EP1926861A1

EP1926861A1 - Dimpled sheet and method for producing such a sheet

Info

Publication number: EP1926861A1
Application number: EP06776089A
Authority: EP
Inventors: Jörn SCHRÖER; Heinz Peter Raidt; Jens Odendahl
Original assignee: Ewald Doerken AG
Current assignee: Ewald Doerken AG
Priority date: 2005-09-19
Filing date: 2006-06-28
Publication date: 2008-06-04
Anticipated expiration: 2026-06-28
Also published as: WO2007033712A1; DE102005044800B3; EP1926861B1

Abstract

The invention relates to a dimpled sheet (1), in particular for building purposes and preferably for use as a protective sheet for foundation walls or as a drainage sheet, having a flat region (2) and a plurality of dimples which project over the flat region (2) and which comprise a dimple casing (4) and, if appropriate, a dimple cover (5), and to a method for producing such a dimpled sheet. To make it possible for the dimpled sheet to be produced in a simple and cost-effective manner while ensuring a high degree of loadability, provision is made according to the invention for at least one dimple (3) to be provided in its upper dimple region (8) with a bead projecting over a directly adjacent region and/or for a secondary material to have a yield point which is greater than the yield point of the main raw material in the lower dimple region (9) or in the flat region (2), thereby producing a region with an increased load-bearing capacity.

Description

NOPPENBAHN ÜND PROCESS FOR THE MANUFACTURE OF SUCH A

The invention relates to a dimpled sheet, in particular for building purposes and preferably for use as a foundation wall protection or drainage membrane, with a flat area and a plurality of protruding over the flat area, a knobbed shell and possibly a Noppendeckel having nubs. Furthermore, the present invention relates to methods for producing a dimpled sheet, in particular for construction purposes and preferably for use as a foundation wall protection or drainage, in the deep-drawing process, wherein the dimpled sheet a flat region and a plurality of over the flat area protruding, a knobbed shell and possibly a Having noppendekkel having nubs, wherein the dimpled sheet is made of a deep-drawn film.

Striped membranes of the type mentioned are already known from the prior art. Such dimpled sheets are usually produced by deep drawing. The thermoforming process refers to the so-called thermoforming. For this purpose, a flat film of uniform thickness is first produced. Thereafter, the film is deep-drawn either in still hot and thus plastic state or after prior heating via a tool. In principle, however, it is also possible that deep drawing is not carried out by hot molding but cold.

In the case of dimpled sheets, it is generally crucial to have the highest possible compressive strength of the knobs. The more pressure-resistant the nubs are, the greater the possible installation depth with increasing earth pressure or the load capacity for horizontal laying. The compressive strength of a dimpled sheet is determined by several factors. An essential factor here is first the basis weight of the dimpled sheet. Furthermore, the geometry of the nub affects the load limit. For truncated conical nubs, the flank angle of the truncated cone has just as much influence as the number of pegs per unit area. Another determining factor is the modulus of elasticity of the raw material used. This determines the maximum force on reaching the yield strength of the loaded dimpled sheet and thus its rigidity. However, high stiffness generally suffers from the impact resistance and flexibility of the dimpled sheet and thus the user-friendliness.

In order to achieve an increase in the resilience of the dimpled sheet with existing dimpled geometry and given raw material, so usually a thicker flat film is used. However, this additional use of raw material has a disadvantageous effect on costs.

The object of the present invention is to avoid the aforementioned disadvantages of the prior art.

According to the invention, it is provided in the above-mentioned dimpled sheet that at least one nub in its upper nub region has a bead projecting beyond the immediately adjacent region and / or has a secondary material with a yield strength which is greater than the yield strength of the main raw material in the lower nub region or in the flat region , The nub is thus formed in the invention so that the upper nub area is ultimately designed to absorb higher loads than the lower nub area and thus has an increased load capacity. The invention is based on investigations in connection with the production process. It has been found that fundamentally different wall thicknesses occur in the deep drawing process due to the extraction and stretching of the material. So far, efforts had been made to achieve a uniform distribution of the wall thickness in the dimpled sheath. It was considered that if the thickness distribution is uneven, the zone of the smallest thickness determines the load capacity. Experiments have shown that the knob bulges at a corresponding load when the material over a large area, the yield strength is exceeded. It has been found that geometric changes while maintaining the wall thickness bring no advantage. This is how z. B. knobs with ribbing of the lateral surface or training as polygonal truncated pyramid no different than pure truncated cones. Investigations in connection with the invention have now shown that the completely uniform thickness distribution in the dimpled casing is not the most favorable. For example, if a truncated cone-shaped knob is loaded, the highest occur Strains in the upper region of the lateral surface. In contrast, the lid surface and the foot area experience only reduced tension. This stress distribution also results in nubs that have a different geometry than the truncated cone.

