Knife sharpening in the printing industry

04 Jan 2023
ostrzenie noży do krajarek

The 21st century is the age of digitization. All information, articles, news, publications, as well as entire novels are available in the electronic version. Many people decide to buy tablets or e-books to have their favorite books in one handy device. Despite this, the production of books in the traditional form is still at a very high level, and bookstores continue to enjoy great popularity among consumers. For many people, nothing can replace a paperback book. Printed copies tempt us with beautiful covers, pleasant to the touch texture and unforgettable smell of pages. The atmosphere of reading a book late in the evening with a cup of hot tea cannot be replaced by anything else.

Usually, we associate the production of books in printing houses mainly, not without reason, with printing. However, the process of creating a book consists of many activities. No less important in the production is the act of "cutting" the books into the shape in which everyone knows them. And here the most important role is played by printing knives, used e.g. in cutters and trimmers, which must be perfectly sharp for the paper cut edges to be perfect.

This is where our knife grinding machines and their very important role in book production come in.



The Interdruk SA printing house can boast of being the largest in Poland. It is located in Gawrolin, 60 km. from Warsaw. The plant was founded in 1991 and since then it has operated as a small enterprise. Currently, it occupies as much as 10 hectares, with 40,000 m2 of production halls and 12,000 m2 of warehouse space.

The company, like many others, struggled with the problem of sharpening industrial knives. In this respect, it was dependent on external suppliers, which was associated with fixed service and logistics costs. Added to this was the waiting time for a sharpened knife.

After analyzing all the pros and cons, Interdruk decided to invest in the purchase of its own grinder for sharpening industrial knives.


In December 2020, the Interdruk printing house asked us for an offer for a machine for sharpening industrial knives.

Our product was particularly suited to the needs of the company. Attention was drawn to the fact that we offered a solid grinder, built on European components and fully assembled in Poland. Our machine matched the quality of machines from Western suppliers, being at the same time a much cheaper and more easily available product, due to the country of origin.

An additional advantage was also the fact that for over 12 years, as a grinding shop, we have been sharpening knives for the printing industry in a continuous mode, in particular knives for paper cutters and tripods. In sharpening this type of knives, the precision of the sharpening itself is very important, as well as the know-how regarding the proper finish of the knife blade. We will try to show how important this is below.

Let's imagine, for example, that when we choose a beautiful thick hardcover book in our favorite bookstore, we notice visible "scratches" on its sides or torn edges of the pages ... Unacceptable! The knife must be perfectly sharpened so that it does not leave even the slightest unevenness in the process of "cutting out" the book. It is thanks to such knives that we can enjoy the eye with smooth and even page edges, and this is the effect that work on GRAFS machines guarantees.

There are many factors that affect the sharpening quality of such knives. One of the basic ones is the quality and precision of the machine itself that sharpens the knives. However, there are also many other factors, such as properly selected grinding wheels for knives, coolant quality and concentration, proper coolant filtration, machining speed, but also the experience of the person who operates the machine and then prepares these blades for work. It is worth mentioning here that a standard knife for a paper cutter can be 160 cm long and weigh about 25 kg! The issue of sharpening such a flawless knife is therefore quite a challenge.

We proposed a GRAFS GR model tailored to the needs of the Interdruk printing house. The company needed help in implementing the sharpening system, which is why, as for each of our clients, we offered help in building the entire system from scratch. We traveled to Garwolin to train the staff in operating our machine at their place of work and we helped in the selection of all necessary accessories.

We invite you to see the work of GRAFS GR in the printing house of Interdruk S.A.