EP0459271A2 - Process for the continuous or sequenced manufacture of plates and/or products from water setting, fibre reinforced materials and obtained plates and/or products - Google Patents

Abstract

Problems exist in the conventional process inasmuch as such plates often tend to exhibit deformations, since their structure is not fully symmetrical. Such deformations may also be produced by different water-cement ratios in the individual layers and the different fibre contents due to different positions of the fibres. In order to provide a plate which is improved in comparison, it is provided that first of all two plate halves with the same structure are prefabricated and the two plate halves are subsequently laid one on the other and joined to each other, achieving a symmetrical overall structure. <IMAGE>

Description

The invention relates to a method for the continuous or clocked production of plates and / or moldings from fiber-reinforced hydraulically setting compositions according to the preamble of claim 1 and associated plates and / or moldings according to the preamble of claim 14.

In particular, the production of plates and moldings made of fiber-reinforced concrete that are symmetrical in their construction always present difficulties in practice.

Since their structure is generally not completely symmetrical, such a plate and / or shaped bodies formed therefrom often tend to deform. Deformations can occur due to different water-cement values in the individual layers, including due to different fiber contents and due to the different position of the fibers.

In a known method, a hydraulically setting mass is applied in a predetermined thickness on a base lying on a continuously moving belt and moving with the belt. Then, in a metered amount, fiber chips coming from a cutting device are sprinkled onto the surface of the continuously moving pre-fixed mass, in order to be pressed into the matrix while moving with a tool that spans the entire working width. The mass is compressed at the same time.

The fiber chips distributed over the mass to be hardened and coming from the cutting unit can be sprinkled on the pre-fixed mass in several successive phases and pressed into the mass to be hardened in various subsequent work steps with a corresponding multiple-strip tool.

After one or more sprinkling and pressing in of fiber chips, as a rule, additional fiber bundles, so-called rovings, are placed and / or drawn into the mass reinforced with fiber chips.

A new layer of hydraulically setting masses can then be applied and, in one or at least one further step, fiber chips coming from the wood chip plant are sprinkled on and pressed into different layer thicknesses using the multi-strip tool.

The above-mentioned manufacturing process can be carried out continuously or in directly successive work steps.

It is an object of the present invention, based on this prior art, to provide a process for the production of plates and / or moldings from fiber-reinforced hydraulically setting compositions, and the associated plates and / or moldings, which are very large compared to the prior art Have a more symmetrical structure that is less prone to deformation and that can also withstand higher loads without the use of additional materials.

The object is achieved with respect to the method according to the features specified in claim 1 and with regard to the plates and / or moldings according to the features specified in claim 14. Advantageous embodiments of the invention are specified in the subclaims.

The improvement according to the invention can be achieved in a simple and extremely economical manner compared to the prior art in that two correspondingly prefabricated plates or moldings are produced from fiber-reinforced hydraulically setting compositions and are placed on top of one another with their upper sides facing one another. Since the two individual halves are prefabricated identically, the overall structure is ideally symmetrical. The symmetrical basic structure also ensures a symmetrical, even water-cement density distribution, which also counteracts deformation. Above all, however, it is ensured by the continuous fibers or rovings inserted in the lower and upper half of the plate that these come to lie exactly in the area in which, above all, the tensile forces are to be absorbed and absorbed. Finally, it can also be ensured that the fiber chips are distributed in a metered amount in each case in the upper and lower plate area from the middle plane of symmetry rather to the outer surface, in which they are needed above all for the absorption of force and / or support. In the neutral middle zone, where they make no contribution to this, you can do without these fiber chips, as well as the rovings. This also results in a higher proportion of cement paste in the middle, which means that the two plate halves can be connected even better.

When joining the still unhardened plate halves, it is therefore not necessary to use an additional adhesive. The use of an additional adhesive or cement paste is only necessary if the individual plate halves have been subjected to a certain amount of pre-hardening or full hardening and drying.

The method according to the invention allows plates such as moldings to be produced from fiber-reinforced hydraulically setting compositions, it not only being possible to produce plates or moldings with a high symmetrical structure and largely uniformity, but above all also a clean, smooth surface on the top and bottom of the plate and if desired, a structured or profiled plate surface can also be achieved. This is because any profiling can be carried out according to the carrier film used or using profiled documents.

Figur 1 :

eine schematische Seitendarstellung während des Herstellungsverfahrens der erfindungsgemäßen Platte während des Auflegens der einen Plattenhälfte auf die andere;

Figur 2 :

eine auszugsweise schematische vergrößerte Querschnittdarstellung durch die endgültige erfindungsgemäße Platte.

Further advantages, details and features of the invention result from the exemplary embodiment shown in the drawings. The following show in detail:

Figure 1:

a schematic side view during the manufacturing process of the plate according to the invention while laying one half of the plate on the other;

Figure 2:

a partially schematic enlarged cross-sectional view through the final plate according to the invention.

FIG. 1 shows a schematic cross-sectional representation of a process sequence when two plate halves are joined, to which reference is made below.

From the drawings, for example, a moving conveyor belt 1 is shown, with which a second 3 ″ is applied in a desired width to an existing plate 3 ′. The plates 3 'and 3' 'can be made, for example, by extruding the hydraulically setting mass through an extruder, the opening of which corresponds to the thickness and width of the plate to be produced. Behind the extruder, a cutting unit is arranged above the conveyor belt, which continuously ejects fiber chips, usually glass fiber chips, in the desired length via a chute, from which the fiber chips are then disrupted and scattered in an oriented manner onto the surface of the mass. Since the mass is continuously moved under the pulp rule, the fiber chips coming from the chute are controllably distributed evenly on the surface of the mass. Then, using a tool in the form of a multiple-bar comb, these fiber chips are pressed into the hydraulically setting mass to a desired depth, for example with a plate that is approximately 3 mm to 3.5 mm thick and approximately 0.5 mm from the underside .