With regard to the above-mentioned test results, it is provided in an alternative according to the invention that, in order to achieve a high loading capacity or carrying capacity with little use of material, it is only necessary to correspondingly reinforce the upper knobbly area with a bead protruding beyond the immediately adjacent areas to provide an increased compressive strength, while the lower knobbly area and / or the flat area do not require such training. Accordingly, the dimpled sheet according to the invention can be produced in part without additional use of material as known dimpled sheets and thus without higher manufacturing costs, with a significantly increased load capacity is given. Thus, the increased load capacity in the upper knob area can be achieved, for example, by distributing the raw material mass in the nub so that the greatest concentration is present in the region of the highest load. In the case of this alternative according to the invention, this is achieved in that the region of increased load-bearing capacity is thickened or provided with the bead in relation to the lower nub area. The thickening or the bead should preferably be formed circumferentially as annular bead. In this context, it should be noted that the ring shape ultimately refers to a circumferential shape, regardless of whether the ring is round, oval, polygonal or has another shape. Basically, the ring must not be closed. The ring may be composed of individual ring segments which need not necessarily be connected together.

In the second alternative according to the invention it is provided that in the region of increased carrying capacity, a secondary material is provided with a yield strength which is greater than the yield strength of the main raw material in the lower nub area and / or in the flat area. Usually, the higher yield strength is associated with a raw material having a higher modulus of elasticity and / or a higher transverse contraction number. In this embodiment, it is even possible in principle to have a constant wall Thickness to use, and yet to achieve an increase in the load capacity or carrying capacity.

In a further alternative according to the invention, it is provided that in the aforementioned dimpled sheet a multilayer thermoforming sheet with at least one layer with a first material and a layer with a second material is provided as starting material. Due to the multi-layered nature of the thermoforming sheet, the dimpled sheet produced therefrom is correspondingly multi-layered. In this case, the material of the first layer has a greater melt viscosity than the material of the second layer. The aforementioned melt viscosity influences the flow behavior of the material of the individual layers. Materials with high melt viscosity have poorer flow, so flow less than materials with a lower melt viscosity. As a result of these different melt viscosities results in thermoforming a dimpled sheet with knobs, the material with the higher melt viscosity during deep drawing process more in the upper part of the knob remains, that is drawn less than the material with the lower melt viscosity. In this way, the two layers in the dimpled casing are of different conical conformation. The layer thickness of the first material is much larger in the upper region of the nub than the layer thickness of the second material in the upper region. In the end, this results in a greater conicity of the first layer in the upper nub area compared to the second layer.

It is particularly advantageous in this connection that the material of the first layer, ie with the higher melt viscosity, at the same time has a higher yield strength than the material of the second layer. The result in this embodiment is a dimpled sheet, in which the knobs have an extraordinarily high load-bearing capacity, since the higher-viscous material with increased yield strength has a very high layer thickness in the nub and in particular in the upper nub area, while the layer thickness of the nubs first layer in the lower nub region and in particular in the flat region is reduced compared to the layer thickness of the second layer. Overall, the dimpled sheet thus retains a relatively high degree of flexibility and thus good handleability. In particular, it has been found in connection with the present invention that the highest stresses occur in the upper half and in particular in the upper third of the lateral surface, in particular the annular region at the transition from Noppendeckel to Noppenmantel and in particular below the upper end of the dimpled shell and so that it is highly loaded below the transition from Noppendeckel to Noppenmantel. Accordingly, it is provided in the invention that the area of increased load capacity in the upper third and in particular in a ring area at the transition or below the transition from Noppenmantel to Noppendeckel is provided so that this area for receiving higher loads than the lower knob area and the flat area is trained.

The annular region, which preferably begins shortly below the transition from the nub shell to the nub cover, preferably has a width which corresponds at least to approximately one eighth of the height of the nub. Preferably, the width of the annular region is between one-sixth and one-third of the height of the dimpled shell.

When the dimpled sheet is made by deep-drawing, it is usually such that the conversion thickness of the dimple in the dimpled casing to the upper end, i. towards the Noppendeckel increases. In this case, a wedge-like or even approximately conical shape is achieved. In other manufacturing methods, a continuous or permanent conversion thickness can in principle also be achieved. In the context of the present invention, however, it is independent of the manufacturing process so that the bead as a local increase or thickening of the immediately adjacent area, which adjoins, for example, down to the bead lifts. Ultimately, this local projection is independent of whether the wall thickness of the nub shell is constant or increases substantially continuously in the direction of the nub cover.

In a further alternative according to the invention is to increase the

Carrying capacity of the dimpled sheet provided that in the starting flat film specifically a certain orientation of the polymer chains used

Plastic is selected to increase the yield strength in the nubs. He- According to the invention, it is provided in this connection that the main direction of orientation of the polymer chains extends at least in regions in the longitudinal direction of the dimpled shell. It is preferred in this context that the aforementioned alignment of the polymer chains is provided on opposite sides of the dimpled shell. By the aforementioned alignment of the polymer chains in the longitudinal direction of the dimpled shell an increased force absorption is possible.

The main direction of the orientation of the polymer chains of the starting film and thus the preorientation of the polymer chains can be achieved, for example, by vigorous extraction of the still molten film in the production or stretching of the film in the solid state (stretching), preferably monoaxially but also biaxially. In the case of monoaxial stretching, however, ultimately only one main direction of the polymer chains is achieved, so that an increased force absorption or carrying capacity of the drawn nub results only on opposite sides in the main direction of the polymer chains. In order to achieve not only a partial reinforcement of the nub in this context, it is advisable that the starting flat film has a plurality of precursors whose polymer chains are correspondingly preoriented. In this case, the individual flat films should then be offset from one another from the main direction of the preorientation. For two films, an offset of about 90 ° should be given, while for example when using three films, an offset of about 60 ° to each other is given.

