DE19804787A1 - Continuous production of folding fiberboard material for cupboard rear walls - Google Patents

Abstract

To produce fiberboards which can be folded, a fiberboard is cut into at least two board sections (2a,2b) and positioned with their visible sides (4) together. The flush sections (2a,2b) are aligned at least along the hinge edges (8a,8b) where a hinge connection (16) is to be fitted. The board sections (2a,2b) are secured together with a release bond, and the hinge edges (8a,8b) are worked, for the hinge connection (16) to be fitted and set in place. The fiberboard is cut into at least two board sections (2a,2b) and positioned with their visible sides (4) together. The flush sections (2a,2b) are aligned at least along the hinge edges (8a,8b) where a hinge connection (16) is to be fitted. The board sections (2a,2b) are secured together with a release bond, and the hinge edges (8a,8b) are worked, for the hinge connection (16) to be fitted and set in place. The hinge connection (16) is a synthetic adhesive, or a strip coated with an adhesive. The worked hinge edges (8a,8b) are profiled with chamfers, using hard fiberboards or medium density fiberboards (MDF). A production assembly takes continuous fiberboard material to cut, bond, align, shape the edges and attach the hinge connections using at least two fiberboard sections (2a,2b). The fiberboard sections (2a,2b) are worked so that the hinge edges (8a,8b) from the dividing cut form the outer edges. While the hinge edges (8a,8b) are being worked and the hinge connection (16) is applied, or after, other edges of the fiberboard sections are worked or the fiberboard section (2a,2b) surfaces are worked.

Description

The invention relates to a method for producing foldable fiberboard, which at least have a visible side. To the fiberboard all pay using Lignocellulosic fiber boards, for example hardboard or medium density fibreboard (MDF). Such panels are used, for example, as cabinet back walls used.

For a long time, the back wall of a cabinet was built from individual fiberboard separate connecting elements were connected and fixed together. To the However, minimizing handling of individual parts has been going on for some time wanted to produce dismantled cabinet back panels that can be assembled without tools can.

Known methods for the continuous manufacture of interconnected Plate parts are, for example, in German Patents 8 38 361 (Dichmann) and 44 18 274 (BHF). Both methods have in common that they are in continuous Manufacturing processes can be integrated. This is an unconditional requirement for this To be able to offer bulk items without unnecessary manipulation at minimal prices.

DE-PS 8 38 361 proposes a plate from which the to each other connecting fiberboard parts are to be produced, first provided with grooves, the grooves then being covered by a connecting element. Eventually then the bottom of the groove is milled away from the other side and the individual, together connecting plate parts are arranged on the connecting element. This method is unsuitable for the production of furniture back panels, because it cannot be used for panels at least one visible side can be used because this procedure is carried out both surfaces of the plate can be machined.

In DE-PS 44 18 274 a method is described which is used to produce foldable Back walls for furniture, i.e. for fiberboard with at least one visible side is suitable. This method, which takes up the steps of DE-PS 8 38 361, is also first milled a groove, then the connecting element is applied and finally the bottom of the groove is cut by machining the visible side. The through that Connecting element connected plate parts are then folded so that the visible sides have turned towards each other. This process is very complex to carry out. The Machining the fiberboard on the visible side without damaging the groove with the Connecting element is hardly possible without causing damage on the visible side of the  Fiberboard or on the connecting element comes. The folding of the fiberboard parts Applying the connecting element and milling the second groove often leads to Damage to the connector.

It is therefore an object of the invention to provide a simple and inexpensive method for to propose continuous manufacture of foldable fiberboard.

This object is achieved by a method with the features of claim 1. The starting product for the production of foldable fiberboard is at least one side coated or otherwise rewarded by a continuous Processed fiberboard. The one coated with lacquer or decorative paper, for example In the following, the page is called the view side. The - mostly uncoated - second side of the Fiberboard is referred to below as the screen side.