The process explained above can be repeated, for example, the chips being distributed again over the hydraulically setting mass being pressed into the hydraulically setting mass again via the multiple-bar comb, but preferably to a different depth, for example up to 1. 5 mm distance from the underside resting on the moving belt.

In a further process step, continuous fibers, so-called rovings, can be placed and / or drawn into the mass of the panel to be produced. The continuous fibers can be impregnated in a manner known per se.

It would also be possible to lay an endless fiber fabric, which should also be understood under the term "endless fibers". A further layer of hydraulically setting compound 11 can then be applied, as a result of which the lower plate half 3 ', which results in a schematic cross-sectional representation, is ultimately formed, in which the lower first and an overlying second layer with fiber chips 5 and another one above it are schematically formed Layer with continuous fiber or rovings 7 in the hydraulically setting mass 11 are shown. This is followed by no or at least one layer of pulp in z. B. about 4.5 mm from the conveyor belt level.

In order to ensure a symmetrical structure for the plate as a whole, two plate halves, as explained above, are now placed one on top of the other with their upward-facing layers, for example by using a shooting belt 13 shown schematically in FIG simultaneous forward movement is carried out in such a way that the still uncured mass on top, forming the upper plate half 3 ″, is turned by 180 ° and placed on the lower plate half 3 ′.

Since the lower and upper plate halves 3 'and 3' 'were thus produced uniformly and identically in the first process step, this results in a completely identical symmetrical structure. Above all, the introduction of fiber chips into the neutral zone 15 (FIG. 2) could be dispensed with or the proportion thereof minimized, which leads to a shortening and simplification of the production process, combined with a cost saving.

As a result, a higher proportion of cement paste is also available in the connection level 17 in order to optimally connect the two plate halves 3 'and 3' 'to one another.

The manufacturing method explained above can be carried out step by step or in a modified form continuously, whereby either first cut plate halves cut to length and then placed on top of each other or largely continuous strands of plate halves are placed on top of one another and then cut into plates of predetermined length.

The final, thus prefabricated, sandwich-like panels 3 are then stacked on the formwork panel in the trolley until final hardening or brought into a corresponding shaping device, for example for the production of corrugated panels, for deformation.

The above-described method is generally carried out in such a way that a base which is moved with it, for example in the form of a film, a glass fleece or a plastic-coated paper, is always provided on the illustrated conveyor belt. This underlay has a kind of formwork character and can later be removed from the board surface without any impairment and without any residues, which means that a completely uniform, smooth board surface can be produced, which has neither rough spots nor cracks. In the case of a film provided with structural elements, for example, predetermined structural elements or even when using a colored film, pre-coloring of the outer sides of the plates could also be produced. Since, in accordance with the method explained, the plate halves are placed on top of one another with their respectively rough and non-smooth surface on top, it is thus ensured that the final sandwich-like plate has the completely smooth, crack-free and residue-free surface texture mentioned above and below , since both outer sides are now covered by the mentioned pad, which can be removed later. Finally, on the top and bottom of the plate to be hardened, which is assembled from the two plate halves 3 'and 3'', the plate, which preferably consists of a film Underlay is provided, there is also an optimal post-treatment, which ensures a more uniform curing, which significantly improves the quality of the product.

Claims (14)

Process for the continuous or cyclical production of plates and / or moldings from fiber-reinforced hydraulically setting masses, the hydraulically setting mass being applied to an optionally belt-like base and before or after being placed in the hydraulically setting mass in at least one plane fiber chips and also continuous fiber bundle and / or be drawn in, characterized in that two prefabricated plate halves are placed on top of one another and connected to one another, in such a way that the plate structure is symmetrical in the direction of the plate thickness. Method according to claim 1, characterized in that the two plate halves are each joined together with their upper side to form a complete plate. Method according to claim 1 or 2, characterized in that the two plate halves are moved towards one another for joining. A method according to claim 1 or 2, characterized in that one half of the plate is turned through 180 ° and placed on the second lower half of the plate. Method according to one of claims 1, 2 or 4, characterized in that the upper half of the plate is unrolled by a roller by 180 ° when it is placed on and connected to the lower half of the plate. A method according to claim 5, characterized in that the upper half of the plate to be put down on the lower plate half is unrolled by means of a shooting belt which is advanced during the laying down and is turned through 180 °. Method according to one of claims 1 to 6, characterized in that the two plate halves are placed on one another in the still uncured state and are then cured. Method according to one of claims 1 to 6, characterized in that the two plate halves are first hardened or at least hardened, and then joined together using a separate adhesive. A method according to claim 8, characterized in that cement paste is used as the adhesive. Method according to one of claims 1 to 9, characterized in that the fiber chips and / or the continuous fibers are provided and introduced outside the central neutral zone of the final plate. Method according to one of claims 1 to 10, wherein the fiber-reinforced hydraulically setting masses are applied in a first process step to a possibly moving base, characterized in that the base is provided and removable on the top and bottom of the finally produced panel. Method according to one of claims 1 to 11, characterized in that the base has a surface structure. Method according to one of claims 1 to 12 , characterized in that a wallpaper is used as a base. Fiber-reinforced hydraulically setting plate and / or molded body produced at least according to one of claims 1 to 13.

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