For a larger number of films, the monoaxially stretched films are preferably to be arranged such that the individual main directions are at least substantially at the same angle to each other. Instead of using a plurality of monoaxially stretched prefilms, it is basically also possible to use one or more biaxially oriented prefilms. Here then the arrangement in certain angular positions of the Vorfolien is not essential.

In addition to increasing the carrying capacity, another significant advantage of using a dimpled sheet with preoriented polymer chains is that a material with a relatively high compressive strength can be achieved in a comparatively simple manner, which otherwise would only be achieved by an increased th material use, ie can achieve a thicker starting film. The idea of the invention of preorientation is therefore not limited to use in dimpled sheets, but also for other applications in which starting films are used, transferable.

Various production processes are suitable for producing the dimpled sheet according to the invention. In a first embodiment, in the production of the deep-drawing film, the primary raw material of the thermoforming film is selectively or partially added with secondary raw material having a yield strength which is increased in comparison with the main raw material. The main raw material and the secondary raw material are therefore different materials. The secondary raw material is added to those zones where nubs are deep-drawn and form the upper nub area after deep drawing and in particular the ring area in the upper third of the nub at or below the transition from Noppenmantel to Noppendeckel. In this embodiment, therefore, the raw material with increased yield strength is added in a very targeted manner at the points of maximum load capacity, in order to achieve an increase in the load capacity. In contrast, the remainder of the dimpled sheet, i. H. The lower nub area and also the flat area, made only from the main raw material, so that there is a high flexibility of the material and thus a user-friendliness in this area. Preferably, the addition of the secondary raw material takes place in the calendering process. The addition of the secondary raw material to the main raw material ultimately results in a mixture of the two materials and thus a material inhomogeneity. For manufacturing reasons, it is difficult to provide only the secondary raw material in the area of increased load-bearing capacity. However, the mixture of the main raw material and the secondary raw material leads to an increase in the yield strength in this area. In order to avoid too much bleeding of the secondary material in this area and in order to achieve a further reinforcement, it may offer that in addition to the secondary raw material a fibrous or fleece-like material is provided in the region of increased carrying capacity, beyond the function met a flow barrier.

In the second alternative of the production method according to the invention, it is provided that, for the production of the thermoforming film, an initial Flat film substantially constant thickness regions thickenings are applied, and that the thickenings are applied to those zones or areas where pimples are deep-drawn and after deep drawing the upper nub area and in particular a Ringbe- rich in the upper third of the nub at or below form the transition from Noppenmantel to Noppendeckel.

The third alternative differs from the previous one in that, after deep-drawing the thermoforming sheet, thickenings are applied to the upper nub area and in particular to the ring area in the upper third of the nub at or below the transition from the nub coat to the nub top. In the case of both abovementioned alternatives, it is ultimately possible to additionally supply material in the melt stage, which is preferably applied annularly before or after the deep-drawing process. This can be done by placing and welding of annular discs as well as by supplying melt from annular nozzles.

In principle, it is also possible to produce the points or thickenings at the desired zones without supplying additional melt before the deep-drawing process. For this purpose, it is provided in the fourth alternative of the manufacturing method according to the invention that for the production of thermoforming a starting flat film substantially constant thickness is calendered such that areawise thickenings result by accumulation of mass, and that the thickenings are generated at such zones where at Deep drawing process is the largest shell thickness to arise, namely in particular in the ring area in the upper third of the knob at or below the transition from Noppenmantel to Noppendeckel.

In the case of the fifth production alternative according to the invention, it is ultimately provided that a layer having a plurality of individual layer regions is preferably applied to the still flat starting film in the printing process, the layer regions ultimately being provided on the zones of maximum stress. The layer regions preferably each have a ring shape. The material of the layer or the layer regions is chosen such that the heat transfer to the mold during deep drawing is influenced. Thus, an increase in the heat transfer leads to the layer range to a faster cooling. This in turn means that the film is tougher in these areas and thus less take off.

Moreover, it goes without saying that, as an alternative to the aforementioned fifth alternative, it is fundamentally also possible to provide a layer with a different material, namely precisely in the regions which are not subject to any increased stress. In this case, the layer then prevents faster cooling. Ultimately, this is then the "negative alternative" to the fifth alternative method.

Another way to create thick spots or thickenings is to cool the zones concerned before the deformation begins. For this purpose, the sixth alternative method provides that for the production of thermoforming a starting flat film of constant thickness is partially cooled and that those zones are cooled, where nubs are deep-drawn and after deep drawing the upper nub area and in particular the ring area in the upper third of the nub form at or below the transition from the dimpled shell to the Noppendeckel. As a result, the zones which are colder by a few degrees of temperature become less plastic and less mass is drawn off from these zones during the deep-drawing process than from the other warmer areas. The cooling of the respective zones can z. B. by blowing with air. The air can be directed through a mask on the zones to be cooled. Another possibility is to direct the air with a variety of individual nozzles on the zones.

