DE3734781A1 - Process for producing a layer with sharpening effect on cutting edges of shear blades - Google Patents

Abstract

The invention relates to a process for producing a dispersion layer with a sharpening effect on the cutting edges of shearing machines for human, animal and synthetic hair, and other shearing machines, and also on cutters in machines in the food industry, process engineering and in agriculture. The process may be carried out either electrochemically or by the application of a plastic matrix. In addition, in the process description given below, reference is made to the possibilities, improved by us, for producing dispersion layers.

Description

Current state of the art

The cutting blades on the machines mentioned above are ground as parallel as possible today. Even with the most precise production, they are Cutting edges of the shaving blades have a limited shelf life. The cutting edges are deformed and in use rounded off, leading to a decrease in cutting ability leads.

To restore a usable condition, the tools must be disassembled and reworked be prepared.

We want to counter this disadvantage with our invention by using an electrolytic process to build up a dispersion layer, which brings about a continuous, automatic re-sharpening of the shear blades.

¹) Dr. Heinz W. Dettner and Dr. Johannes Elze: Handbook of electroplating, volume 1, 2, Carl Hanser Verlag AG., Munich, 1967

Electroplated dispersion layers are after ¹) previously used for other purposes:

• - Coatings to increase wear and abrasion strength
• - Dispersion hardened coatings
• - porous layers
• - Coatings to improve corrosion protection.

According to OS 22 30 676 from June 23, 1972, e.g. a wear and tear solid layer, which is characterized by that embedded in a metal matrix diamond particles are.

Dispersion coatings with built-in abrasives are among others applied to the following articles:

• - Diamond coated files (e.g. for tool making)
• - Nail filing
• - Dental instruments
• - Polishing, grinding and cutting tools.

All of these dispersion coatings are not intended to effect an automatic re-sharpening of shear blades.

the solution of the problem

The invention relates to a galvanic method for Production of a dispersion layer with automatic, resharpening effect on cutting edges of shear blade of any kind.

Due to the relative movement of the blades against each other which are in the applied dispersion layer Exposed abrasive particles that regrind the Effect cutting edges.

This presupposes that a high density of grinding par Articles contained in the matrix is that good Ensure liability of the metal matrix on the base material is and that the dispersion layer is a good one Ductility and resistance to punctual Has heating.

In the process of constantly resharpening the cutting edges, there is a small amount of material removed At the same time, there are always new grinding particles in the metal matrix are exposed and thus a continuous Process up to complete wear of the shaving blades takes place.

Care should be taken that the middle particle size of the application and the size of the machine corresponds. The size of the particles should, however Do not exceed 100 µm.

There are medium particles in hair clippers proven sizes of up to 3 µm.

The proportion of those contained in the dispersion layer Particles should be up to 60 vol%, preferably from up to 40 vol.%.

The particles to be embedded can be around:

• - atomic solids such as Diamonds, glass coals fabric and tungsten  
• - molecular solids such as Aluminum oxide, silicon carbide, boron carbide, PTFE, PVDE and triple
• - viscous liquids such as Glass, high molecular weight Polyglycols
• - through targeted growth of crystal structures or Aglomeration

The particles can be electrically conductive or electrical Insulators. Differences are formed accordingly Liche dispersion layers, which are thereby divorce that on the electrically conductive particles also attach metal atoms to the matrix (see ¹).

Grindable structures can also grow of porous metal layers or by etching will.

The layer thickness of the dispersion layer should be at least at least 30 µm are required for uniform grinding to achieve.

The metal of the galvanic deposit is advantageous is a metal or metal alloy following elements:

• - antimony, lead, cadmium, chromium, iron, gold, indium, Iridium, cobalt, copper, molybdenum, nickel, palladium, Platinum, rhodium, silver, tantalum, titanium, vanadium, Bismuth, tungsten, zinc or tin.

As alloy additives e.g. Elements like boron, Phosphorus, rhenium, osmium, arsenic, etc. can be used.

The invention provides that for the production of this Dispersion layer the workpieces to be coated must be thoroughly cleaned and activated. This happens with an electrolytic degreasing subsequent anodic treatment in acidic Electrolytes (see ¹).

