With the eKnife, TKM is introducing a new cutting knife concept to the market that aligns the features for cutting books and brochures more closely with the principles of sustainability, innovation, and technology.

Today, the cutting blades used are typically available in carbide and steel, bonded using traditional joining methods such as soldering or adhesive bonding. Both methods—which, incidentally, are also used by TKM—have advantages and disadvantages. Soldering achieves a tensile strength four times greater than that of adhesive bonding; however, the straightening effort required for an adhesive-bonded blade is significantly lower. In terms of cost, the two joining techniques are comparable; in some cases, glued blades are even more expensive to produce.

The blades used for cutting books consist of a 20–30 mm high-alloy insert (carbide or steel) bonded to a substrate made of C45 steel. These blades typically weigh approximately 4–6 kg each and, depending on the application and wear, can be resharpened 25 times or more. Each resharpening removes approximately 0.5 to 1 mm from the blade’s width, and after the final resharpening, the blade must be replaced with a new one.

The Impact of Greenhouse Gas Emissions on the Manufacturing of Knives for Industrial Use
When replacing a knife, it is important to note that industrial steel production emits approximately two metric tons of carbon dioxide for every metric ton of steel produced. This accounts for about 10 percent of global CO₂ emissions. In other words, replacing a 6-kg blade results in the emission of 12 kg of harmful greenhouse gases. Most steel companies have committed to a significant reduction in CO₂ emissions by 2050, but at present, we are still a long way from this “green” steel.

The standard blade grades used for cutting books today are the so-called carbide-tipped (HM) blades. In countries and regions where high-quality sharpening services are not available (in addition to sharpening machines, straightening capabilities are also necessary), users are often unable to access tools with optimized service life. As a result, these users rely on tools that wear out more quickly and require more frequent sharpening. For these reasons, they predominantly use simple tools and grades that are selected solely based on the capabilities of the available sharpening service. Occupational safety also plays a key role, as every blade that does not need to be replaced enhances workplace safety at the processing facility.

In most cases, regrinding is handled by a regional service partner who specializes in picking up dull blades and delivering sharp tools back to the customer. Service vehicles travel several hundred thousand kilometers per year for this purpose; in 2022, trucks with a load capacity of 3.5 to 7.5 metric tons emitted more than 569 grams of harmful greenhouse gases per metric ton-kilometer.

The TKM eKnife addresses this exact issue. Why not use an insert that’s needed for cutting, and why not use a carrier material that can be reused multiple times? In this case, knife wear is limited to the insert alone. This not only reduces the production facility’s knife replacement costs but also sustainably lowers greenhouse gas emissions. This is gentler on the environment and, at the same time, minimizes costs as much as possible.

TKM revisited this topic four years ago. Previous trials and experiences were carefully analyzed, digitized, and documented. Ultimately, it became clear that there is a solution that is not only sustainable but also innovative. The specifications were revised to redefine the objectives (functionality and cost-effectiveness), and the goal was also to make the products available to a broad market.

The idea behind the TKM eKnife—sustainability and the reduction of CO2 emissions in the industrial production of books
The TKM innovation is based on a classic carrier/blade design; the blade is clamped into the carrier, thereby providing the necessary stability. The knife concept is based on TKM collecting used tools for regrinding and returning sharpened knives to the customer. Only the replaced blade is ground; the user continues to use the holder indefinitely.

The blade weighs approximately 10% of a conventional knife; thus, the eKnife significantly reduces emissions. The carrier is reused, which also helps to sustainably reduce emissions associated with replacement purchases.

Field tests were conducted at a renowned German printing group responsible for a large portion of all printed books in Germany. Not only were the results documented in the field, but the eKnife also proved its worth even with large production volumes. The results are in no way inferior to those of conventionally manufactured knives.

The eKnife variants (1 carrier, 3 blade options):
TKM offers the eKnife with the following blade options:

• Standard grind
• New Wave grinding technology for up to a 4-fold increase in service life
• Non-stick coating to prevent glue from adhering to the blade

The carrier continues to be used, and the user can select the blades as needed for their specific applications.

TKM eKnife Blade with Non-Stick Coating
One variant of the TKM eKnife is the TKM Anti Glue Knife (with non-stick coating).

Adhesives (hot melt, polyurethane (PUR), or dispersion) are an essential binding agent in industrial manufacturing, for example, in the production of adhesive-bound books (paperbacks and photo books). After the spine or pages have been glued, the products are cut to size. Often, the adhesive has not set before cutting and accumulates on the blade (both the cutting edge and the back edge) during the cut. This places greater stress on the cutting edge; the adhesive builds up with each cut, negatively affecting both the cut and the cut quality.

In such cases, the blades are typically cleaned manually with oils or solvents, which prolongs the work processes and reduces productivity. Built-in spray systems, which also frequently use silicone oils, provide a certain degree of relief. However, depending on the frequency of the spray intervals, this lubricating emulsion leaves a greasy film on the blade surface. As a result, the user often has to replace the blade prematurely after just a few cuts.

TKM offers the eKnife blade with an optional non-stick coating. This simplifies operations at the printing plant and significantly improves the efficiency of blade use. The surface of the TKM eKnife blade with a non-stick coating is characterized by a low coefficient of friction combined with greatly reduced adhesion properties.

TKM eKnife blade with New Wave grinding; extend your blade life up to 4 times
70% of all cutting problems and customer service requests (complaints) are attributable to inadequate knife sharpening quality. The TKM sharpening service concept is designed to offer customers innovative sharpening techniques that guarantee operational reliability, workplace safety, and reproducible results. Most contract and service shops operate using conventional sharpening techniques. In this process, the blades are sharpened using what is known as pressure grinding, or disc grinding. During this process, the grinding wheel operates over a large surface area with high thermal stress.

Scientific studies have shown that this causes the sensitive cutting edge to become rougher and, in some cases, develop cracks. Disc grinding typically removes more material than is necessary.

Many years ago, TKM introduced the so-called “New Wave” sharpening method to the market. This is a longitudinal or peripheral sharpening method that treats the sensitive blade edge much more gently. Only approximately 0.3 mm of material is removed per sharpening operation. Compared to conventional disc-grinding techniques, this represents a reduction in material removal of 40% or more. Cutting tools can be sharpened more frequently using the New Wave technique, thereby significantly reducing blade replacement costs.

Field tests have confirmed that the New Wave grind can achieve a service life that is 3–4 times longer. Particular advantages and improvements in service life are evident when using dispersion adhesives or products with solid-color coatings.

The New Wave technique plays an important role in sustainable blade and grinding technologies. The slightly higher costs associated with grinding and the potential need to purchase new blades are more than offset by significantly longer service life and significantly fewer blade replacement intervals.

Summary
The concept can be used and applied to a wide variety of blades and applications. The resulting benefits for the user and the environment are innovative, sustainable, and timeless. With a weight reduction of nearly 90% compared to conventional blades, emissions can be significantly reduced in the future without compromising cutting quality.

Schedule a consultation with the TKM experts today—we’d be happy to introduce you to the eKnife and demonstrate the long-term benefits it can deliver in industrial book production.