The basic idea of the sixth production alternative is to achieve temperature differences between individual regions of the thermoforming film. This idea also underlies the seventh procedural alternative. The necessary temperature differences are generated by the fact that the temperature is raised in the zones of the knob, which are to be pulled down later. These are ultimately the zones that form the lower nub area after deep drawing. This can be done with heated air, which is concentrated via a mask or individual nozzles on the desired zones. The increase in temperature can also be done with heat radiators. Another possibility to concentrate raw material mass in the region of the highest load of the nub, provides the eighth embodiment of the method according to the invention. In this process, web material is displaced from the lower nub area and / or the nub cover into the upper nub area and in particular into the ring area in the upper third of the nub at or below the transition to the nub coat from the nub coat to the nub cover during thermoforming. This is preferably done in the last phase of the deep-drawing process, while the deformed plastic mass is sufficiently plastic. The displacement in the area in question is generated via a predetermined shape of the thermoforming tool. Thus, for example, a positive upper and lower punches can be used during deep drawing in order to concentrate mass in the upper third of the outer and / or the inner jacket zone.

In the ninth alternative method is provided that after deep drawing web material is displaced from the Noppendeckel to the outside, so that at the transition from Noppenmantel Noppendeckel an annular bead results, so that at this point a higher degree of stress can be absorbed. This method can be realized, on the one hand, when the deep-drawn dimpled sheet is still in the lower die of the deep-drawing mold, namely in that a stamp displaces the material out of the area of the nub cover to the outside. In the other alternative, a mold separate from the thermoforming mold is used with the upper and lower dies, the nub being positively seated on the lower die and the upper punch being used to displace melt from the lid region.

To produce a dimpled sheet with a preorientation of the polymer chains, it is provided in a further alternative method that the starting flat film is pre-oriented in terms of its polymer chains by vigorous extraction of the still molten film during production and / or stretching of the film in the solid state. If the starting flat film has several prefilms, these are correspondingly preoriented, with the main orientation of the polymer chains of the individual prefilms then being offset from one another. In a further method alternative according to the invention, a multilayer film with at least one first and one second layer is used as the deep-drawing film. In this case, the material of the first layer has a higher melt viscosity than the material of the second layer. As a result of these material properties results after deep drawing a nub in which the upper layer of the nub, the material of the first layer is more concentrated, since this is less fluid than the second material, which is less concentrated in the upper region. In contrast, the more flowable material of the second layer is more concentrated in the lower nub area and in the flat area because of its lower melt viscosity. Ultimately, this results in a very viable in the field of knobs, flat but very flexible dimpled sheet.

It should be pointed out, moreover, that in all methods of rotation, in which an increased load-bearing capacity during deep-drawing is produced, it is fundamentally also possible to achieve the increased load capacity in the upper area by means of appropriate measures only after deep-drawing. Thus, for example, a bead or a material reinforcement in the upper knobbly area can also be produced by subsequent application or attachment of material.

Incidentally, it is understood that the foregoing and subsequent range not only includes the respective specified start and end values but also all within the interval limits values, even if these values are not specified in detail.

Hereinafter, a conventional dimpled sheet, but otherwise different Noppenbahnen invention, which are prepared by different methods of the invention, shown in detail and described. It shows

1 shows schematically a region of a dimpled sheet in plan view,

2 is a plan view of a thermoforming sheet after calendering for producing a dimpled sheet according to the invention, 3 is a cross-sectional view of a nub in two embodiments of a prior art dimpled sheet having a uniform wall thickness;

Fig. 4 is a cross-sectional view of a knob of an inventive

Dimpled sheet,

5 shows a schematic cross-sectional view of a nub of a dimpled sheet according to the invention, wherein a material thickening is produced by cooling,

6 shows a cross-sectional view of a nub of a dimpled sheet according to the invention during deep drawing, wherein a material thickening is produced by displacement,

7 is a view corresponding to FIG. 6 of another embodiment,

8 shows a cross-sectional view of a nub of a dimpled sheet according to the invention, wherein the thickening of the material takes place by displacement by means of a separate molding tool,

9 is a cross-sectional view of a thermoforming sheet for a dimpled sheet according to the invention and

10 shows a cross-sectional view of a nub of a dimpled sheet according to the invention, which has been produced from the thermoforming sheet according to FIG. 9.

In Fig. 1, a part of a dimpled sheet 1 is shown, which is intended for use as a foundation wall protection or drainage. The dimpled sheet 1 has a flat region 2, which preferably has a substantially constant wall thickness. Furthermore, the dimpled sheet 1 has a multiplicity of studs 3 projecting beyond the flat region 2. The number of nubs per unit area may vary. Usually, more than 50 nubs per m ^{2 are} provided, whereby basically every value of more than 50 nubs pen / m ^{2 is} possible. Preferred embodiments are between 1,000 and 10,000 nubs / m ² . Each of the nubs 3 has a knobbed shell 4 and an upper Noppendeckel 5. The height of the knob is usually greater than 2 mm. As a rule, the nub height is between 3 and 20 mm, in the present case it is about 5 mm. With a 5 mm high nub the diameter is usually 6 mm while the diameter of the base is about 8.5 mm. The flank angle is 14 °. However, it is understood that the aforementioned geometry is only one embodiment. Although the nubs shown 3 are frusto-conical, it is understood that the nubs 3 can basically have any geometry. In addition to the frustoconical design, the knobs can, for example, truncated pyramidal, round, polygonal, ribbed u. Like. Be formed. The dimpled sheet 1 itself otherwise consists of a plastic material of small wall thickness, which has been produced by deep-drawing.

