COMPOSITE SLAB WITH A WITH BURLS PROVIDED MIDDLE CLASS, PREFERABLY FROM PLASTIC AND PROCEDURE FOR THEIR PRODUCTION

The invention concerns a composite slab in accordance with the generic term of the requirement 1 as well as a procedure for their production in accordance with requirement 12.

It is already a composite slab admits become, which exhibits a middle class with on one side formed out burls, whereby on both sides of the middle class one smooth external layer each is up-covered. On the one side the up-covered external layer with front surfaces of on one side formed out burls is located in connection. On the opposite side by the Aufkaschieren of the external layer on a ground of the middle class, from which the burls extend, sealed Luftkammern are trained.

This composite slab exhibits the disadvantage that on one side formed out burls extend over the entire height of the middle class and exhibit in particular due to a negative figuration the ground of the burls a small wall thickness. Also in the transient area from the ground to the cylindrical lateral surface of the burls a particularly thin wall thickness is given due to the vacuum deformation in the female form. This leads to the weakening of the composite slab. On the opposite side of the composite slab conditions turned around exactly. The external layer forms a reinforcement with the ground of the middle class with exception of the cavities formed by the burls. Thus this composite slab exhibits the disadvantage that this composite slab can take up differently strong loads to dependence of the installation position. Beyond that the plastic film up-covered on the front surface of the burls can tear off easily, since the tapered wall thicknesses of the ground of the burls and directly the range of the lateral surface adjacent on it due to the negative figuration mostly cannot take up the loads. The moreover this composite slab exhibits the disadvantage that a deformation or an adjustment at certain geometry is very reduced possible after heating the composite slab. On the one hand therefore, since on the one side, on which the ground of the middle class is connected with the external layer of the plastic plate, substantially higher heating temperatures are necessary, than on the opposite side, in order to heat the composite slab for deformation. The moreover the ranges of the external layer, which are not strengthened by the ground of the middle class due to the formation of the burls, are too strongly heated, so that these ranges of the external layer can bump out or break open.

Beyond that this composite slab exhibits the disadvantage that due to the manufacturing process between the individual layers of the composite slab high internal voltages are present. In particular due to the different Wärmeaufnahmen on the one side, on that the external layer at the ground of the middle class lies close and to the opposite external layer, which is up-covered only on the front surfaces of the burls, results from the different linear extensions internal voltages, which forgave the plastic plate supported.

From the DE 295 03 254 U1 is a further plastic plate admits become, which is intended for packing containers. This composite slab exhibits, approximately according to the principle of the cardboard, a cavity structure with two lidding foils on both sides. This composite slab exhibits the disadvantage that the break rigidity is very small transverse to the lengthwise-running waveform-shaping the cardboard and thus the employment of such composite slabs is very strongly reduced.

The invention is therefore the basis the task to create a composite slab which exhibits a high inherent rigidity and small internal voltages and in deforming to different geometry to adapt as well as fast and simply is to be manufactured.

This task is solved by a composite slab in accordance with the characteristics of the requirement 1.

This composite slab makes possible that by those reciprocally an even material distribution for the burls is given to one center level formed out burls, so that during the deformation of the middle class for the training of the burls following the material from the connecting sections developing between the burls can take place into the formed out burls. Thus both the wall thickness of the ground of the burl and the lateral surface, in particular in the transient area as the ground, can be clearly improved and strengthened trained. The moreover this composite slab exhibits the advantage that the contact area is to that or the up-covered layers on each side equal to the middle class.

In particular it is intended that on each side of the middle class at least a layer is arranged. Thus this composite slab exhibits independently the installation position or direction a continuous inherent rigidity and maximum stress. By those reciprocally one center level formed out burls the ductility of the composite slab is increased clearly. This composite slab is trained without inclusion of air cushions and exhibits beyond that on both sides the same conditions regarding the contact area between the front surface of the burl and the up-covered layer, so that on both sides an even heating up and a following deformation can take place.

After a favourable arrangement of the invention it is intended that the middle class before-strained exhibits positively and negatively formed burls to the center level. Thus production of a homogeneous and stable middle class can take place in economical way, with which those are positively and negatively formed burl of almost same or same quality. The terms positively and negatively mean different collection directions to the centre plane. By the Vorrecken, which takes place in particular symmetrically to the centre plane, a middle class with burls is created, which are made after the positive reforming procedure quasi exclusively of formed burls.

