DE102018111762A1 - Process for coating cutting knives - Google Patents

Abstract

The invention relates to a method for coating cutting knives, in particular sickle or circular knives, for machines for slicing food products, preferably high-performance slicer, in which at least one in contact with the food products in contact surface area with a coating, in particular a non-stick coating , the method comprising the following step: - forming local elevations by applying a pattern of a plurality of discretely distributed amounts of material.

Description

The present invention relates to a method for coating cutting knives, in particular sickle or circular knives, for machines for slicing food products, preferably high-performance slicers, in which at least one surface area coming into contact with the food products during operation is coated with a coating, in particular a non-stick Coating is provided.

Furthermore, the invention relates to a cutting blade, in particular sickle or circular blade, for machines for slicing food products, preferably high-performance slicer, in which at least one, preferably in operation coming into contact with the food products, surface area is provided with a coating, in particular with a non-stick coating.

In various fields of technology carrier materials are provided with coatings. In particular, so-called non-stick coatings are provided in many areas of technology for certain carrier materials, which prevent the respective products to be processed from adhering to the carrier materials.

Typical applications of such non-stick coatings are, for example, cutting knives in devices for slicing food products, such as e.g. Meat, sausage, ham, cheese or the like. Such cutting knives may e.g. be designed as a rotating circular blade or as a rotating and planetary in addition to another axis rotating circular blade.

The slicing device can be, for example, a high-performance slicer.

It has been shown in cutting blades of the type mentioned that, depending on how the contact between the knife and a separated product disc, the product disc due to the rotating movement of the cutting blade and the adhesion of the product disc on the cutting blade experiences a more or less strong acceleration. Due to this acceleration, it may happen that the product disc is not deposited in a place provided for storing the product disc.

Controlled depositing of disks, in particular in a specific arrangement or, for example, in the form of folded disks, is made more difficult.

Known cutting blades are provided to reduce friction with a non-stick coating. In practice, however, it has been found that for various applications, especially when slicing sensitive products, the provision of a conventional non-stick coating is not sufficient to reduce the acceleration caused by the cutting blade on the separated product slices so that a product slice with the desired accuracy can be stored at the designated location.

It is therefore the object of the invention to provide a method for coating cutting blades, with which the non-stick properties of the knife can be improved.

This object is achieved by a method for coating cutting knives having the features of claim 1.

The method according to the invention comprises the following step: - Forming local elevations by applying a pattern from a plurality of discretely distributed amounts of material.

Investigations have shown that the acceleration experienced by a product disc through the cutting blade, and thus also the deviation from a target deposit location, depends on many factors. A role is played by parameters derived from the product to be sliced, e.g. its dimensions, consistency, temperature and / or composition. The thickness of the separated product slice and the geometry of the cutting knife determine the deviation mentioned above.

It has been found that for all situations occurring in practice, the friction between the surface of the cutting blade and the product slices can be reduced by the elevations formed in the manner according to the invention such that the product slices receive no or only such a slight acceleration that they can be deposited with sufficiently high accuracy exactly at the intended location, for example on a removal belt of a slicer. This is attributed to the coarser surface structure compared to the prior art.

Within the meaning of the invention, the term "local elevation" is to be understood to mean something which, on the one hand-unlike a merely roughened surface-has a sufficient size to be recognized by the naked eye, but which on the other hand does not form an essential part of the invention Knife surface occupies. A mere roughening of a knife surface, for example, would therefore not be covered by the invention. Likewise For example, a few, for example, less than 10 or 20, each relatively large elevations, taken together take a relatively large proportion, such as more than half of the surface area of the knife in question, do not fall under the invention.

The protuberances may according to the invention e.g. on the entire outside of the knife, which shows in the transport direction in the product storage direction, are formed. Alternatively, however, the elevations can also be formed only on one or more subregions of this surface. A partial area is in particular a surface area in contact with the separated product slices. The coating may alternatively or additionally be provided in those areas which serve to generate airflow to support the disc tray. In addition, the coating according to the invention can also be provided on the side facing the product to be sliced, in order to reduce the friction and the tendency for deposits.

A particular advantage of the invention is that the coating can be produced in a particularly simple manner and relatively inexpensively. In particular, it is possible to produce an excellent non-stick coating without expensive specialty materials and without expensive equipment. This will be discussed in more detail elsewhere.

Advantageous developments of the invention are also specified in the dependent claims, the description and the drawings.