It is not shown, moreover, that the nubs 3 of the dimpled sheet a water-permeable layer, for example in the form of a drainage fleece or the like. can be applied.

Incidentally, it should be noted that, although not shown, the nub 3 does not necessarily have to have a nub-lid. In principle, it is possible that an opening adjoins the nub shell 4 at the top, the nub cover 5 thus eliminated. Moreover, it is so that the Noppendeckel 5 and / or the flat area 2 need not have a closed surface. Also, a ridge or lattice-like design, i. with through holes, is readily possible.

In Fig. 2 is a thermoforming sheet 6, from which the dimpled sheet 1 shown in Fig. 1 is produced, shown. The deep-drawing film 6 itself has been produced from a starting flat film, not shown, of substantially constant thickness. In detail, the thermoforming sheet 6 at preferably all points at which later nubs 3 are formed by deep drawing, annular thickening 7, which have been produced by calendering.

FIG. 3 shows part of a dimpled sheet 1 belonging to the prior art, which has a flat region 2 and a multiplicity of nubs 3. has. Each nub 3 has a knobbed jacket 4 and a Noppendeckel 5. It is shown in the left-hand illustration of FIG. 3 that the dimpled casing has a substantially conically tapered thickness or material thickness, while in the right-hand representation a uniform wall thickness or material thickness of the dimpled shell 4 is provided. Moreover, it is pointed out that these are only schematic representations. The left-hand part of the nub shown in FIG. 3 is a nub 3 produced by deep drawing, wherein the deep drawing results in the wall thickness decreasing from top to bottom. The embodiment shown in the right-hand part of FIG. 3 has an essentially constant wall thickness. This knob has been produced by another manufacturing method.

The nubs 3 shown in the following FIGS. 4 to 8 correspond in shape to that in the right part of the knob 3 shown in FIG. 3. However, it will be understood that the nubs shown in FIGS. 4 to 8 also correspond to the wall thickness of FIG in the left part of the nub shown in Fig. 3, although not shown.

FIG. 4 shows part of a dimpled sheet 1 according to the invention. The representation according to FIG. 4 corresponds to the illustration according to FIG. 3, the decisive difference being that the nub 3 has an increased load capacity in its upper nub area 8 in relation to the lower nub area 9. The upper nub area 8 extends over the upper third of the nub 3, while the lower nub area 9 constitutes the middle third and the lower third including the Noppenfußes. In the embodiment shown in FIG. 4, the upper nub region 8 and specifically a circumferential annular region 10 at or below the transition from the nub shell 4 to the nub cover 5 is designed as an area of increased load-bearing capacity, so that higher loads can be absorbed in this region. This is realized in the embodiment shown in Fig. 4, characterized in that in this area a secondary raw material is provided with a yield strength which is greater than the yield strength of the main raw material in the lower nub area 9 or in the flat area 2 or Noppendeckel 5. Although it is possible in principle would be the secondary raw material with the higher yield strength also partially or completely in the It is on the one hand more cost-effective to provide the secondary raw material only in the ring area 9 of the nub 3, both in terms of strength and cost. Incidentally, in the embodiment shown in Fig. 4, both the ring portion 10 and the remaining portions of the nub 3 and also the flat portion have a constant wall thickness, though not necessarily required.

Furthermore, the longitudinal direction L of the dimpled shell 4 is shown by way of example in FIG. 4. To increase the carrying capacity of the knob 3 is presently the example of the imple mentation form shown in FIG. 4, provided that the polymer chains of the plastic of the dimpled sheet 1 extend from its main direction forth in the longitudinal direction L of the dimpled shell. It should be noted that this embodiment can be provided with preoriented polymer chains in principle, in the embodiment of FIG. 4, however, must not be provided.

FIGS. 5 to 7 each show knobs 3 of dimpled sheets 1, the area of increased compressive strength and, in particular, the annular area 10 being thickened relative to the lower knobbly area 9 in each case. The thickening is in each case formed as a circumferential annular bead 1 1. In the embodiments of FIGS. 5 and 6, in each case an outer annular bead 11 is provided, while in the imple mentation form of FIG. 7, an inner annular bead 11 is provided. In the embodiment according to FIG. 8, the annular bead is provided as a projecting area following the knob cover 5.

Hereinafter, various alternatives for producing a dimpled sheet 1 are shown based on the individual representations.

