SEMI-FINISHED PRODUCT, METHOD FOR PRODUCING A SEMI-FINISHED PRODUCT AND USE THEREOF

Abstract

The disclosure relates to a blank-shaped or strip-shaped semi-finished product comprising at least one first metal layer and at least one plastics layer, which are joined over their full area to one another to form a metal/plastic composite. The material thickness of the metal layer being is not more than 1.5 mm. The material thickness of the plastics layer is at least 0.2 mm. A method for producing said product is also provided. One object of the present invention, of providing a semi-finished product which is significantly lighter than the semi-finished products used in the prior art, is achieved for a semi-finished product.

Claims

1-12. (canceled)

13. A blank-shaped or strip-shaped semi-finished product comprising: at least one first metal layer; at least one plastics layer, the at least one first metal layer and the at least one plastic layer being joined over their full area to one another to form a metal/plastic composite; and wherein the material thickness of the metal layer is not more than 1.5 mm and the material thickness of the plastics layer is at least 0.2 mm and wherein a visible surface of the metal layer of the metal/plastic composite has a coil coating.

14. The semi-finished product as claimed in claim 13, wherein the metal layer is formed from a double-side metallically coated steel material.

15. The semi-finished product as claimed in claim 14, wherein the semi-finished product comprises a second metal layer which is joined over its full area to the free surface of the plastics layer to form a metal/plastic/metal composite, the material thickness of the second metal layer being not more than 1.5 mm.

16. The semi-finished product as claimed in claim 15, wherein the visible surface of the second metal layer of the metal/plastic/metal composite has a coil coating.

17. The semi-finished product as claimed in claim 16, wherein a visible surface of at least one of the first and the second metal layer is textured.

18. The semi-finished product as claimed in claim 13, wherein the at least one plastics layer is formed from a temperature-stable plastic which is temperature-stable to at least 200° C.

19. The semi-finished product as claimed in claim 18, wherein the at least one plastics layer is formed from a temperature-stable plastic which is temperature-stable to at least 220° C.

20. The semi-finished product as claimed in claim 17, wherein the plastic is fiber-reinforced, the fibers used being temperature-stable to at least 200° C.

21. The semi-finished product as claimed in claim 20, wherein the plastic is fiber-reinforced, the fibers used being temperature-stable to at least 220° C.

22. A method for producing an at least single-side coated, blank-shaped or strip-shaped semi-finished product, the method comprising: joining at least one first metal layer and at least one plastics layer over their full area to form a metal/plastic composite; wherein the material thickness of the metal layer is not more than 1.5 mm and the material thickness of the plastics layer is at least 0.2 mm; and coating a visible surface of the metal layer of the metal/plastic composite in a coil coating process.

23. The method as claimed in claim 22, further comprising: arranging a second metal layer which is connected over its full area to the free surface of the plastics layer to form a metal/plastic/metal composite, wherein the visible surface of the second metal layer of the metal/plastic/metal composite is coated in a coating process.

24. The method as claimed in claim 23, further comprising baking the plastic such that the temperature stability of the plastic is ensured, a temperature of in particular at most 220°.

25. The method as claimed in claim 23, further comprising baking the plastic such that the temperature stability of the plastic is ensured, a temperature of in particular at most 200°.

26. The method as claimed in claim 24, wherein the visible surface of at least one of the first and second metal layer is textured.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention is elucidated in more detail below by means of a drawing which represents exemplary embodiments. Identical parts are provided with identical reference symbols.

[0018] FIG. 1: shows a cross section through part of a trunk construction for refrigerated transport from the prior art,

[0019] FIG. 2a): shows a section through a first example of an inventive semi-finished product which can be used as a paneling component,

[0020] FIG. 2b): shows a section through a second example of an inventive semi-finished product which can be used as a paneling component, and

[0021] FIG. 3: shows a diagrammatic sequence of steps in a first example of an inventive method.

DETAILED DESCRIPTION

[0022] Depicted in FIG. 1 as an example is a cross section through a part of a trunk construction for refrigerated transport, comprising metal sandwich panels, as is currently implemented in the prior art. The metal sandwich panel 1 has, for example, a first steel panel 2, which is arranged on the outside A and which is provided on both sides of the steel panel 2 with a metallic coating 3, more particularly with a zinc coating. Applied to the outside A on the visible surface of the steel panel 2 is a further coating in the form of a coil coating 4. Disposed on the inside I of the metal sandwich panel 1 is a second steel panel 2′, which is provided on both sides of the steel panel 2′ with a metallic coating 3′, more particularly with a zinc coating, and with a food-resistant organic layer 5, further to the inside I, and which has a material thickness which is the same, for example, as the material thickness of the first steel panel 2. Arranged between the steel panels 2, 2′ is a plastics core 6, as for example a foamed plastic, which completes the metal sandwich panel 1. The material thickness of the steel panels 2, 2′, especially that of the first steel panel 2, is 0.6 mm, for example, and cannot be lowered further in material thickness for stability reasons and because of high loads occurring during travel.