According to one embodiment, a sheet of material is applied, wherein either the layer of material is applied prior to application of the pattern as a base layer or after application of the pattern as a cover layer.

The discretely distributed amounts of material forming the pattern may cooperate with the sheet of material to form the bumps.

According to one embodiment, the pattern is applied before the material layer is completely dried, or the material layer is applied before the pattern is completely dried.

The drying of the pattern or the material layer before applying the respective other layer has the advantage that the materials on the one hand do not completely flow together, on the other hand enter into an intimate connection with each other. The emergence of a three-dimensional structure formed by the local surveys is thus ensured. Another advantage of this concept of intermediate drying - that is, drying but not complete drying - is that smooth transitions between the protuberances occur by themselves, regardless of whether the pattern is applied to the material layer or the material layer is applied to the pattern ,

According to a further embodiment it can be provided that an unstructured pattern is applied and / or that the material quantities forming the pattern are distributed unevenly.

Alternatively it can be provided that a structured pattern is formed and / or that the material quantities forming the pattern are distributed uniformly.

The pattern can be applied by sprinkling, flaking or spraying the amounts of material. Special techniques or complex devices are not required to apply the pattern. For example, a conventional paint spray gun can be used.

Depending on the application technique used, the pattern may be due to a random distribution of material quantities. Alternatively, the distribution of material quantities can be specified exactly. For this purpose, in particular according to a further embodiment of the invention, the pattern can be applied using a mask, a perforated plate or a grid.

As the material for the layer and / or as the material for the pattern, a liquid or powdery substance may be used. In particular, a paint can be used. The material for the layer and the material for the pattern may be identical. But you can also use different materials. For example, the materials may differ in color. If the pattern is applied to a base coat and no additional topcoat is applied, a different design pattern can provide an additional design effect.

The invention is not limited to the provision of a single sheet of material in conjunction with the material forming the pattern. According to another possible embodiment, it is provided that a further planar material layer is applied, which is applied either in the case of an already existing base layer and after the application of the pattern as a cover layer or before the application of the pattern and the cover layer as a base layer.

Due to the additional cover layer, a better homogenization of the surface can be achieved. In addition, the cover layer is a closed layer of material on the surface of the knife, which is advantageous from a hygiene point of view. In addition, in this way the appearance of the knife can be improved. However, these advantages of a cover layer are also given if no base layer is present. Then the amounts of material forming the elevations are in direct contact with the knife surface. The "three-layered" structure of base layer, pattern and cover layer provided in the embodiment discussed here has the advantage of a closed cover layer with optimum adhesion of the individual amounts of material to the base layer. However, the additional material layer increases the effort in the production of the coating according to the invention and also leads to a greater total thickness of the coating.

In the cutting blade according to the invention, the coating comprises a pattern of a plurality of discretely distributed, the surveys forming material quantities.

The coating additionally preferably comprises at least one planar material layer, the pattern being located either below or on the material layer.

The amounts of material may be in the form of speckles, drops, spots, spots or spots.

Furthermore, it is preferably provided that between the material quantities and the material layer in each case a transition region is present in which the materials have merged into each other, are mixed together and / or have penetrated each other. As a result, the individual amounts of material are firmly connected to the material layer. Such a composite can be achieved in particular by the above-described, according to a preferred embodiment of the method according to the invention concept of intermediate drying.

As regards possible dimensions of the quantities of material and / or elevations, it is preferably provided that the diameter of at least a predominant number of material quantities and / or elevations in each case between a lower limit in the range of about 0.05 and 0.10 mm and an upper limit in the range of about 1 to 2mm.

In particular, the diameters of the smallest amounts of material and / or elevations are each in the range of about 0.07 to 0.09 mm and the largest amounts of material and / or elevations each in the range of 1.2 to 2.0 mm. However, this does not exclude that some amounts of material and / or elevations may be smaller or larger than the aforementioned ranges. Individual quantities of material and / or elevations may, for example, have diameters of up to 4 mm.

As far as the occupancy of the relevant surface area with the quantities of material and / or elevations is concerned, it is preferably provided that the proportion of the area of the surface area provided with the coating is 5 to 50%, in particular 15 to 35%, occupied by the quantities of material and / or elevations. is. In particular, this - also referred to as Flächenbestückung - share in the range of 20 to 30%.