As has already been mentioned, the dimpled sheet 1 is produced from a thermoforming sheet 6 by deep-drawing, wherein deep-drawing takes place in the thermoforming process, although a cold thermoforming is possible. The production of the dimpled sheet 1 shown in FIG. 4 takes place in such a way that, in the production of the corresponding starting flat film or in the case of the laminating method, the main raw material in the loading area of the secondary raw material added with the higher yield strength. The loading region designates the annular region 10 at the transition from the studded jacket 4 to the nub cover 5. The deep-drawing film 6 produced in this way is subsequently deep-drawn using a conventional thermoforming tool to form a dimpled sheet 1 according to FIG.

The thermoforming sheet 6 shown in FIG. 2 already has thick points or thickenings 7 produced by calendering prior to the thermoforming process, in which case mass is accumulated annularly on the loading area by embossing. Subsequently, the thermoforming sheet 6 can be deep-drawn according to FIG. 2 in a conventional deep-drawing tool to a dimpled sheet 1.

In Fig. 5, a method is shown schematically, wherein the thermoforming sheet 6 is cooled before deep drawing in the load area. The cooling takes place via an air flow 12, wherein the supplied air is selectively supplied through a mask 13 to the load area. By cooling in the load area results in a reduction in plasticity, and it is deducted less mass during the thermoforming process from this zone than from the warmer areas. 5, the point of the maximum thickness of the annular bead 1 is 1 to an upper third of the upper nub area 8, but well below the Noppendeckels. 5

In the embodiment shown in FIGS. 6 and 7, the annular bead 11 is produced in the last phase of the deep-drawing operation, while the deformed plastics material is sufficiently plastic, with the deep-drawing tool, namely the upper punch 14 and the lower punch 15. In this case, melt is displaced from the lower nub area 8 and / or the Noppendeckel 5 in the upper nub area 8. In the embodiment according to FIG. 6, the lower punch 15 is conical, while the upper punch 14 corresponds at least substantially to the negative shape of the lower punch 15. However, a peripheral recess 16 is provided in the upper region of the upper punch 14, which constitutes the receiving or collecting space for the displaced material and allows the production of the annular bead 11. Moreover, it is understood that instead of the illustrated embodiment according to FIG. 6 it is also possible to provide on at least one of the end regions 17, 18 of the upper punch 14 and / or the lower punch 15 a planar projection to material from the central region of the Noppendek - Kels 5 outward in the direction of the annular bead 1 1 to displace.

The embodiment according to FIG. 7 differs from the embodiment according to FIG. 6 only in that the recess 16 is provided on the lower punch 15 and not on the upper punch 14. This results in an inner annular bead 11th

In Fig. 8 it is shown that a mold with an upper punch 19 and a lower punch 20 is used to displace melt or material from the Noppendeckel 5 to the outside, so that an outer circumferential annular bead 11 in the load area, ie in Transition from the lid to the side wall surface results.

FIG. 9 shows a deep-drawing film 6 which has two layers and has a first layer 25 and a second layer 26. Both layers have the same layer thickness in the initial state, but this is not necessarily required. Both the one and the other layer can basically be thicker. The material of the first layer 25 has a greater melt viscosity and, in the present case, also a greater yield strength than the material of the second layer 26.

FIG. 10 shows a part of a dimpled sheet 1 deep-drawn from the deep-drawing film according to FIG. 9. A nub 3 of the dimpled sheet 1 is shown in FIG. Due to the different material properties and in particular the different melt viscosity results in deep drawing a different flow behavior of the material of the first layer 25 and the second layer 26. The high melt viscosity of the material of the first layer 25 causes a comparatively large in the nubeck Layer thickness is present, which decreases in the area of the knobbed shell 4 with a relatively large taper downwards. In contrast, the taper in the material of the second layer 26 is considerably lower. The material thickness decreases less conical. In the flat region 2, the material thickness of the second layer 26 is greater than that of the first layer 25.

Claims

claims:

1. dimpled sheet (1), in particular for building purposes and preferably for use as Grundmauerschutz- or Dränbahn, with a flat area (2) and a plurality of over the flat area (2) protruding, a knobbed jacket (4) and possibly a Noppendeckel (5 ) having nubs (3), characterized in that at least one nub (3) has in its upper nub area (8) over a directly adjacent region protruding bead and / or a secondary material having a yield strength which is greater than the yield strength of Hauptrohstoffs in the lower nip area (9) or in the flat area (2), so that there is an area with increased capacity.

2. dimpled sheet (1), in particular for building purposes and preferably for use as Grundmauerschutz- or Dränbahn, with a flat area (2) and a plurality of over the flat area (2) projecting, a knobbed shell (4) and possibly a Noppendeckel (5 ), characterized in that the dimpled sheet (1) is multi-layered with at least a first layer (25) and at least a second layer (26) such that the material of the first layer (25) has a greater melt viscosity than the material the second layer (26) and that the layer thickness of the first layer (25) in the upper nub region (8) is greater than the layer thickness of the second layer in this region.

3. dimpled sheet according to claim 2, characterized in that the material of the first layer (25) has a greater yield strength than the material of the second layer (26).

4. dimpled sheet according to one of the preceding claims, characterized in that the region of increased load capacity in the upper Half, preferably in the upper third of the knob (3) and in particular below the upper end of the knobbed shell (4) is provided.

