How to increase the uptime of industrial blades and avoid shutdowns

Industrial blades are used for many different processes. Their service life depends to a great extent on the application. A new COOCK project aims to offer a solution by studying the crucially important parameters of material, surface treatment and core treatment.

Industrial blades are used for many processes in advanced manufacturing industries. These blades take the form of cutting, shearing and punching tools. They are usually made from high-quality steels and heat-treated to increase their strength and resistance to wear. The service life of these knives depends greatly on the application in question and the materials that are used to shape. Blades for cutting plastic and paper experience different loads from those that cut steel sheet. For example, plastics and composites often contain hard fibres or particles. These additives are detrimental to the cutting blades because they increase wear. This makes early and regular re-sharpening or replacement of the blades necessary. In the case of metal products, high-strength steels pose a similar problem. 

The 'Collective Research & Development and Collective Knowledge Dissemination (COOCK)’ project QualiKnife aims to solve this by responding to three important parameters for blades: the material and the treatment of the surface and core.

Materials

The choice of material for the substrate is naturally one of the most important parameters when using industrial blades. New steels such as powder metallurgical (PM) steels can help increase service life and solve many cutting problems. The associated heat treatment of the substrate is at least as important for the end result. 

Surface treatment

Sirris has built up a great deal of experience in the laser treatment of steel surfaces, including the laser hardening of parts by laser texturing surfaces and hardening cutting edges with diode lasers. In laser hardening, the steel surface is converted into a hard layer without any change to its shape or dimensions, which significantly increases its wear resistance. Recent tests of laser-hardened blades have shown more than a doubling of their service lives. In addition to the increased surface hardness, it also reduces the stick-slip effect of, for example, plastics at the cut surface, resulting in a higher quality cut. A third advantage is the introduction of compressive stresses by laser hardening, which prevents cracking and, in turn, extends the life of the component. 

Laser texturing will then have a more beneficial effect on the surface topography. Laser texturing extends the service life of blades by reducing friction between chips and blades, which lowers heat generation, wear and cutting force. Ultra-short pulse lasers will also not affect any heat treatment or adversely affect the microstructure, allowing a combination of hardness and textures. 

Thin, hard coatings of the PVD and PACVD types - possibly also in combination with a nitrided layer - also greatly improve the cutting, shearing or punching process. These coatings are applied to hardened base materials and form a very thin and very hard ceramic layer that considerably increases the abrasive wear resistance and thus the service life of a blade. These layers will also reduce the frictional resistance and prevent the material to be cut from sticking or cold-welding to the blades. This increases the quality of the finished product.

Treatment of the blade core

There is also a special cryogenic heat treatment that acts on the substrate: deep cryogenic cooling after hardening. This technique, which has been known for 30 years, is rarely used but can provide a durable solution to many problems with wear and tool life. Unlike laser hardening, which mainly transforms the surface into a hard edge layer, deep cooling mainly affects the core of the material. Recent research has shown that this treatment considerably increases the service life of punches for metals and plastics. The advantages of deep cooling mainly derive from the internal structure: higher hardness, secondary precipitation of fine carbides and reduced internal stresses ensure better performance, especially in terms of wear. Some researchers have even found an improvement in the corrosion resistance of hardenable stainless steels following deep cooling.

The QualiKnife project

The QualiKnife project, starting in January 2021, aims to evaluate the technologies available for extending the service life and performance of blades and to make these technologies accessible to Flemish industry. The project includes setting up structures for sharing knowledge, setting up demonstrators and assisting companies with their business case and field trials. The aim is to find a case-by-case solution based on the above-mentioned technologies, either singly or in combination.

For whom?

We are targeting the manufacturers and users of industrial cutting, shearing and punching tools that are used for working everything from steel, plastic, rubber, wood, paper and composites to food ... Many companies use blades and shears in their processes and have a great interest in increasing uptime and avoiding shutdowns.

What companies can expect

  • A casebook with inspiring examples and guidelines
  • Regional seminars demonstrating the challenges and solutions
  • Insights and guidance in taking the first steps within your business environment 

The technical improvement that is actually feasible needs to be determined on a case-by-case basis.

Are you interested in this project or do you have questions about the topic? Then don’t hesitate to get in touch with Bart Teerlinck or Guy Claus!

QualiKnife is a COOCK project, supported by VLAIO.



(Picture : example of industrial steel knives - source: http://www.machine-knife.com)