The relevant surface area is that area of the surface of the knife on which the material quantities are actually discretely distributed. If not the entire side of a knife is coated according to the invention, but e.g. only in one of the cutting edge of the knife outgoing, annular portion provided with a coating according to the invention, while an inner portion of the relevant side of the knife has no coating according to the invention, this inner portion is not taken into account in the determination of the area equipment.

In particular, the quantities of material or elevations can be dimensioned such that the knife surface is given a freckled appearance in terms of size and distribution of the quantities of material or elevations.

The maximum height of at least a predominant number of material quantities and / or elevations relative to the knife surface or to a material layer underlying the material quantities and / or elevations may be more than 0.3 mm, preferably more than 0.5 mm and particularly preferably more than 1 mm ,

Furthermore, it is preferred if the material for the layer and / or the material for the pattern comprises a liquid or powdery substance, in particular a lacquer.

According to an independent aspect of the invention, which may also be combined with the embodiments disclosed herein, a so-called texture lacquer may be used, which after complete drying itself forms a three-dimensional structure with a plurality of elevations and depressions. Such a structure is also coarser than a roughened surface only. With such a coating, which is also referred to as a hammered finish, a so-called Orange peel or hammer blow effect can be achieved. For example, such a structured lacquer can simply be applied to the knife with a foam roller.

According to a further independent aspect of the invention, which can also be combined with other aspects and embodiments disclosed herein, depressions can be incorporated mechanically into a coating applied to the knife, for example into a coating according to the invention. These depressions may e.g. be produced by grinding, laser cutting, milling or embossing.

It has also been found that knife surfaces formed according to these independent aspects have excellent non-stick properties, in particular with regard to sliced food products.

• 1 eine Draufsicht auf eine Ausführungsform eines erfindungsgemäßen Sichelmessers mit einer ein unstrukturiertes Muster aufweisenden Beschichtung,
• 2 eine Draufsicht auf eine Ausführungsform eines erfindungsgemäßen Sichelmessers mit einer ein strukturiertes Muster aufweisenden Beschichtung,
• 3 eine Draufsicht auf eine Ausführungsform eines erfindungsgemäßen Kreismessers, dessen eine Seite nur teilweise mit einer ein strukturiertes Muster aufweisenden Beschichtung versehen ist, und
• 4 bis 6 in unterschiedlicher Weise gemäß der Erfindung beschichtete Schneidmesser jeweils in einer teilgeschnittenen Seitenansicht.

The invention will now be described by way of example with reference to the drawings. Show it:

• 1 a top view of an embodiment of a sickle blade according to the invention with an unstructured pattern having coating
• 2 a top view of an embodiment of a sickle blade according to the invention with a structured pattern having a coating,
• 3 a plan view of an embodiment of a circular knife according to the invention, one side of which is provided only partially with a structured pattern having a coating, and
• 4 to 6 in different ways according to the invention coated cutting blades each in a partially sectioned side view.

The in the 1 to 3 respectively schematically illustrated cutting blade according to the invention 10 each comprise a steel blade body with a receiving opening 11 for attachment to a high performance slicer and with a spiral ( 1 and 2 ) or circular ( 3 ) Cutting edge 26 ,

The cutting knife 10 are each on the outside, also referred to as the front side, which faces away from the product to be sliced in the cutting operation and thus shows in the storage direction of the product slices to be separated, with a coating according to the invention 14 Provided. With the two sickle blades 10 according to 1 and 2 is the coating 14 provided on the entire outside. The circular blade according to 3 is only in one of the cutting edge 26 outgoing, annular portion of the outside in the manner according to the invention with a coating 14 Provided. An inner portion of the outside of the knife, which does not come into contact with the separated product slices, has no coating according to the invention.

The backs of the knives, not shown 10 may also be provided - wholly or partially - with a coating according to the invention.

The coatings 14 Here, in each case comprise a paint layer applied as a base layer to the knife body 16 to which a variety of discretely distributed amounts of material 19 are applied, each one a survey 18 on the base coat 16 form. These material quantities 19 are also formed by a paint.

In the embodiment of 1 are the surveys 18 randomly distributed on the knife surface, so form an unstructured pattern of surveys 18 , Also in terms of shape and size vary the surveys 18 fortuitously.

Such a pattern with randomly distributed elevations 18 For example, by sprinkling or dribbling the paint on the base layer 16 be generated.

Details pertaining to the preparation of the coating according to the invention will be discussed in more detail below.