5. dimpled sheet according to one of the preceding claims, character- ized in that the region of increased carrying capacity is annular in an annular region (10) on the dimpled casing (4) is formed.

6. dimpled sheet according to one of the preceding claims, characterized in that the width of the annular region (10) at least one-eighth of the height of the nub (2) corresponds, preferably between one-sixth and one-third of the height of the nub (3).

7. dimpled sheet according to any one of the preceding claims, characterized in that the secondary material with the higher yield strength solely borrowed in the annular region (10) of the knob (3) is provided.

8. dimpled sheet according to one of the preceding claims, characterized in that the bead is designed as a circumferential annular bead (11).

9. dimpled sheet according to any one of the preceding claims, characterized in that the wall thickness of the dimpled shell (4) is constant or in the direction of the knob cover (5) increases substantially continuously.

10. dimpled sheet (1), in particular for building purposes and preferably for use as a foundation wall protection or drainage, with a flat area (2) and a plurality of over the flat area (2) protruding, a knobbed shell (4) and possibly a Noppendeckel (5 ), in particular according to one of the preceding claims, wherein the stud web (1) is produced from a starting flat film, and the starting flat film consists of a polymer chain comprising plastic, characterized in that the main direction the orientation of the polymer chains extends at least on two opposite sides of the knobbed jacket (4) in the longitudinal direction (L) of the studded jacket (4).

11. dimpled sheet (1) according to claim 10, characterized in that the starting flat film has a plurality of Vorfolien and that, preferably, the main direction of the polymer chains of a prefilm is offset from the main direction of the polymer chains of a further prefilm.

12. A method for producing a dimpled sheet (1), in particular for building, in the deep-drawing process, wherein the dimpled sheet (1) a flat region (2) and a plurality of over the flat region (2) protruding, a dimpled shell (4) and possibly one Noppendeckel (5) having nubs (3), wherein the dimpled sheet (1) from a thermoforming sheet (6) is produced, characterized in that for producing the thermoforming sheet (6) the main raw material of the starting flat film partially secondary raw material with one opposite added to the main raw material yield strength and that the secondary raw material is added to those zones where nubs (3) are deep drawn and after deep drawing the upper nub area (8) and in particular a ring portion (1 1) in the upper third of the nub (3 ) at or below the transition from the dimpled shell (4) to the Noppendeckel (5).

13. The method according to claim 12, characterized in that the addition of the secondary raw material takes place by calendering.

14. A method for producing a dimpled sheet (1), in particular for building, in the deep-drawing process, wherein the dimpled sheet (1) a flat region (2) and a plurality of over the flat region (2) protruding, a dimpled shell (4) and optionally having a Noppendeckel (5) having nubs (3), wherein the dimpled sheet (1) is made of a thermoforming sheet (6), characterized in that applied to produce a thermoforming sheet (6) on a starting flat sheet substantially constant thickness thickening area and that the Verdik- kung be applied to such zones where nubs (3) are deep-drawn and after deep drawing the upper nub area (8) and in particular a ring portion (10) in the upper third of the nub (3) at or below the transition from the dimpled shell (4) to the Noppendeckel (5).

15. A method for producing a dimpled sheet (1), in particular for construction purposes, by thermoforming, wherein the dimpled sheet (1) a flat portion (2) and a plurality of over the flat portion (2) protruding, a knobbed jacket (4) and optionally a Noppendeckel (5)

5 send nubs (3), wherein the dimpled sheet (1) from a thermoforming sheet (6) is produced, characterized in that after thermoforming of the thermoforming sheet (6) thickening on the upper nub area (8) and in particular on the ring portion (10 ) in the upper third of the nub (3) at or below the transition from the nub sheath (4) to the nub cover (5).

16. The method according to claim 14 or 15, characterized in that the application of the thickenings by supplying melt in particular from nozzles, preferably annular nozzles, or by fastening, preferably

15 welding, of discs, in particular of annular discs, takes place.

17. A method for producing a dimpled sheet (1), in particular for building, in the deep-drawing process, wherein the dimpled sheet (1) a flat portion (2) and a plurality of over the flat area (2) protruding, one NEN Noppenmantel (4) and optionally having a nub cap (5) having nubs (3), wherein the dimpled sheet (1) from a thermoforming sheet (6) is produced, characterized in that for producing the thermoforming sheet (6) an output flat sheet substantially constant thickness is calendered in such a way in that thickenings (7) are produced in areas by collection of mass, and that the thickenings (7) are produced at zones where nubs (3) are deep-drawn and after deep-drawing the upper nub areas (8) and in particular, form a ring region (10) in the upper third of the nub (3) at or below the transition from the nub sheath (4) to the nub cover (5). 0

18. A method for producing a dimpled sheet (1), in particular for building, in the deep-drawing process, wherein the dimpled sheet (1) a flat portion (2) and a plurality of over the flat portion (2) protruding, a knobbed jacket (4) and optionally a Noppendeckel (5) aufwei- 5 send nubs (3), wherein the dimpled sheet (1) is made of a thermoforming sheet (6), characterized in that for the production of Thermoforming film (6) is applied to a starting flat film of constant thickness, a layer having a plurality of layer areas, that the layer areas are provided at such zones where nubs (3) are deep drawn and after deep drawing the upper nub area (8) and In particular, a ring region (10) in the upper third of the nub (3) at or below the transition from the nubbed shell (4) to Noppendeckel (5) form and that the layer areas influence the heat transfer to the mold during deep drawing in such a way that in the Layer areas give a faster cooling than in other areas.

