Roll Slitter Blades and how to care and sharpen them.
If you own a roll / lathe slitter you probably already know the importance of a sharp slitter blade or knife. A dull knife produces more drag, more heat and will place an extra strain on your entire machine. Most of all dull slitter blades produce poor cuts which results in an inferior product or in some cases ruined rolls.
It is sometimes difficult to tell if log slitting problems are coming from a dull blade or from other issues. Before having your blade sharpened check it to see if there are any nicks or burrs that may be affecting your cut. Also, take some adhesive remover and wipe the slitter knife blade down and then wipe that off with a clean cloth. Adhesive build up on a blade will give you poor cuts. Adhesive can also be cleared by taking a razor blade type knife with a holder and running it along the knife / blade edge while you manually turn the slicer blade. Sort of like removing decals from glass with a razor blade. I normally do this and then apply some adhesive remover and then wipe down. Depending on what you are slitting it is sometimes helpful to wipe the blade down with a thin coat of grease. This keeps adhesive and other contaminants from sticking to the blade and keeps it lubricated. A misting system should do the same thing if your machine has one.
If you have tried these steps and are still getting bad cuts or believe your blade is dull you can try sharpening it yourself with a hand held knife sharpener or wet stone or you can remove the blade and send it in for sharpening. Keep in mind that many local machine shops will sharpen blades for you which will prevent you from having to mail the blade in. It is a good idea to have two blades so that your machine is never down. While one blade is at the sharpening shop the other is working. If you are lucky enough to have an automatic blade sharpener then just make sure it is adjusted correctly and keep an eye on how large your blade is. As it is sharpened it gets progressively smaller over time and will eventually need to be replaced.
There are several places to get blades. If you can get them straight from your machine manufacturer that is probably the safest way to go. Other companies also sell blades and will often have you copy and fax a picture of the blade to them so they can determine the size. This way you keep the blade and save at least some shipping. They will also need to know whether your blade is a single or double bevel.
Your blade life will depend on what you are slitting with your roll slitter. Some materials have little effect on the edge and some have a drastic effect. A good replacement plan will minimize down time and will assure good clean cuts everytime which is the ultimate goal of roll converting.