When using a paper trimmer we all know and understand that it is very important to keep the paper cutter blade sharp. This is the only way to ensure the most accurate and straight cuts.
Paper cutters, no matter the width or thickness of the cut, all use a wide guillotine-style blade to drive through the paper stack and cut into a nylon cutting stick on the cutter bed. The cutting stick ensures the blade can go through every piece of paper. When the blade blunts through constant use, the paper begins to be “pushed” instead of sliced and it can lead to an uneven and unacceptable cut. When printers and paper handlers are dealing in cuts measured in 1/1000ths of an inch, a blade sharp as a scalpel is imperative.
Removing the blade
The blade cannot be sharpened on the paper cutter, It must be removed. Doing so means lowering the blade and stopping it in the down position before it returns. Paper cutters have a setting for doing this procedure. The blade is held in place by a series of bolts (usually Allen bolts) across the blade's face. Remove each one from the outside to the middle: left, right and repeat until the centre bolt or bolts remain–depending on whether it's odd or even number of bolts.
When this is completed, return the guillotine to its “up” position and the blade will free. Some blades are so large they need two handles screwed into corresponding sockets in the blade face to remove. Do so if necessary.
Sharpening the blade
How to sharpen a paper cutter or paper trimmer – Paper cutter blades are different in make and model. The most important difference is the blade angle. This is the angle of the cutting edge to the face of the blade. Sharpening must match the specified blade angle for the cutting machine model. If the pitch is too shallow or too steep, it can affect the cutting performance and the motor power driving the blade mechanism. Check the specifications for the machine for the proper blade angle.
Blades can be sharpened manually using a grinder, file or even a stone. Quite honestly, though, this can take an inordinate amount of time. Imagine sharpening a pocket knife only a hundred times larger. Also, manually sharpening a blade can lead to an inaccurate blade angle mismatch. What is best is to pack the blade in a protective sheath–just wrapping with two sheets of cut plywood will do well–and take the blade to a professional saw and blade sharpening shop. Although available in most larger cities, it may mean shipping the blade off for sharpening. The good news, though, is rarely if ever does a cutting machine not have two blades: one that's sharp and ready to install while the other is being sharpened. Then in a few weeks or months with the installed blade is dulled, replace with the newly sharpened blade.
Installation of a sharp blade
Installation is just the reverse procedure of removal: bring down the guillotine, insert the blade and attach the bolts from the inside to the edges. When doing this, however, check to make sure the blade is level and contacts the cutting stick at the same time from side to side. Also, don't forget that sharpening takes a little off the blade. After installing, adjust the depth of cut a few thousandths of an inch or millimetres to compensate for the new blade size. Eventually, the blade will be sharpened back to where maximum depth of cut will not touch the cutting stick. When this happens, it's time for a new blade. Don't worry, though: it takes many years and many sharpenings for this to happen.