19. The method according to claim 18, characterized in that the layer is applied in the printing process on the output flat film.

20. A method for producing a dimpled sheet (1), in particular for construction purposes, by thermoforming, wherein the dimpled sheet (1) a flat region (2) and a plurality of over the flat region (2) projecting, a dimpled shell (4) and optionally having a Noppendeckel (5) having nubs (3), wherein the dimpled sheet (1) from a thermoforming sheet (6) is produced, characterized in that for producing the thermoforming sheet (6) a starting flat film of substantially constant thickness is partially cooled and that such zones are cooled, where nubs (3) are deep drawn and after deep drawing the upper nub area (8) and in particular a ring portion (10) in the upper third of the nub (3) at or below transition from the nub shell (4) Make Noppendeckel (5).

21. The method according to claim 20, characterized in that the cooling of the zones takes place by blowing with air and that, preferably, the air supply to the zones to be cooled via a mask (13) or via a plurality of individual nozzles.

22. A method for producing a dimpled sheet (1), in particular for building, in the deep-drawing process, wherein the dimpled sheet (1) a flat region (2) and a plurality of over the flat region (2) protruding, a Noppenmantel (4) and optionally a nub (5) having nubs (3), wherein the dimpled sheet (1) from a thermoforming He (6) is produced, characterized in that for producing the thermoforming sheet (6) a starting flat film of substantially constant thickness is partially heated and only those zones are heated, forming the deep nip area (9) after deep drawing.

23. The method according to claim 22, characterized in that the heating of the zones by heat radiators or blowing with heated air takes place, wherein, preferably, the air supply to the zones to be heated via a mask (13) or via a plurality of individual nozzles.

24. A method for producing a dimpled sheet (1), in particular for building, in the deep-drawing process, wherein the dimpled sheet (1) a flat portion (2) and a plurality of over the flat portion (2) protruding, a knobbed jacket (4) and optionally a Noppendeckel (5) has protruding nubs (3), wherein the dimpled sheet (1) is produced from a thermoforming sheet (6) of substantially constant thickness, characterized in that during thermoforming sheet material from the lower nub area (9) and / or the Noppendeckel (5) in the upper nub region (8) and in particular in the annular region (10) in the upper third of the nub (3) is displaced at or below the transition from the nubbed shell (4) to the Noppendeckel (5).

25. The method according to claim 24, characterized in that the web material in an outer and / or an inner annular bead (1 1) is displaced.

26. A method for producing a dimpled sheet (1), in particular for building, in the deep-drawing process, wherein the dimpled sheet (1) a flat portion (2) and a plurality of over the flat portion (2) protruding, a knobbed jacket (4) and optionally a Noppendeckel (5) has protruding studs (3), wherein the studded membrane (1) is produced from a thermoforming foil (6) of essentially constant thickness, characterized in that after thermoforming, web material is displaced out of the nub hood (5) to the outside, so that at or below the transition from the dimpled shell (4) to the Noppendeckel (5) results in a torus (11).

27. The method according to claim 26, characterized in that the displacement takes place via a punch, while the dimpled sheet (1) is still on the lower punch (15) of the deep-drawing mold, or that the displacement outside the thermoforming mold via a forming tool with upper punch (19 ) and lower punch (20) takes place.

28. A method for producing a dimpled sheet (1), in particular for building, in the deep drawing method, wherein the dimpled sheet (1) a flat region (2) and a plurality of over the flat region (2) projecting, a Noppenmantel (4) and possibly ., a knob (5) having nubs (3), wherein the dimpled sheet (1) is made of a thermoforming sheet (6), characterized in that for the preparation of the thermoforming sheet (6) treated a starting flat film of a plastic polymer chains such is that there is a preorientation of the orientation of the polymer chains and that from the pre-oriented thermoforming sheet, the dimpled sheet (1) is deep-drawn.

29. The method according to claim 28, characterized in that the preorientation is achieved by removing the still molten starting film during the production and / or stretching of the film in the solid state.

30. The method of claim 28 or 29, characterized in that the thermoforming sheet has a plurality of preoriented Vorfolien, wherein the main direction of the preorientation of the individual Vorfolien offset zueinan- is.

31. A method for producing a dimpled sheet (1), in particular for building, in the deep-drawing process, wherein the dimpled sheet (1) a flat region (2) and a plurality of over the flat region (2) protruding, a Noppenmantel (4) and possibly a nub (5) having nubs (3), wherein the dimpled sheet (1) is made of a thermoforming sheet (6), characterized in that the thermoforming sheet (6) is multi-layered and at least a first layer (25) and a second Layer (26) and that the material of the first layer (25) has a greater melting viscosity than the material of the second layer (26).