After a further favourable arrangement of the invention it is intended that those are symmetrically to each other trained positively and negatively formed burls of the middle class. Thus a delay of the composite slab, consisting of at least three layers, is to a very large extent dezimiert. The internal voltages are reduced, whereby the load-carrying capacity and also inherent rigidity of the composite slab are increased.

After a further favourable arrangement of the invention it is intended that the distance of the center level to the front surfaces of the positive and negative burls is trained directly. Thus the symmetry in the structure of the composite slab of the moreover is increased. The connecting sections trained between that positively and negatively formed burls at least partly lie in the center level, which represents the neutral fiber of the composite slab at the same time. Thus the flexural rigidity of the composite slab is independently alike to the installation direction.

Alternatively to this arrangement it can be intended that for example the negatively formed burl is trained in the height smaller according to amount than the positively formed burl. Alternatively it can be also intended that conditions are exchanged regarding the height that positively and negatively formed out burl. In dependence of the application the situation of the center level can be arbitrarily arranged between that at least two layers arranged at the middle class.

After a further favourable arrangement of the invention it is intended that those are positively and negatively formed burls in regular intervals line and spaltenförmig to each other arranged, whereby - along a line or a column seen - which are to each other intended positively and negatively formed burls alternating. Thus an even arrangement can be given by positive and negative burls, which increases the rigidity of the composite slab beyond that after the Aufkaschieren of the layers to both sides of the middle class. By this symmetry also simplified cutting is made possible for the composite slab on certain measures. In dependence of the cut line a certain sectional view can be selected. The moreover the number of burls can be substantially increased by this arrangement, whereby the connecting surface between the front surfaces of the burls and the up-covered layers is increased. The moreover both on the one side and on the other side of the center level of the middle class according to amount the same surface is to the Aufkaschieren of the layers intended.

After a further favourable arrangement of the invention it is intended that the front surface of the burls is small trained in relation to the distance area between two positively or negatively formed burls. Thus it is made possible that both the lateral surface of the burls and the ground of the burls exhibit a sufficient wall thickness after the positive and female forms, whereby the stability of the composite slab can be increased.

After a further favourable arrangement of the invention is intended that those are arranged positively and negatively formed burls together-bordering and exhibit a transient area, which itself straight-lined between the front surfaces that positively and negatively extends formed burl. Thus a rigid connection between the two front surfaces is given, which makes a high force admission possible in particular during a square grid and/or arrangement of the burls in lines and columns.

After a further favourable arrangement of the invention it is intended that between the transient areas connecting sections are trained, which are intended in the range of the center level. Thus a symmetrical structure of the composite slab can take place. These connecting sections go favourable-prove flowing into the transient area and into the lateral surface and into the ground of the burls over. Alternative it is intended, in particular with continuous production of the middle class by a rolling or a pair of volumes that the connecting sections approximate to a level extending in two dimensions itself. Thus quasi two separate chambers are formed within the layers of the composite slab, which make possible also an execution of different media, for example to cooling, heating, dams or the like.

After a further favourable arrangement of the invention it is intended that the burls are kegelstumpfförmig trained. Thus particularly flowing transitions can be trained. The moreover also a suitable Luftzirkulation between the up-covered layers can be made possible. Alternatively can be intended just as pyramidenstumpfförmige, halfspherical burls with a flattening, mehreckförmige burls with flattening or other geometry for the training of the burls.

This composite slab is manufactured according to invention by a procedure in accordance with requirement 12. This procedure exhibits the advantage that a composite slab is producible, which smaller internal voltages admitted in relation to from the conditions the technology plate exhibit. The moreover the Aufkaschieren of the layers on both sides of the middle class is relieved, since the front surfaces of the burls with the layers are to be only welded.

Favourable way is intended that the layers in the laminating station are applied at the same time on both sides of the middle class. Thus the composite slab can be finished in a laminating station. Beyond that the same spannings arise at both sides of the middle class, which become balanced by Vorrecken of the middle class.

After a further favourable arrangement of the invention it is intended that the production of the middle class and the Aufkaschieren of the layers on both sides of the middle class are continuously accomplished. Thus a high throughput and a high productivity for the production of the composite slab can be given.

Further favourable arrangements of the procedure are indicated in the further requirements.

On the basis the following description and the designs a preferential remark example of a composite slab and a procedure for its production are more near described. Show

Figure 1

a perspective opinion of a composite slab,

Figure 2

a plan view on a middle class of the composite slab,

Figure 3

a schematic sectional view of a middle class along the line III III in figure 2,

Figure 4

a schematic sectional view of a composite slab along a line IV-IV in figure 2 of the middle class and

Figure 5

a schematic representation from process steps to the production of the composite slab according to invention.