After thorough rinsing of the workpieces, a Activation in an aqueous solution consisting of  Nickel chloride and hydrochloric acid (see ¹).

The activation can also differ from this before blow. That depends on the process basic material.

Then the actual application of the dispersions takes place layer in a galvanic bath.

The construction of such baths is already in ¹) wrote.

The dispersion layer can be deposited by different types of current occur (see ¹). We used the following technology:

• - cathodic degreasing in an alkaline electro lyt, 10 V, 10 A / qdm, electrolyte agitated, 3 minutes long, at room temperature, silicate-free.
• - Rinse in water.
• Electropolishing in a phosphoric acid solution at RT, 2 minutes, at 50 A / qdm. (depending on the reason used material can also be a different recipe of electro polishing solution can be applied).
• - Rinse in water
• - Pickling in a sulfuric acid solution
• - Rinse in water
• Activation in a solution containing nickel chloride, For 6 minutes, cathodic, 2-3 A / qdm.
• - Application of the dispersion layer in a solution of the following Rp .:
  Nickel sulfamate 200 g / l, nickel sulfate 200 g / l, ammonium chloride 10 g / l, total organic additives 8 g / l, deionized water and 30 g / l e.g. silicon carbide No. 1500 medium grain size 3 µm, 50-60 degrees Celsius, cathodic and anodic pole change, in a ratio of 1: 1/10 to 1/25, the duration of the cathodic polarity should be at least 1.5 seconds. The ratio of the current density with cathodic polarity to the current density with anodic polarity should be 1: 2, the current density depending on the type of current used and should not exceed 500 A / qdm.
  The deposition time depends on the layer thickness to be achieved.
• - rinsing and drying.

It goes without saying that they are preserved in this way Depending on the purpose, the layers can also be further refined Determination and area of application of the article. For our purposes, this seems to us right now not mandatory.

The manufacturing technology described by us The dispersion layers can be used to achieve others Metal matrix structures are modified by us.

Contrary to the thesis presented in OS No. 22 30 676 we have found that the maximum improvements the wear resistances that sharpen each other the shear blades from galvanic baths with up to 200 g / l finely dispersed solid combinations under the conditions of use of special current types can be achieved. This also applies to the Abbei formation of metal matrix layers, the following property should have:

• - low proportion of gaseous substances
• - high hardness
• - high abrasion resistance
• - ductility
• - good adhesive strength
• - good thermal conductivity
• - good elasticity etc.

This applies especially to base materials that are used in the manufacture shear blades are used.

The basic material for this techno is required good pre-treatment logic. OS 22 30 676 does not exist  Clues to how the base material was pretreated should be in order to ensure optimal adhesive strength, etc. Afford. By the inventors for the purpose of processing of cutting blades using a variety of technologies been checked. At the same time, corresponding galvani cal baths developed. To produce a plastic containing matrix were corresponding by the inventors Technologies created, but these are not further described.

Claims (31)

