Good day all.

I have already read a thread about melamine warping after cutting that was posted over 10 years ago. I am looking for any advice.

I'm going to use metric measurements.

So the problem is that whenever we are cutting thin, long pieces of melamine, it tends to bow or warp. Now this really isn't that big of an issue, because we mainly use these pieces for cappings, kickplates and fillers. The issue comes in when we are cutting long doors that are 300mm to 595mm.

When 2 doors of the same size is next to each other, the top and bottom touches, but in the middle there's about a 4mm gap. It makes the finishing process so much longer and difficult.

So I was wondering if anybody can help me to understand what we are doing wrong and what can we do to get more straight cuts.

If there's any uncertainty or questions. Feel free to ask.

Have you tried other materials? If the same thing happens on other panel products then it is a machine as vs. material problem.

BH Davis

When I cut long narrow pieces on the saw I will cut oversize then a straightening cut and finally to size. Judging by the date stamps on the sheets I get, the time the sheets to acclimatize after production can be a few days by the time they are on the floor at the distributor. No wonder there is tension in the sheets.

This could be internal stress in the melamine veneer causing the sheet to bow during the cut. Using the correct blade and feed settings may help.
For melamine sheets, use a high-quality three-piece blade or ATB (alternating top bevel) blade with a high number of teeth. Then set a slow and steady feed rate to reduce vibration or heat.
In terms of cutting order, try cutting the larger sections first and the thinner sections last to reduce the possibility of stress accumulation in the middle of the sheet.

Hi BH Davis

The warping happens on MDF as well, but not to the same extent as melamine.

Same with Formica or post form tops. It bows with 1mm in the middle.

Hi Tom

Yeah we usually do that as well. Let us say that we need a filler that's 100mm. We cut it a 110mm and then we edge it. After that we cut it to the correct width. But it still bows.

I'll see if I can post a photo.

Lets see if this works.

Hi Acctek

Thanks for the advice. I'll pass it on to the operators. We will try out a new blade with higher teeth and ATB.

I recut everything. Plywood not as bad but it can do it also. Problem is you never know until you cut it. When I first starting using a slider 30 years ago I was told to take a 1/4” off of long side of melamine sheet and this would relieve tension and subsequent cuts would be straight, I have never found that to be true. Solid lumber no different, sometimes bow sometimes not. If I’m looking for 2” wide I oversize some, straighten and then rip to width I want.

Hi Al

Thanks for the advice. We have gotten one of the reps from the manufacturer to come and look. He took the old boards and replaced them with a new batch.

It seems to have worked. The pieces still bow, but not as much.

Hopefully it was a bad batch.