In figure 1 a composite slab 11 is perspectively represented. This composite slab 11 exhibits a middle class 12, which reciprocally by a layer 13 and 14 is surrounded. A such composite slab 11 is for example completely made of plastic. Here can be used for example HDPE, PE or PP, HP, ABS or such as plastic. Such composite slabs are used for example in the automotive engineering for ground, side and roof linings and covered if necessary with additional layers. Beyond that the composite slab can be used as cavity lining, partition or cover, for re-usable packagings as putting or folding box and for packing for machines and apparatus parts; likewise as reinforcement and insertion hurry, light weight suit-case, materials for the building sector or such a thing. In dependence of cases of application the plastic is selected. Likewise adapted to it the wall thicknesses of the layers 13 and 14 and the middle class 12 as well as their entire dimensioning are selected.

After a further execution form of the composite slab is intended to apply a middle class and on one of the two sides of the burls one or more layers. The composite slab can be used for applications, whose maximum stress is smaller and/or adaptability more largely than with the composite slab in accordance with the figures 1 and 4 necessary.

In the figures the middle class 12 is more near represented 2 and 3. The middle class 12 exhibits positively formed burls 16 and negatively formed burls 17, which are formed out in relation to a centre plane 18 of the middle class 12. The positively formed burls 16 and negatively formed burls 17 are arranged in lines 19 and columns 21, whereby in the remark example the line space and the column distance are trained directly. Also irregular distances can be intended, in order to obtain if necessary special effects, in particular when bringing in deformations. The line space and the column distance determine themselves from the center a a burl of the 16, 17 to the center of the neighbouring Noppe17, 16. The burls 16, 17 are alternating thereby along the lines 19 and columns 21 together-bordering arranged, so that between two positively formed burls 16 a negatively formed burl 17 and in reverse intended is. Thus results a grid 22, which is to be taken in the plan view in accordance with figure 2 and in the sectional view in accordance with figure 3. Those positively and negatively formed burls 16 and 17 exhibit a lateral surface 23, which changes into a ground 24. The exterior the ground 24 of the burl 16, 17 forms the front surface 26 and 27 of the burls 16 and 17, on which the layer 13, 14 is applied.

Between two beabstandeten to each other positively formed burls 16 and negatively formed burls 17, which were in each case on a straight line, which runs diagonally to the lines 19 and columns 21, are a connecting section 28 trained. This connecting section 28 is favourable-proves as three-dimensional transition trained as the neighbouring burls 16, 17. In the remark example the connecting section 28 is trained partly even and lies in the range of the centre plane 18. This connecting section 28 forms at the same time a neutral fiber of the composite slab 11, whereby a composite slab 11 independent in the installation direction is creative. This comes out for example from a sectional view along the line II in figure 2, which is represented in figure 1 as side view over the thickness of the composite slab 11.

Between a positively formed burl 16 and a negatively formed burl 17 a transient area 29 is trained, which bereichsweise is at least straight-lined by the front surface 26 of the burl 16 up to the front surface 27 of the burl 17 trained. Thus favorable power transmission conditions are created. If the distance between the burls 16, 17 is more largely held, the transient area can be also staged trained.

By the rasterförmige arrangement in accordance with figure 2 a multiplicity of burls 16, 17 can be trained, whereby the load and the rigidity are given to 26, 27 of the burls 16, 17 and the layer 13, 14 due to the increased contact area between the front surface.

In the remark example the burls 16, 17 are kegelstumpfförmig trained. Favourable way is smaller the diameter of the front surface 26, 27 than the distance area between two positively formed 16 or two negatively formed burls 17. The composite slab 11 in accordance with this execution form exhibits for example a diameter 30 of a front surface of 5.5 mm up and a distance area 31 and/or a maximum distance between the boundary regions of to each other beabstandeten positively formed burls 16 or negatively formed burls 17 of 9 mm. A relationship between the distance area 31 and the front surface 26, 27 of less than 1:1,5 is particularly favourable for the arrangement of the middle class 12. Thus a sufficiently thick ground can be trained 24 of the burls 16, 17 and a sufficiently rigid lateral surface 23, in particular in the transient area as the ground 24 of the burls 16, 17. Beyond that the arrangements of the connecting sections 28 exhibit the advantage that during forming the burls 16, 17 sufficient following of the material takes place into the burls 16, 17. Due to the deformation of the burls 16, 17 reciprocally to the centre plane 18 a formation of the burl 16, 17 is necessary only around the half height for the training of the middle class 12, whereby again a increased amount is made available at material for those positively and negatively formed burl, in order to train this more rigidly.

