Higher Output and Improved Quality New Developments at Dienes Werke

Important parameters to initiate a winder or sheeter upgrade for example are, the weight of the material to be slit, the operating speed, the level of automation the availability of technology and the quality of the end product.

Knife metallurgy, knife grinding, knife coatings as well as the end users existing system are decisive factors regarding the degree of automation.

Dienes Werke in Overath a company specializing in the design and manufacture of slitting tools and systems has developed complete cutting units based upon modular designs. Using these designs allows upgrading and the modernization of a winder, which will drastically increase productivity as well as quality. It is possible to select between several different modernization levels.

For example, it is possible to realize a manual, semi automatic or fully automatic knife positioning arrangement, or the implementation of a cassette type installation, or the utilization of torsion free shear cut knife holders for an almost dust free slitting environment.

In addition Dienes offers a large variety of special knife holders for product weights of up to 1000 g/m_ and torsion free shear cut knife holders allowing the determination of the exact location of the cutting point as well as the setup of the top and bottom knife geometry depending upon the material to be cut and the number of paper layers processed simultaneously.

Numerous end users can no longer accept the knife wear obtained by using knives made from basic alloy tool steels and high Chrome steels. Knife wear as well as the cutting results do depend a lot on the selection of the knife geometry.

"Golden Slit" is a newly developed knife, offered by Dienes. The uniqueness of this knife lies in the machined slots in the knife body. The meander like configuration and the circular holes creates a spring like effect, which almost entirely eliminates critical vibration during the cutting process. The springs as a part of a complete knife assembly are no longer needed.

To increase knife wear, Dienes offers increasingly knives made from new knife metallurgies. Depending upon the application, cutting processes can be made by using coated knives or knives with tungsten carbide or ceramic inserts.

To drastically reduce the formation of dust during the cutting operation, Dienes offers a polished surface finish in addition to the standard grind and surface finish.

Dienes also works with a coating process for top knives, which penetrates deep into the knife material. This allows regrinding these knives almost as often as untreated knives. The higher price for these knives will be amortized over a short period of time, since the knife wear is drastically increased.

To even increase knife wear further, especially when processing materials, which are difficult to cut, it is recommended to use bottom knives with tungsten carbide inserts. A comparison, made under the same conditions, between tungsten carbide inserted knives, for example G 30, and bottom knives made from alloy tool steel (for example the Chrome steel 1.2067) shows, that tungsten carbide inserted bottom knives last eight to ten times longer depending upon the grain size.

The best knife wear is achieved, when using ceramic inserted circular bottom knives as a part of a slitting station in a winder or sheeter.

Compared to tungsten carbide bottom knives, the ceramic knife wear will increase by two up to three times. Depending upon the slitting application it is recommended to match the physical values of the ceramic according to the application.