[0023] Depicted as a first embodiment of an inventive semi-finished product in FIG. 2a) is a semi-finished product 7 in the form of a metal/plastic composite. The semifinished product 7 comprises a metal layer 8, preferably of a steel material, which is double-side metallically coated 9, more particularly galvanized, preferably electrolytically galvanized, and which has a material thickness of, for example, 0.3 mm. The preferably double-side electrolytically coated steel material 8 is joined on one side over its full area to a plastics layer 10, which is temperature-stable to at least 200° C., more particularly to at least 220° C., and has a material thickness of, for example, 0.5 mm. On the side opposite the plastics layer, the visible side of the metal layer 8 is provided with a coil coating 11. The semi-finished product 7 of the invention is outstandingly suitable as a component, more particularly as a paneling component for commercial vehicles or trailers. It is true that the material thickness of the semi-finished product 7 is somewhat greater than the material thickness of the steel panel 2, but by reducing the proportion of metal in the inventive semi-finished product 7 it is possible to save mass when it is used, for example, as a paneling component, as part of a trunk construction for refrigeration transport, and the relatively thin metal layer can be readily implemented in combination with a plastics layer, in the form of a metal/plastics composite, by means of coil coating lines (not shown here). Likewise not shown here, the plastics layer may have fiber-reinforcement, which may in turn improve the stiffness and/or strength of the semi-finished product. It may well be the case that, when using fiber-reinforced plastic, a further reduction in the material thickness of the metal layer is possible, depending on application.

[0024] As a second embodiment of an inventive semi-finished product, FIG. 2b) shows a semi-finished product 7′ in the form of a metal/plastic/metal composite. In contrast to the semi-finished product 7, the semi-finished product 7′ has a second metal layer 8′, preferably composed of a steel material, which is double-side metallically coated 9′, more particularly galvanized, preferably electrolytically galvanized, and is joined over its full area to the free surface of the plastics layer 10′. The individual material thicknesses of the semi-finished product 7′ for the first and second metal layers 8, 8′ are, for example, 0.2 mm and, in the case of the plastics layer 10′, 0.3 mm, for example. The advantages stated for the semi-finished product 7 can also be transposed to the semi-finished product 7′.

[0025] Not shown, it is possible, for example, for the visible surface at least of the first metal layer 8 to be textured, in order to impart an improved appearance to the subsequent use of the inventive semi-finished product 7, 7′.

[0026] In FIG. 3 there is a schematic sequence of steps for producing at least single-side coated, blank-shaped or strip-shaped semi-finished products, more particularly in a coil coating line. In step 12, preferably, a strip-shaped coil is provided which comprises either an aforesaid metal/plastic composite, provided on the plastics side preferably with a protective film to protect the plastics surface and in order to avoid sticking to the metal side in the wound state, this film being removed or peeled off subsequently, or comprises a metal/plastic/metal composite, the thickness of the metal layer being not more than 0.5 mm, more particularly not more than 0.4 mm, preferably not more than 0.35 mm, and more preferably not more than 0.3 mm, the metal layer being formed preferably from a steel material and being double-side coated, preferably electrolytically coated, and the thickness of the plastics layer being at least 0.2 mm, more particularly at least 0.3 mm, preferably at least 0.4 mm, and the plastic being temperature-stable to at least 200° C., more particularly to at least 220° C. The strip-shaped coil is unwound and supplied continuously to step 13 for the cleaning of the at least first metal layer. Passivation/activation of the at least first metal layer takes place in step 14, and so subsequently an adhesion promoter (primer) is applied (step 15) to the at least first metal layer by means of an application roll, this primer being baked (step 16) at a temperature which is tailored to the plastic in such a way as to ensure the temperature stability of the plastic in the assembly, the temperature set being more particularly not more than 220°, preferably not more than 200° C. In the next step 17, a coil coating is applied by an application roll to the at least first metal layer which already has the baked adhesion promoter, and this coil coating is baked in turn at a temperature (step 18) which corresponds essentially to the temperature in step 16. In step 19 there is either rewinding to form a strip-shaped semi-finished product, the coil coating being provided with a protective film, or the strip is cut into lengths to form blank-shaped semi-finished products.

[0027] Not shown here, the at least first metal layer may be textured. The texturing may be applied on the one hand as an elevation, in the course of the coil coating process, to the at least first metal layer, in step 18, for example. This can be implemented, for example, by correspondingly machined application rolls. Alternatively or cumulatively, embossments may be shaped, after the coil coating operation or after the baking operation, into the at least first metal layer, by means of an embossing roll after step 19, for example, the embossing force in particular being adapted such that there is no flow or decrease in thickness of the plastics layer in the composite. The material thickness of the metal layer (8, 8′) is at least 0.05 mm, more particularly at least 0.1 mm, and preferably at least 0.15 mm. The material thickness of the plastics layer (10, 10′) is not more than 3.0 mm, more particularly not more than 2.5 mm and preferably not more than 2.0 mm.

[0028] The invention is not confined to the exemplary embodiments shown in the drawing, and instead semi-finished products of the invention can be used in all sectors and may replace existing solutions (coil-coated metal panels) where an important part is played by weight reduction, as in the area of doors, industrial gates, garage doors, etc., for example. The use is not confined to vehicle construction or white goods.

List of Reference Symbols

[0029] 1 metal sandwich panel

[0030] 2, 2′ steel panel

[0031] 3, 3′ metallic coating

[0032] 4 coil coating

[0033] 5 food-resistant organic coating

[0034] 6 plastics core

[0035] 7 metal/plastic composite, semi-finished product

[0036] 7′ metal/plastic/metal composite, semi-finished product

[0037] 8, 8′ metal layer

[0038] 9, 9′ metallic coating

[0039] 10, 10′ plastics layer

[0040] 11 coil coating

[0041] 12 provision of a strip-shaped coil

[0042] 13 cleaning

[0043] 14 activation/passivation

[0044] 15 application of adhesion promoter

[0045] 16 baking of adhesion promoter

[0046] 17 application of coil coating

[0047] 18 baking of coil coating

[0048] 19 rewinding/cutting to length