Unlike the knife 10 according to 1 is with the knife 10 according to 2 a structured pattern of surveys 18 intended. The at least substantially the same shape and size surveys 18 are on the base layer 16 not randomly distributed, but lie on each parallel to the cutting edge 26 running lines. Such a distribution of surveys 18 For example, it can be made using a mask or template, for example in the form of a pinhole or a grid.

In the regular pattern of the circular knife 10 according to 3 are the surveys 18 arranged at the intersections of a regular grid forming, each intersecting at a right angle lines. Also, this pattern can be generated using, for example, a correspondingly designed pinhole or stencil.

If the the surveys 18 forming material quantities 19 on a previously applied base layer 16 be applied and no additional topcoat is applied over it, then the surveys 18 directly from the material quantities 19 self-educated. Alternatively, regardless of whether a base layer is present on the knife body or not, a covering layer covering the discretely distributed quantities of material can be applied. The thickness of this cover layer is chosen so that the three-dimensional structure is maintained and thus the elevations are each formed by one of the material quantities and the overlying part of the cover layer.

Various possibilities for producing a coating according to the invention 14 show the 4 to 6 ,

According to 4 is like in the embodiments of 1 . 2 and 3 only a single, continuous, continuous material layer is present, namely the base layer applied directly to the knife body 16 , On this base layer 16 are the individual material quantities 19 , each directly one of the surveys 18 form. For example, by means of the previously explained concept of intermediate drying, it is achieved that the quantities of material 19 each gently in an adjacent amount of material 19 or in the surrounding ground layer 16 go over, creating smooth transitions 22 arise.

5 shows the already mentioned, somewhat reverse arrangement, in which the amounts of material 19 each applied directly to the knife body and then with a common continuous cover layer 16 be coated. Again, the already mentioned concept of intermediate drying is used, creating intimate connections between the material of the cover layer 16 and the individual material quantities 19 result. Again, there are between the individual surveys 18 , each of a quantity of material 19 and the overlying part of the cover layer 16 be formed, gentle transitions 22 available.

In the embodiment of 6 are the two variants according to 4 and 5 sort of combined with each other. On a base layer applied directly to the knife body 16 First, a pattern of discretely distributed amounts of material 19 applied. Subsequently, a continuous cover layer 16 applied.

According to a possible procedure, in which a coating 14 according to 4 is prepared in a first step, a base coat is applied to the knife body and then the knife for a period of about 5 minutes at a temperature of 100 ° C superficially dried. Subsequently, using a conventional paint gun, a paint is dripped at a comparatively low pressure in the range of 0.2 to 0.5 bar on the previously applied, only superficially dried basecoat. This second step can be done in a so-called cloister process, in which only the paint spray gun is moved horizontally relative to the blade surface and then vertically back and forth. This process, ie horizontal flaking and subsequent vertical flitting - can be repeated, for example, three times. This results in a pattern of randomly distributed paint drops on the base coat, which has not yet been completely dried. To ensure that the number of drops of paint per unit area over the entire surface in a predetermined range of values, the painter leading the spray gun can compare the resulting paint pattern with a template showing a desired pattern, ie make a visual inspection. If necessary, then further amounts of paint are trickled until the specification is met.

Once this process is completed, the knife is completely dried for a period of about 10 minutes at a temperature of about 380 ° C. The lacquer droplets and the base lacquer, which in each case have merged into one another to a certain extent or have mixed with one another, enter into a binding that is strong in this final drying process. At the same time, as a result of the fact that the paints have run into one another to a certain extent, gentle transitions between the paint drops and the respective base coat are automatically achieved.

Consequently, in this concept of intermediate drying, the lacquer layer applied first is purposefully only dried to such an extent that this base lacquer and the subsequently applied lacquer droplets co-operate in exactly the desired degree, ie. neither converge completely nor just lie on top of each other.

Depending on the properties of the materials used in each case and the size of the amounts of material applied to the base layer in each case, the abovementioned parameters can be varied in particular for the period of time and the temperature of the intermediate drying.

Experiments have shown that with a coating according to the invention or a coating produced by the process according to the invention, in particular the non-stick properties of a cutting knife for food products can be significantly improved, in particular in comparison to cutting blades, which have a conventional paint, which at best with a Surface roughness has been provided.

Cutting knives according to the invention show an excellent cutting behavior. It can be smooth cuts perform that lead in particular to no scoring in the cut surfaces. The cutting blades of the invention produce no or at most a negligible abrasion of the products. In addition, the separated product slices can be stored exactly due to the low friction in the respectively predetermined manner.