The starting fiberboard from which the foldable fiberboard is to be made is first broken down into at least two fiberboard parts by a separating cut. The cut can be done from the visible side as well as from the sieve side. The two fiber Plate parts are then turned with the help of appropriate turning devices, for example with the help a turning star or a lever arrangement, placed on top of each other. The Visible sides of the fiberboard parts turned towards each other.

This step of completely separating the single output fiberboard and the subsequent turning of the fiberboard parts is new and related to that Further processing of fiberboard into furniture parts is extremely unusual. The so far pursued approaches have always avoided such a step because the turning and Aligning the plate parts to the specialist as cumbersome, complex and space-consuming intermediate step appears. So far, it has always been preferred Further processing, if possible, on one level continuously or continuously to let linked conveyor systems run through, and only after the plate parts Attach the connecting element to fold. Any interruption of the continuous Promoting or even manipulating plate parts was seen as a measure that reduces the performance of the production plant.

However, it has proven to be a great advantage in experiments that the continuous Manufacturing of foldable fiberboard in the sequence of the steps of claim 1. On Separation cut with which the original fiberboard is completely broken down into two fiberboard parts can be carried out with an easy to adjust saw. It is not an expensive one Setting a precise depth of cut is required, as is the case when making a groove necessary is. If the cut is made from the visible side, the  Visible side at the cutting edge largely avoided because the saw on the screen side of the Fiberboard emerges and consequently any tears in the area due to the cut resulting edge lie on the sieve side. This process has a particular advantage also that straight edges are generated that do not require any further processing. These edges, hereinafter referred to as outer edges, are after turning Stop on. The edges on the outside of the original fibreboard, below Called connecting edges can now be so according to the inventive method processed that not only the connecting element can be applied, but that the finished plate parts have exactly the specified dimensions.

The turning of the plate parts can be done with the simplest tools, which are plate parts freely movable and easy to manipulate. In contrast, the panels must be folded according to the method described in DE-PS 44 18 274 with great care, that is with be carried out according to precisely adjusted machines to ensure that the plates are not moved against each other, so that the connecting element is damaged.

The fiberboard parts are then aligned so that they are along one Connection edge can be connected to each other. Aligning the plate parts happens with the help of simple stops on which the at least two plate parts by means of Conveyors are aligned. As already explained, the plate parts with the outer edges created by the separating cut are aligned with the stops. The edges on the outside of the output fiberboard, the connecting edges, are marked by this orientation accessible to the other processing devices. The flush Aligned fiberboard parts are then releasably fixed so that they can be used for the following Processing steps remain in a defined position to each other. It is preferred that Fix fibreboard parts after alignment using a clamping device. Suitable clamping devices are, for example, spring-mounted pairs of rollers, the pressure exert on the superimposed fiberboard parts.

The fiberboard parts are then processed along the connecting edge. in the in the simplest case, the connecting edge is chamfered from the sieve side to the visible side, to create a good adhesive surface for the connecting element. However, it is also possible to profile the connecting edge, for example when the connecting element should be flush with the level of the screen surface. The advantage of this procedure is that these work steps can be constantly monitored optically, and that adjustments and changes in the setting can be made simply because the required processing devices arranged laterally and thus easily accessible are. In the prior art methods described above, the  Fiberboard across the entire width of the conveyor or across the conveyor Machined in the middle of the conveyor line and there are milling and application devices for glue and the like on both the visible surface side and the screen surface side required. In contrast, in the method according to the invention, all are Machining devices attached to the side of the conveyor line, because it only has to the connecting edges of the fiberboard parts are machined since the outer edges already are completely processed. A particular advantage of the method according to the invention is seen in that by the successive processing of parallel edges individual, assigned fiber board parts the specified dimensions and Angles can be maintained particularly precisely and with minimal effort.

If necessary, the connecting edge is still for application after processing prepared the connecting element, for example by applying a seal or an adhesive component.

