Chipout Problems when Cutting Melamine
Badly sharpened blades, an out-of-tune beam saw, or maybe just too many sheets at once might be causing excess chipout on melamine cuts. July 6, 2006
Question
We have a beam saw and cut three to four units of 2 sided melamine per day. Our main saw blade is 400 mm and has to be changed ever other day. Some days we don’t make it all day without getting chipping and needing to change. I have noticed that sometimes a brand new blade does not cut as well until it has been sharpened. That does not make sense because the cost is very high for these blades. Sometimes we get a zipper cut. The bottom of the panel, which is cut by the scoring blade, looks great, but the top looks rough. Sometimes it does look like a zigzag if you look closely at the cut line. Has anyone else had these problems and does anyone have suggestions on the best blades for a beam saw cutting up to 4 or 5 sheets of melamine at a time?
Forum Responses
(Cabinetmaking Forum)
From contributor A:
There could be a lot of reasons for what's happening. The cut pattern you described is usually brought on by a heated blade. When heated during cutting it will create a slight warp in the blade causing some odd track marks. Usually reduce the number of panels to two or three and watch for the chatter marks. If they are not present then it is a heated blade. If they are still present check the bearings on the main motor arbor for wobble. A run out of .005" will generate chatter marks. Check the guides for the main saw as well. Also different melamine brands will result in different cutting methods. You said that a resharpened blade cuts better. This could be a result of a narrower tooth cut after sharpening. Ask your vendor what they do and what type of blade best suites your application. Cutting 5 sheets at a time is no problem for good horsepower but not all blades can stand up to the test.
From the original questioner
I do not think that it is heat related because we have this problem as soon as we put the blade on the machine. And, it is pretty chilly in this part of our shop. Some blades seem to work better than others. And, some brands and colors of Melamine are better or worse than others as well.
From contributor B:
Did you try slowing down your feed speed a little? Is the blade being sharpened properly? Are all the teeth there and in good shape? Try FS Tool - they make a long lasting blade. I've had good luck with mine, although they are a little noisy. I have not had as good of results with others.
From contributor C:
Check your blade (saw) for parallelism between it and the cutting line. Your saw manual should have a section that describes how to do that by cutting some coated panels in a specific way. I doubt if there is a problem with your blades when they are new.
From contributor D:
I have said it here before - as melamine ages (before or after it is applied to substrate) it becomes more brittle. This aging takes place in a matter of months. The brand of melamine can make a huge difference too. In my personal experience I found Linneman papers to be a superior product.
Another cause for your zipper cut can be your book height on the saw. Try cutting the exact same pattern & material when you see it happening, with one less sheet on the stack. The reason behind it is that your blade is not getting enough penetration above the book and the teeth do not engage properly, thus tearing the material rather than cutting it.
From contributor C:
If the aging described has the effect that is attributed to it, then we are all screwed. We have cut melamine-coated panels that are well over a year old without any problems. We have also cut panels that are few days old and we have had chipping problems with it. While the properties of the melamine might affect the cut quality, it is most likely to be the saw or the blades causing the problem of poor cut quality (not wear, however).
The most common issues I have had with melamine-coated panels is the existence of high and low areas that allow the melamine to chip between sheets in a book.
From the original questioner:
To contributor C: It is interesting that you mention bad cuts between a book. We have had a problem with this in the past and it turned out to be the rubber gasket material on the beam. I do not think that the problem has anything to do with the age of the melamine because most of it is special ordered and we are cutting it as fast as we can get it. Now, I have noticed that some brands of Melamine scratch much easier than other. When we have had a problem, switching blades has solved the problem. As far as having problems related to how far the blade is over the top sheet, our saw carriage has several stops that regulate the height of the blade depending on the cutting height. We have the same problem with one sheet, two, three, four or even 5 sheets. But, changing blades takes care of it. My sharpening guy picked up 4 sets of blades today to re-sharpen although they have not been used since he ground them last week. He said he will run them himself. Hopefully that will take care of the problem. Otherwise, I think I need another company to sharpen our blades.
From contributor E:
Maintaining your beam gasket with material of the correct hardness will help your beam to compress the book. Also, maintaining the throat plates will affect the book compression.
We had a brand name shop sharpening our blades. After just a few sharpenings new blades would look so wrong that even somebody who never saw a saw blade could compare them to a new blade and see the were not correctly sharpened. Don’t trust your sharpener to do the correct job until they have clearly demonstrated that they are capable of maintaining the blade spec when sharpening. This is also true of router bit sharpening.
From contributor F:
What brand, model, size is your saw? Could it be that you are just over working the saw? Our Holzma has a 3" book height but if I need a perfect cut I will only cut 2 sheets at a time. Like someone mentioned, if you look at what % of that blade is buried in 3"+ of MDF and melamine you might find the saw is working pretty hard, unless you have a big machine. We cut about 200 sheets a day and our blades last 2 weeks or so. Granted that's usually 1-2 sheets at a time because we're a custom shop, but once a day is just not right. I hope you find the solution.
From contributor G:
We had some problems with chipping. I don’t know if this will help you, but we weren't able to adjust our saw height with our beam saw so instead we opted for a smaller blade and flat top our scriber this fixed a lot of our problems.
