Project
Improving the quality of industrial knives (QUALIKNIFE)
Industrial knives are used for
many processes in the technological industry. These are cutting,
shearing and punching tools usually made of high-quality steels and
heat-treated to increase strength and resistance to wear. The lifespan of these
knives strongly depends on the application and the material that is cut with them.
Knives for plastic and paper undergo different loads than knives used to cut steel sheets. For
example, hard particles or fibers are often processed in plastics and
composites. However, these additives are detrimental to the cutting blades
because they increase wear. This necessitates early resharpening or replacement
of the blades. In the case of metal products, high-strength steels pose a
similar problem.
This Collective R&D and Knowledge
Dissemination project aims to provide a solution by responding to three
important parameters for knives, namely: the material, the surface treatment and the core treatment.
The Material – Of course, the choice of the material for the substrate is one of the most important
parameters when using industrial knives. New steel grades such as powder
metallurgical (PM) steels can help to increase the tool life and to solve many
cutting problems. However, the associated heat treatment of the substrate is
also at least as important for the end result.
Surface treatment – Sirris has
built up a great deal of experience in the past with laser treatments of steel
surfaces, such as laser hardening (eg the cutting edges using diode lasers) and
laser texturing of surfaces. With laser hardening, the steel surface is
converted into a hard layer without any change in size or shape, which
significantly increases wear resistance. Recent tests of laser hardened blades
have shown more than a doubling of life. In addition to the increased surface
hardness, it also reduces the adhesive effect of, for example, plastics on the
cutting edge, resulting in improved cutting quality. A third advantage is the
introduction of compressive stresses through laser hardening,
Laser texturing on the other hand will positively influence the topography of the
surface. For knives, a laser texture will ensure that the friction between chip
and knife decreases, reducing heat development, wear and cutting force, which
in turn improves the service life. Ultrashort pulsed lasers will also not
affect any heat treatments, and will not negatively affect the microstructure,
making a combination of hardening & texturing possible.
Thin hard coatings, type PVD and PACVD, possibly also in combination with a nitride 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, which significantly increases the abrasive wear resistance and thus the life of a knife. In addition, these layers 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 end product.
Treatment of the core – In addition, there is also a special cryogenic heat treatment that acts on the substrate, namely deep cooling after solid hardening. This technique, known for 30 years, is rarely used but can provide a sustainable solution for many problems related to wear and life of tools. While laser hardening mainly transforms the surface into a hard edge layer, deep cooling will have an effect on the core of the material. Recent research projects have shown that the service life of punches for metal and plastics is significantly increased by this treatment. The advantages of deep cooling are mainly related to the internal structure: higher hardnesses, secondary separation of fine carbides and reduced internal stresses provide better performance after deep cooling mainly in terms of wear. Some researchers have even observed an improvement in the corrosion resistance of hardenable stainless steels after deep cooling.
In summary: there are several
innovative solutions for extending the life of industrial cutting tools:
Use of alloyed PM steels: purer and more
homogeneous steel
DCT or deep cryogenictreatment after hardening: increase of wear
and corrosion resistance due to lower residual austenite, finely dispersed carbides and low internal residual stress
Laser hardening: high hardness, local and
precise edge hardening without deformation
Laser texturing: better roughness control,
low frictional resistance, better chip and heat evacuation
Coatings: higher abrasive and adhesive wear
resistance, low frictional resistance.
Our project QUALIKNIFE wants to evaluate
the available technologies to increase the lifespan and performance of knives
and make them accessible to the Flemish industry. An infrastructure will be set
up within the project to share knowledge, set up demonstrators and guide
companies through their business cases and field trials. The intention is to find a solution
on a case-by-case basis based on one or more (combinations) of the 5
technologies mentioned above.
For whom?
We focus on producers and users of
industrial cutting, shearing and punching tools for processing steel, plastic,
rubber, wood, paper, composites and food… Many companies use knives and shears
in their processes and have all interest in increasing uptime and avoiding
downtime.
What companies can expect:
* a casebook with inspiring examples and
guidelines
* regional seminars demonstrating the
challenges and solutions
* gaining insights and guidance to take the
first steps within your business environment. The actually feasible technical
improvement must be investigated per industrial case.
Normal 0 false false false en-BE X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0cm; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-font-kerning:1.0pt; mso-ligatures:standardcontextual; mso-ansi-language:#0C00; mso-fareast-language:EN-US;}
The
potential of innovative techniques and materials for industrial knife applications
was demonstrated on the basis of six generic cases. Various topics were
discussed in these cases:
• use of high-quality newly developed steel
types
• improvement of the properties by means of deep cooling of the blades
• laser texturing to reduce surface adhesion
• application of coatings to improve wear resistance
• ultrasonic cutting as alternative cutting technique
Two online webinars were organized with speakers from the value chain (knife
suppliers, practitioners) and presentations by Sirris on new technologies and
results of the generic cases.
A casebook was also drawn up that collects a large number of practical examples
and documented cases of 'best practices' for industrial knife applications.
This casebook helps companies in the sector to make the right selection of
material and possible after-treatment for their specific application.
In addition to these collective actions, 23 company-specific implementations
were also initiated and supervised.