Finally the connecting element is applied. As a connecting element in In the simplest case, an adhesive is applied, preferably a synthetic adhesive on the base of polyurethane. Such adhesives are offered as hot melt adhesives, for example a PUR adhesive with a viscosity of 22,500 ± 7,500 mPa.s at 120 ° C and one Processing temperature from 120 ° C to 140 ° C. But it is also possible that an adhesive tape, if necessary, e.g. B. a fabric or foil tape as Connection element is used.

Depending on which glue is used, the fiberboard parts will now be like this fixed for a long time until the adhesive has hardened. If necessary, pass through the fiber plate parts at least in the region of the connecting edge provided with the connecting element a device for curing the adhesive.

After the connecting element has been applied and possibly hardened, the Fixing device released and the foldable fiberboard is now immediate, without further Manipulations must be made ready for dispatch. It proves to be advantageous here that the visible surface from the beginning of processing before damage or Contamination is protected. Dripping glue, dust or damage due to Saws or milling arranged on the visible side are in the method according to the invention locked out.

Depending on how the production systems are designed, the devices for Carrying out the process either stationary or movable, so that the fiberboard parts can be processed either continuously or in a resting position (cyclically). With regard  to the higher performance in the continuous production by means of conveyor lines the devices for carrying out the method, the clamping devices, the saws or milling for processing the connecting edge and the devices for applying of the connecting element is preferably arranged stationary and the plate parts are on the Devices moved past. But it can also prove to be useful that Devices for performing the process and the fiberboard parts at the Perform the procedure in the same or opposite direction.

Exemplary embodiments of the invention are described in detail below with reference to figures described. Show it

Fig. 1 is a perspective view of two fiberboard parts after separation

Fig. 2 is a perspective view of two superimposed and aligned fiberboard parts

Fig. 3a shows a perspective view of two processed at a connecting edge fiberboard parts

FIG. 3b is a perspective view of two at a connection edge processed fibreboard parts

Fig. 4 is a perspective view of two fiberboard parts foldably connected by means of a connecting element

Fig. 5 is a side view of two fiberboard parts connected by a synthetic adhesive in the folded state

Fig. 6 is a side view of two fiberboard parts connected by a synthetic adhesive in the folded state

FIG. 6a is a side view of the two connected by a synthetic adhesive fiberboard parts according to Figure 6 in folded-out condition.

Fig. 7 is a side view of two fiberboard parts connected by an adhesive tape.

The continuous production of foldable fiberboard, which in particular as Furniture back panels are used, generally immediately follows the Production of an endless band of fiberboard. The one-sided coated Endless fiberboard is at least as wide as the maximum width of the back of the furniture and has a thickness between 1.5 mm and 8 mm. The continuous fiberboard is made using Cutting saws cut to the length required for the back of the furniture. The on the The appropriate length of shortened fiberboard may need to be cut to the appropriate width become. To - especially for furniture that is offered as a kit in flat packages - To achieve convenient transport dimensions, the fiberboard is often only half the width of the Have furniture. Therefore, the fiberboard must be foldable. The procedure  To produce such foldable fiberboard, the simple process must be simple and inexpensive manufacture of large quantities.

Fig. 1 shows two hardboard parts 2 a, 2 b with a material thickness of about 3.5 mm, which are coated on the visible side 4 with decorative paper. The screen side 6 is unprocessed and uncoated. The parts 2 a, 2 b have after the separation of opposed outer edges 10, 12. The outer edges 10 , 12 are clean and aligned parallel to each other after the separating cut. Parallel to the outer edges 10 , 12 , but at the opposite ends of the parts 2 a, 2 b, the connecting edges 8 a, 8 b lying on the outside in the starting fiberboard run. The term "joint edge" indicates that the plate parts 2 a, 2 b a the region of these edges 8 a, 8 b disposed link member 16 are pivotably or foldably connected to each other. The connecting edges 8 a, 8 b have irregularities and are not yet prepared for the application of a connecting element 16 .

