Creping blade design

Abstract

The invention relates to a creping blade (1) with a blade-like main part (8) made of metal, in particular steel or stainless steel, said main part having a working edge (2) which can be placed against a drying cylinder (3) and which adjoins an end face (4) with a counter-edge (5). Grooves (6) are worked into the end face (4) and are arranged at a distance to one another, and a wear protection layer (7) is provided on the wall of the main part (9) between the working edge (2) and the main part (8), wherein the grooves (6) are worked at least into the wear protection layer (7).

Description

[0001] The invention relates to a crepe scraper with a blade-shaped base body made of metal, in particular steel or stainless steel, which has a working edge that can be applied to a drying cylinder, to which an end face with a counter edge is attached, wherein notches are incorporated into the end face and arranged at intervals from each other, according to the features of the preamble of claim 1.

[0002] A crepe scraper of this type is known from EP 1 157 818 A1. This crepe scraper has notches incorporated into its end face, spaced apart from one another. The notches are intended to improve the scraper's performance. However, a disadvantage is the considerable wear on the working edge, as the crepe scraper, and especially its working edge, is not wear-resistant.

[0003] The invention is based on the objective of improving a generic crepe scraper in such a way as to avoid the described disadvantages.

[0004] This problem of the invention is solved by the features of claim 1.

[0005] According to the invention, a wear-resistant layer is provided on the wall of the base body between the working edge and the base body, and the notches, which can also be described as recesses, grooves, interruptions, or the like, are incorporated at least in the wear-resistant layer. This creates a wear-resistant working edge while retaining the advantages of the notches or grooves. The notches can be produced by embossing using a knurling tool. However, they can also be produced, particularly in the area of ​​the wear-resistant layer, by grinding, especially pulsed grinding.

[0006] The depth of the grooves is preferably about 200 µm, with the width of the grooves preferably being about 350 µm. Advantageously, the wear-resistant layer is preferably about 30 µm thick. These geometric specifications can vary individually, in combination, or all together by + / - 5%, optionally by + / - 10%, and further optionally by + / - 20%, depending on the application and geometric size of the crepe scraper.

[0007] It is advantageous if the width (d) of the notches at the working edge is less than 1 relative to their spacing (I). This implies that the spacing between the notches is greater than their width. The depth (ht) of the notches at the working edge relative to their width (d) is less than 1, which means that the depth of the notches is relatively small compared to their width.

[0008] In a further embodiment of the invention, it is proposed that the notches between the working edge and the opposing edge have a uniform cross-section, i.e., are groove-like. However, the notches can also extend from the working edge towards the opposing edge. In this case, it is advantageous that the length (hf) of the notches relative to their maximum depth (ht) is less than 5. This means that the length of the notches is considerably greater than their depth.

[0009] In a further development of the invention, it is proposed that the wear-resistant layer be multilayered and comprise a ceramic coating, a coating made of a mixture of oxide ceramics, and a ceramic-metal coating. These coatings are designed, in particular, to exhibit both basic hardness and high wear resistance.

[0010] Although a crepe scraper is known from DE 10 2011 115 813 A1, on whose working edge / side wall several ceramic layers are applied, these are straight at the working edge, i.e. without interruptions or notches.

[0011] An embodiment of the invention is shown in simplified form in the drawings.

[0012] They show: Figure 1: a sketched side view of a crepe scraper and a drying cylinder, Figure 2: a section through a crepe scraper in the area of ​​the working edge on an enlarged scale, Figure 3: a partial section through a crepe scraper, Figure 4: a partial section through the crepe scraper according to circle Y in Figure 3 Figure 5: a section through a crepe scraper and Figure 6: a partial view of the crepe scraper according to the circle in Figure 5 .

[0013] In the Figures 1 to 6As detailed below, 1 is a crepe scraper which is in working contact with a drying cylinder 3 by means of a working edge 2. The crepe scraper 1 has an end face 4 extending from the working edge 2 to a counter edge 5. On the end face 4, as shown in Figure 1 As shown in the sketch, notches 6 are incorporated. The crepe scraper 1 also has a wear-resistant layer 7 on the side facing the drying cylinder 3, which forms the working edge 2 in the area of ​​the end face 4. The notches 6 are incorporated both in a base body 8 of the crepe scraper 1 and in the wear-resistant layer 7.

[0014] How in particular Figure 2As can be seen, the partial surface of the base body 8 below the wear-resistant layer 7, which extends to the end face 4, is designed as a chamfer, with the chamfer angle being a maximum of 25°. The notches 6 can be angular with an approximately rectangular cross-section, round corresponding to a semicircular cross-section, wedge-shaped, or the like.

[0015] The base body 8 of the crepe scraper 1 is made of steel or stainless steel and can be ground with the edge, whereby the end face 4 is also ground at an angle or oblique to the longitudinal plane of the crepe scraper 1. The notches 6 in the area of ​​the end face 4 can be produced, particularly in the area of ​​the base body 8, by embossing. The notches 6 are produced in the area of ​​the wear-resistant layer 7, preferably by grinding or pulsed grinding.

[0016] In the cut of Figure 4 and the view of Figure 6The width of the notches 6, the spacing between the notches 6, and the depth of the notches 6 are denoted by d, I, and ht, respectively. The notches 6 according to Figure 6 are tapering in depth, with their length being denoted by hf.

[0017] The ceramic coating preferably consists of titanium oxide, aluminum oxide, chromium oxide, zirconium oxide, and the like. A mixture of oxide ceramics, chromium oxide / zirconium oxide, is particularly proposed. For the ceramic-metal (cermet) coatings, WC or Cr3C2 are particularly suitable. Reference symbol list

[0018] 1 Crepe scraper 2 Working edge 3 Drying cylinder 4 End face 5 Counter edge 6 Notches 7 Wear protection layer 8 Base body b Notch width I Notch spacing h Notch depth hf Notch length

Claims

1. Creping doctor (1) comprising a blade-like main body (8) composed of metal, in particular composed of steel or stainless steel, having a working edge (2) which can be placed against a drying cylinder (3) and which is adjoined by an end face (4) with a counterpart edge (5), wherein notches (6) are incorporated into the end face (4) and are arranged at distances from one another, characterized in that a wear protection layer (7) is provided between the working edge (2) and that wall of the main body (8) which faces towards the drying cylinder (3), in that the wear protection layer (7) forms the working edge (2) in the region of the end face (4), and in that the notches (6) are incorporated into both the main body (8) and the wear protection layer (7).

2. Creping doctor (1) according to Claim 1, characterized in that the width (d) of the notches (6) at the working edge (2) in relation to the distance (1) between them is smaller than 1.

3. Creping doctor (1) according to either of Claims 1 and 2, characterized in that the depth (ht) of the notches (6) at the working edge (2) in relation to the width (d) of the notches (6) is smaller than 1.

4. Creping doctor (1) according to one of Claims 1 to 3, characterized in that the notches (6) have the same cross section continuously between the working edge (2) and the counterpart edge (5).

5. Creping doctor (1) according to one of Claims 1 to 3, wherein, proceeding from the working edge (2), the notches (6) end in the direction of the counterpart edge (5), characterized in that the length (hf) of the notches (6) in relation to their maximum depth (ht) is smaller than 5.

6. Creping doctor (1) according to Claim 1, characterized in that the wear protection layer (7) is of multi-layer embodiment and comprises a ceramic coating, a coating composed of a mixture of oxidic ceramics and a ceramic-metal coating.

Images