The goal of a sheetfed offset printer, like every printer, is to produce printed pieces efficiently and economically. In sheetfed offset coating applications, selecting the right doctor blade will help keep presses running and minimize costs while maintaining a safe pressroom environment. By replacing steel with non-metallic doctor blades, a printer can reduce pressroom injuries, eliminate anilox roller scoring and extend blade life.
Three reasons to replace your steel blades with non-metallic doctor blades:
1. Pressroom Safety
Steel doctor blades are responsible for a large number of pressroom injuries each year. As the blades wear, their edges become honed through contact with the anilox roller. This leaves razor-sharp tips that can cause serious cuts. Press operators need to be extremely careful and wear protective gloves when removing the worn blades from the press to avoid injuries. Due to their material composition, non-metallic doctor blades are safer to handle even when worn. Switching to non-metallic doctor blades will reduce lost-time accidents and can save a printer a lot of money in terms of workman’s compensation insurance rates, medical bills, labor replacement expenses and press downtime.
2. Anilox Roll Scoring
Steel blades are also to blame for many cases of anilox roll scoring. Incorrect blade installation or too much blade pressure can cause small fragments of metal to break away, become trapped against the roller and destroy rows of anilox cells as the roller turns. The score line appears as a thick band which runs around the circumference of the roller and affects the corresponding area of coating coverage. The printer wastes substrate and coating and has to have the roller resurfaced or replaced at a significant cost. In addition to scoring, steel blades accelerate wear on the surface of the anilox roller. The friction between the blade and roller erodes the anilox cell walls. As a result, the cell volume is reduced and the anilox roller can no longer carry the precise volume of coating that it was designed to deliver. Non-metallic blades are non-abrasive and will neither score rollers nor cause accelerated wear on the anilox roller.
3. Blade Life
Steel blades wear quickly and need to be replaced frequently. Non-metallic blades, on the other hand, have a long, slow wear period and deliver a consistent application of coating for the duration of the print job. They have a low coefficient of friction which means they need to be changed out less often. By switching from steel blades, a printer can minimize press disruptions and keep presses running longer.
For sheetfed offset printers using in-line tower coating units, there is a non-metallic blade available for every application. Tresu and Harris & Bruno chamber users can opt for the TruPoint Orange® blade with MicroTip® edge – a blade capable of effective metering with the added advantages of improved safety, reduced anilox roller scoring and longer blade life.