The two parts 2 a, 2 b are, as indicated in FIG. 1 by the arrow P and shown in FIG. 2, folded by means of suitable, not shown turning devices with the visible sides 4 to one another. As turning devices, for example, turning stars or simple lever arrangements or scissor turner can be used. The turning devices can be simple because no great precision is required.

After turning, the connecting edges 8 a, 8 b are arranged one above the other. The fiberboard parts 2 a, 2 b are then aligned so that the connecting edges are flush with one another. Simple stops against which the outer edges 10 , 12 rest are sufficient for alignment. The flush-aligned parts 2 a, 2 b are fixed by releasable clamping devices, preferably pairs of clamping rollers 14 (pressure direction: arrow F in FIG. 2), which are each arranged above and below the two parts 2 a, 2 b. Springs, pressure rollers or the like are also suitable. The clamping device may also be a means of transport for conveying the parts 2 a, 2 be combined b, z. B. in the manner of a pair of conveyor belts with pressure rollers.

The parts 2 a, 2 b fixed in this way are now processed in the region of the connecting edges 8 a, 8 b in order to create a suitable contact and adhesive surface for a connecting element 16 . The processing is expediently carried out with milling or sawing. In the simplest case, the connecting edges 8 a, 8 b, as shown in Fig. 3a, beveled, so that the parts 2 a, 2 b have an approximately wedge-shaped profile. If the connecting element 16 itself has a certain material thickness so that it could protrude beyond the screen side 4 after attachment, the processing of the connecting edges 8 a, 8 b can also lead to a stepped profile according to FIG. 3 b. Concave or convex connecting edges 8 a, 8 b can also be produced for special applications.

After the connecting edges 8 a, 8 b are processed, the connecting element 16 is applied. The connecting element 16 , as shown in FIGS. 5 to 6, is preferably a suitable synthetic, meltable adhesive, preferably a polyurethane adhesive. A suitable adhesive is, for example, Jowatherm® reactant (manufacturer: Lobers and Frank GmbH & Co. KG, Detmold).

The adhesive is applied by means of a suitably shaped nozzle (not shown here), the shape of which ensures that the adhesive is applied completely to the machined connecting edge 8 a, 8 b, and that a predetermined profile for the connecting element 16 is maintained. Examples of such predetermined profile, Figs. 5 to 6. The profiles are chosen so that they stabilize the fiberboard parts 2 a, 2 b in the unfolded state, by the by machining of the joint edges 8 a, 8 b incurred Fill in the space (see Fig. 6a). The application device for the adhesive is optionally arranged directly in front of a device for curing the glue, for example a cooling system or a UV system. This measure ensures that just when a predetermined profile is to be maintained, the adhesive is fixed in the predetermined shape immediately after application.

Fig. 7 shows plate parts 2 a, 2 b, which have profiled connecting edges 8 a, 8 b. The connecting edges 8 a, 8 b comprise a shoulder 18 a, 18 b and a slope 20 a, 20 b. The advantage of this profile is that, despite the material thickness, the adhesive tape made of fabric used here does not protrude beyond the screen sides 6 a, 6 b of the plate parts 2 a, 2 b. This is particularly advantageous when stacking the foldable fiberboard, because completely flat stacks are packed.

Another especially preferred embodiment of the process of the invention provides that the outer edges 10, 12 of the fiber plate parts 2 a, 2 b serve as connecting edges, so that the edge produced by the severing cut to outer edges of the foldable fiber plate. This procedure has the advantage that the absolutely parallel edges created by the separating cut result in a suitable closure of the foldable fiberboard, while the outer edges 10 , 12 still require processing anyway. Thus, if the outer edges 10 , 12 are used as connecting edges, machining these connecting edges eliminates one operation, since there is no need to straighten the outer edges of the foldable fiberboard. In view of the extreme cost pressure on these products, this creates a significant cost advantage.