1. Claim for a method, characterized in that a layer or a combination of layers is applied to shear blades, which causes a continuous re-sharpening of the cutting edges during operation. 2. Claim according to 1, characterized in that it is for shaving blades for clippers for human, animal and synthetic hair. 3. Claim according to 1, characterized in that it is to cutters in cutting units on machines of the Food industry. 4. Claim according to 1, characterized in that it is to cutters in cutting units on machines of the Process engineering is concerned. 5. Claim according to 1, characterized in that it is to cutters in cutting units on machines of the Agriculture is concerned. 6. Claim according to 1, characterized in that it is around shear blades in cutting units on machines for Garden and hedge trimmers. 7. Claim according to 1 to 6, characterized in that it a dispersion layer or a porous one Layer. 8. Claim according to 1 to 7, characterized in that the dispersion layer made of a metal or a Metal alloy or a plastic with inlaid sharpened, conductive or non-conductive grinding par article exists.   9. Claim according to 1 to 8, characterized in that the metal matrix of the dispersion layer consists of an element or a combination of the elements listed below:
Antimony, arsenic, lead, boron, cadmium, chrome, iron, gold, indium, iridium, cobalt, copper, manganese, molybdenum, nickel, palladium, phosphorus, platinum, rhenium, rhodium, sulfur, silver, tantalum, titanium, vanadium, Bismuth, tungsten, zinc or tin. 10. Claim according to 1 to 9, characterized in that the dispersion layer with embedded, conductive or non-conductive abrasive particles in a con concentration of up to 60 vol.%, preferably from to is 40% by volume. 11. Claim according to 1 to 10, characterized in that the dispersion layer contains a polymer matrix, e.g. Polyacrylates, polyesters, polyrethanes, etc. 12. Claim according to 1 to 11, characterized in that the dispersion layer of the polymer matrix up to 60% by volume, preferably up to 40% by volume contains or non-conductive abrasive particles. 13. Claim according to 1 to 12, characterized in that the dispersion layer in a casting or melt is applied and by ultrasound or a vacuum is degassed and then cured. 14. Claim according to 1 to 13, characterized in that the dispersion layer through growth of porous Layers is achieved. 15. Claim according to 1 to 14, characterized in that through the dispersion layer or the porous layer  by etching a metal or metal alloy layer is achieved. 16. Claim according to 1 to 15, characterized in that it is conductive abrasive particles with a medium ren diameter of up to 0.1 mm, preferably of down to 3 µm. 17. Claim according to 1 to 15, characterized in that it is non-conductive abrasive particles with a average diameter of up to 0.1 mm, preferably of up to 3 µm. 18. Claim according to 1 to 15, characterized in that the abrasive particles are, for example, the following materials:
Aluminum oxide, silicon carbide, boron carbide, diamond, graphite, glass, glassy carbon, PVDF, PTFE, PE or combinations thereof. 19. Claim according to 1 to 16, characterized in that the applied dispersion layer or the porous Layer should be at least 30 µm. 20. Claim according to 1 to 19, characterized in that the applied dispersion layer preferably from a nickel matrix or from a nickel alloy tion matrix is created. 21. Claim according to 20, characterized in that the applied dispersion layer preferably not conductive abrasive particles such as aluminum oxide, silicon carbide, boron carbide, diamond, glass, glassy carbon as well their combinations or their combinations with Contains polymers.   22. Claim according to 1 to 21, characterized in that the dispersion layer from an aqueous solution with a share of up to 200 g / l of conductive or non-conductive abrasives becomes. 23. Claim according to 1 to 22, characterized in that the concentration of the dispersed abrasive fen is preferably up to 40 g / l. 24. Claim according to 1 to 23, characterized in that the metals in the electrolytes in the form of water soluble salts or acids are present and a Number of organic and inorganic additives to refine the grain of the metal matrix, the Gloss, inner tension, etc. included. 25. Claim according to 1 to 24, characterized in that the metallic dispersion layers by a Direct current, alternating current, pulsating current or a special stream and their combinations be divorced. (Multi-stage rectifier or Multi-stage transmission generator). 26. Claim according to 1 to 25, characterized in that either one or more related Workpieces with a combined precipitation be occupied. 27. Claim according to 1 to 26, characterized in that the built-up dispersion layer is deposited on a surface which is at a different angle to the actual cutting edge. Can be assigned:

• a) only the outside
• b) only the inside
• c) Inside and outside

28. Claim according to 1 to 27, characterized in that the built-up dispersion layer evenly over the entire tread of the opposite Shaving blades is applied (upper and lower part of the cutters). The moving upper processed part according to claim 27. 29. Claim according to 1 to 28, characterized in that the built-up dispersion layer with an additional covering - either metallic or plastic - is covered. 30. Claim according to 1 to 29, characterized in that the structure of the dispersion layer by an additional treatment can be refined. Either too decorative purposes or to identify the different shapes of cutters or in the Dispersion layer contain grain sizes and Qualities. 31. Claim according to 1 to 20, characterized in that the applied dispersion layer from a Metal alloy matrix with a share of up to 60 vol.% of conductive particles, non-conductive Particles or their combination of a medium Diameter up to 100 microns, preferably from up to to 3 µm.