Furthermore, it has been shown that the coated in the manner according to the invention cutting blades are particularly resistant to contamination and can be cleaned very well. Also, a high mechanical strength of the knife is given, so that long service life is guaranteed.

It has also been found that, at least for certain products, it is possible to dispense with soiling of the products which has hitherto been carried out prior to slicing, ie. With the cutting blades according to the invention also less dimensionally stable products can be easily cut without additional measures.

Another advantage of the invention is that the coating can be applied in a simple manner and using inexpensive materials. In particular, conventional paints or varnishes can be used. Furthermore, no special tools or expensive devices for applying the coating are required. In particular, it has been found that a person familiar with the handling of a conventional paint spray gun masters the application of the discretely distributed quantities of material in a short time. With a lot of effort or time to acquire special skills are therefore not required for the preparation of the coating according to the invention.

LIST OF REFERENCE NUMBERS

10

cutting blade

11

receiving opening

14

coating

16

material layer

18

survey

19

amount of material

22

crossing

26

cutting edge

Claims (17)

Method for coating cutting knives (10), in particular sickle or circular knives, for machines for slicing food products, preferably high-performance slicers, in which at least one surface area coming into contact with the food products during operation comprises a coating (14), in particular a non-stick Coating, the method comprising the following step: - Forming local surveys (18) by applying a pattern of a plurality of discretely distributed amounts of material (19). Method according to Claim 1 characterized in that at least one sheet of material (16) is applied, wherein either the layer of material (16) is applied prior to application of the pattern as a base layer or after application of the pattern as a cover layer. Method according to Claim 2 , characterized in that the pattern is applied before the material layer (16) is completely dried, or that the material layer (16) is applied before the pattern is completely dried. Method according to one of the preceding claims, characterized in that an unstructured pattern is applied and / or that the material quantities forming the pattern (19) are distributed unevenly. Method according to one of Claims 1 to 3 , characterized in that a structured pattern is formed and / or that the material quantities forming the pattern (19) are evenly distributed. Method according to one of the preceding claims, characterized in that the pattern is applied by spraying, flaking or spraying the amounts of material (19). Method according to one of the preceding claims, characterized in that the pattern is applied using a mask, a perforated plate or a grid. Method according to one of the preceding claims, characterized in that a liquid or powdery substance is used as material for the layer (16) and / or as material for the pattern, in particular a lacquer. Method according to one of Claims 2 to 8th , characterized in that a further sheet-like material layer (16) is applied, which is applied either with an existing base layer and after applying the pattern as a cover layer or before applying the pattern and the cover layer as a base layer. Cutting knife (10), in particular sickle or circular knife, for machines for slicing food products, preferably high-performance slicer, in which at least one, preferably in operation coming into contact with the food products, surface area is provided with a coating (14), in particular one A non-stick coating, wherein the coating (14) is obtained or obtainable by a method according to any one of the preceding claims. Cutting knife (10), in particular sickle or circular knife, for machines for slicing food products, preferably high-performance slicer, in which at least one, preferably in operation coming into contact with the food products, surface area is provided with a coating (14), in particular one A non-stick coating comprising a plurality of local protuberances (18), the coating (14) comprising a pattern of a plurality of discretely distributed amounts of material (19) forming the protuberances (18). Cutting knife (10) after Claim 10 or 11 , characterized in that the coating (14) additionally comprises at least one planar material layer (16), wherein the pattern is located either below or on the material layer (16). Cutting knife (10) after one of Claims 10 to 12 , characterized in that the amounts of material (19) are provided in the form of speckles, drops, spots, spots or speckles. Cutting knife (10) after Claim 12 or 13 , characterized in that between the amounts of material (19) and the material layer (16) in each case a transition region is present, in which the materials have merged into each other, run into each other, are mixed together and / or have penetrated each other. Cutting knife (10) after one of Claims 10 to 14 , characterized in that the diameter of at least a majority of the quantities of material (19) and / or elevations (18) is in each case between a lower limit in the range of about 0.05 and 0.10 mm and an upper limit in the range of about 1 to 2 mm. Cutting knife (10) after one of Claims 10 to 15 , characterized in that the proportion of the area of the surface area provided with the coating (14) by the quantities of material (19) and / or elevations (18) amounts to 5 to 50%, in particular 15 to 35%. Cutting knife (10) after one of Claims 10 to 16 , characterized in that the material for the layer (16) and / or the material for the pattern comprises a liquid or powdery substance, in particular a lacquer.

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