It is obvious that the arrangement of the means for Processing the fiberboard parts and the means for applying the connecting element as well as for curing the connecting element on the side of the conveyor line or to the side of the plate opposite the arrangement of these means in the middle above the fiberboard also contributes to reducing costs. The devices mentioned are easier to monitor and adjust and the correct application of the connecting element is easier to do and can be done immediately after application. Should there be any undesirable deviations here, the corresponding ones can Devices can be reset without delay.

In the case of methods according to the prior art, the time interval between the Process and product control that only takes place when the interconnected ones are folded Plate parts are made, much larger, so the share of committee. Through this there is a risk that damage caused by the incorrect manipulation of foldable fiberboard under stress the fasteners arise as incorrect work of the aforementioned devices are considered. This will then overcorrections are triggered which cause further rejects to be generated. It lies on hand that the inventive method cheaper, easier and is more reliable than the state of the art.

Claims (10)

1. Method for producing foldable fiberboard, which have at least one visible side ( 4 ), with at least two fiberboard parts ( 2 a, 2 b), which at least in sections along a connecting edge ( 8 a, 8 b) by a connecting element ( 16 ) connected with each other, with the steps

• - separating a fiberboard by a cutting in at least two fiber plate parts (2 a, 2 b)
• - superimposing the two fiber plate parts (2 a, 2 b), the visible sides are returned (4) to each other,
• - Aligning the fiberboard parts ( 2 a, 2 b) at least along the connecting edges ( 8 a, 8 b), on which the connecting element ( 16 ) is arranged,
• - Detachable fixing of the two fiberboard parts ( 2 a, 2 b),
• - Machining the connecting edge ( 8 a, 8 b) on each of the fiberboard parts ( 2 a, 2 b),
• - Attach and, if necessary, harden the connecting element ( 16 ).

2. The method according to claim 1, characterized in that the connecting element ( 16 ) is a synthetic adhesive, in particular a hot melt adhesive based on polyurethane. 3. The method according to claim 1, characterized in that the connecting element ( 16 ) is an optionally coated with adhesive tape. 4. The method according to at least one of claims 1 to 3, characterized in that the connecting edge ( 8 a, 8 b) is profiled during processing. 5. The method according to at least one of claims 1 to 3, characterized in that the connecting edge ( 8 a, 8 b) is chamfered during processing. 6. The method according to at least one of claims 1 to 5, characterized in that Hardboard or medium density fibreboard can be processed. 7. The method according to at least one of claims 1 to 6, characterized in that fixed means for fixing the aligned fiberboard parts ( 2 a, 2 b), means for processing the edge ( 8 a, 8 b) on which the connecting element ( 16 ) is arranged, and means for applying the connecting element ( 16 ) are provided, and that the fiberboard parts to be connected ( 2 a, 2 b) are continuously guided past these means in order to connect the connecting edges ( 8 a, 8 b) edit and to attach the connecting element ( 16 ) on the edges ( 8 a, 8 b) of the at least two fiberboard parts ( 2 a, 2 b). 8. The method according to at least one of claims 1 to 6, characterized in that the means for processing the edges ( 8 a, 8 b) on which the connecting element ( 16 ) is arranged and the means for applying the connecting element ( 16 ) the aligned and fixed fiber plate parts (2 a, 2 b) are passed to the connection edges (8 a, 8 b) to edit and to the connecting element (16) at the edges (8 a, 8 b) of the at least two fiber plates Parts ( 2 a, 2 b). 9. The method according to at least one of the preceding claims, characterized in that the fiberboard parts ( 2 a, 2 b) are placed one on the other in such a way with the visible sides ( 4 ) that the resulting edges by the separating cut ( 8 a, 8 b ) are the outer edges ( 10 , 12 ). 10. The method according to at least one of the preceding claims, characterized in that during or after the processing of the connecting edges ( 8 a, 8 b) and the application of the connecting element ( 16 ) other edges ( 10 , 12 ) of the fiberboard parts ( 2 a , 2 b) are processed, or that the surface of the fiberboard parts ( 2 a, 2 b) are processed.