The total strength of the composite slab 11 is determined by the wall thickness of the layers 13, 14 and by the height of the burls 16, 17. In accordance with the remark example it is intended that the height of the positively formed burl and the height of the negatively formed burl are trained directly and are certain by the formation moving in opposite directions of the burls the overall height of the middle class 12. The composite slab 11 can be trained also by different materials. For example the middle class 12 from a impacttough plastic can to be trained and the layers 13 and 14 be able from one of this deviating plastic material to be trained. In dependence of the application also the layers can be in each case from each other trained 13, 14 and the middle class 12 deviating. Likewise it can be intended that between the front surfaces 26, 27 of the burls 16, 17 and the layer 13, 14 a further plattenförmige layer is arranged, which can exhibit additional functions. With different materials of the layers 13, 14 also the wall thicknesses can be differently trained, if the symmetry is to be maintained regarding the maximum stress of the composite slab. Likewise it can be intended that by different materials of the layers 13, 14 or unequally thick layers 13, 14 with same materials a spanning is brought into the composite slab 11. Likewise different thicknesses of the layers can be intended 13, 14, if for example on a layer 13 or 14 a further layer is applied, as for example a carpet, in order to adjust the spanning of this carpet layer or such a thing.

The layer 13 and 14 is trained at their exterior as flat surface. For certain applications further layers can be partly or completely glued on or up-covered. For example can be applied applied or even foam material layers or special insulating layers or interfaces, which are leading or are resistant regarding certain media, on the layer as layer on the middle class. Also metallic, not-iron-metallic layers can be intended as layer 13, 14 as well as from alloys existing light alloy layers as for example an aluminum alloy.

in figure 4 a cut is represented along the line IV-IV in figure 2, whereby additionally in relation to figure 2 the layer 13 and 14 on the front surfaces 26, 27 of the burls 16, 17 is intended. From this sectional view likewise as from the figures 1 to 3 the symmetrical structure of the composite slab 11 follows. The layers 13, 14 and the front surfaces 26, 27 of the burls 16, 17 are warmed up before the Aufkaschieren and pressed against each other under light pressure, whereby welding the layers 13, 14 takes place. Alternatively that additionally on the front surfaces stick-supporting materials or connectingactivating materials are applied, in order the connection between the layers can be intended 13, 14 and the middle class 12 to increase.

In figure 5 a procedure for the production of the composite slab according to invention 11 is represented.

The middle class 12 is manufactured either separately and made available as roller race or as disk material. Alternatively the middle class can be intended 12 manufactured and as the first station of a production line also by a rolling or a pair of volumes. Accomplished by the rolling or pair of volumes favourable-proves a Vorrecken of the material for the production of a middle class 12 with positive and negatively formed burls of same quality, in particular regarding the wall thickness. The before-strained layer is sucked in by a vacuum sucking in to a roller or a volume, in order to form by vacuum deep-drawing the end form of the burls of the middle class.

Following the production or supply of the middle class 12 this is supplied to a laminating station 41. Here it is intended that the layers 13, 14 prefabricated supplied or that these are supplied directly from an upstream extrusion station. The layers 13, 14 favourable-proves at the same time up-covered on the middle class 12. Thus smaller internal voltages in the composite slab 11 can be obtained. Before the middle class runs 12 into the laminating station 41, at least the front surfaces 26, 27 of the burls 16, 17 are heated by a heating or an irradiation unit 39. The middle class 12 favourable-proves before-strained before the supply into the laminating station 41 in at least transverse direction, in order to exhibit after the cooling small internal voltages between the layers 13 and 14 and the middle class 12. The middle class 12 is such supplied that the lines 19 and columns 21 of the burls 16, 17 are diagonally aligned for promotion direction.

After the Aufkaschieren of the layers 13, 14 the composite slab 11 of a cooling station 46 is supplied. In a following gumption unit 51 the composite slabs 11 are prefabricated on pre-determined lengths. Alternatively it can be intended that the lamination of the layers 13 and 14 takes place successively, in order to obtain via Vorreckung in the individual intermediate stages a smaller internal voltage in the composite slab 11.