would it decide to greatly increase abrasive costs by switching to belts? Would it decide to increase semi-finishing and finishing time by switching to a superfinisher? The answer to all three is, not very likely. 

The main reason mills decided in the past to spend time and money on those methods was because one wheel could not rough fast and finish great - without chattering. Now one can. Now you can eliminate unproductive time and excess abrasive costs. Other mills are saving. You can too. Check out the enclosed information and then call us.

Having problems with stainless or hard-covered rolls? Then you can save even more.

You Want to Reduce the Cost of Roll Grinding.
(and improve surface quality)
This Is the Way to Do It!

The three approaches to reducing the cost of grinding chilled-iron rolls:

1. Reduce grinding time (roughing and semi-finishing and finishing)
2. Eliminate wheel changing time (after roughing and after finishing)
3. Reduce abrasive cost (wheels, belts or hones)

The way to do all three is to grind faster with one wheel that wears slowly

Simply put, you need a finishing wheel that can hog. Paper mills always have wanted a good roughing/finishing wheel and why not? It would rough and then just ease into finishing. No changing wheels after each phase. No adjusting speeds and feeds often to avoid chatter. No dealing with the time and other problems of belts or a superfinisher. Much better for the operator. Excellent profile and surface. This user-friendly wheel would simplify grinding and save a lot. It would do it all. 

The problem, however, is that no wheel has been good enough to do the entire job well. Some mills use a shellac finishing wheel to rough but the removal rate is low. Some use a roughing wheel to finish but have deep grit marks. Many mills change wheels (four changes for a two-wheel machine) but that takes time and can be physically demanding. Mills finishing with belts or a superfinisher can have stubborn leadlines, grit marks or waves. Many operators feel the quality of a wheel finish is best.

NEWS FLASH - Pacer has designed one wheel that does it all

Pacer has made roll grinding wheels for over 250 North American and overseas paper mills. These are the popular PM roughing and Cork finishing wheels. They rough or finish great but generally are not intended to do both. Paper mills need a wheel that does both. There would be many advantages and cost savings. Pacer now has the special wheel you need. It is the C100I11PM2.

Because this 100-grit wheel roughs and finishes, no time or effort is wasted changing wheels or going to belts. Various 100-grit shellac wheels have been around for years. This is not a shellac wheel. It is new and different. It grinds fast, finishes great and lasts long. Some mills have switched to belts or superfinishers because of chatter or other ongoing wheel problems. Many have found, however, that the switch has not been totally successful. Those methods have their own cost and quality problems, some serious. If one grinding wheel can rough and finish well, that is the way to go. It is more natural grinding. There would be little need to bother with add-on machinery and abrasives.

This is a 100 grit wheel that thinks it is a 60 (or even 46) grit wheel

It thinks so because it cuts so well. The grit is smaller but there are many, many more of them. A good 100-grit wheel should be aggressive and smooth. Easy to say but not easy to design. The grit has to adhere extra well. The structure has to be extra open for resilience. The bond has to be extra tough. The C100I11PM2 has all these extra features. Our grit coating process is new and very adhesive. Our 11 structure is new and very open. Our patented PM resin bond has high strength but “give”. That and the open structure stops chatter. This is one easy, 2 to 4” wide, cost saving wheel.

The C100I11PM2 roughs fast because it is sharp and aggressive. It semi-finishes fast because of the already good surface after roughing. It finishes fast because of no chatter. Long life means rock-bottom abrasive cost, especially compared to belts. You can expect a 4 to 6 Ra and a bright, reflective roll. Operators can expect not to change wheels. This wheel does it all. We guarantee it. 

Also, you should see how it handles the always difficult 
stainless-suction and hard-covered rolls.

Now is a good time to rethink grinding methods

The job may seem to get done ok now. Your present method likely is the result of many past efforts and may seem to be as good as it gets. Another method, however, might be better - a lot better. It could generate significant savings, higher quality and be easier on the operator. That is worth taking some time to compare your method to this one. Such savings and improvements are not easy to find.

Comparing the present (old) method to the new method

The best way to consider cost savings is to compare the cu” per hr chilled-iron removal rate, wheel changing time, etc. to see how the methods match up. Following are grinding steps and an example:

1. Roughing – You should be removing from 15 to 25 cu” of iron per hour. An easy way to calculate removal rate is (3.14 x roll diameter x diameter removed/2 x roll face) / hours. Measure the roll before and after a 2 to 4-hour period. The C100I11PM2 does at least 15 cu”/ hour. That is efficient for removing up to about .015”. For heavier removal, Pacer’s green 60 or 46-grit wheel does 20 to 25 (or even 30) cu”. A 100-grit or cork wheel would be used next.
2. Semi-finishing – You should be making only about 4 to 8 passes to remove grit marks and improve profile. Once roughing is done, note the time spent on lower amp passes to prepare for finishing. Coarse wheels usually need more passes because their grit marks are deeper and the profile often varies more. The fine cutting C100I11PM2 should reduce this phase by half.
3. Change to finishing wheel – About ˝ hour for one wheel. None with the 100-grit.
4. Finishing – You should be making only about 12 to 18 passes to remove spiral lines, get profile and improve the finish. Finishing is when shellac wheels can be difficult and lose a lot of time. If chatter occurs, time is spent removing it and then starting to finish over again. The C100I11PM2 is steady at 0 to 30 working amps and generates an impressive roll appearance.
5. Change to roughing wheel – About ˝ hour for one wheel. None with the 100-grit.

Example - Assume a present roughing rate of 12 cu”/hr and a total needed removal of 100 cu” and a two-wheel Farrel and a change of wheels. The comparison to Pacer’s C100I11PM2 would be:

1. Roughing 8 hours vs. 6.5 for Pacer save 1.5 hours
2. Semi-finishing  2 1.0 1.0
3. Change wheels 1 (2 x ˝)   0 1.0
4. Finishing 6 4.5 1.5
5. Change wheels 1 (2 x ˝)   0 1.0

Totals 18 hours vs. 12 for Pacer save 6 hours

The results show a 33% time saving. Multiply that by the rolls per year, and you will see a big number - too big to ignore. There also is the 33% abrasive saving to consider. The C100I11PM2 has longer than normal life. Its infeed rate can be set 1/3 lower than for shellac but still remove the same material; thus, two would last as long as three shellac wheels. The abrasives cost per roll for belts is much higher than for this wheel (which is about $70 per big roll). Worn-out belt cost could be several hundred dollars per roll – plus more time and less quality. You now have a better way to do the job.

Call, fax or e-mail now to order a guaranteed trial wheel — and start saving soon!
610-383-4200      Fax: 610-383-4239 
200 Red Road, Coatesville, PA 19320


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