Description of the problem During manufacturing of light building panels there is much of time wasted for filling of light building panels cavities (also known as deep waves, and used in this application interchangeably). Therefore, the process should be automatized to increase productivity.

Using prefabricated profiles for filling of light building panels cavities which can be obtained by sawing, cutting or milling (see also patent SI 9800006) the use of material and resulting waste increases, and this increases the cost of the production not to mention ecological aspects of increased waste. The cavities act as ribs therefore increasing stiffness of panels. The stiffness is increased more using additives for increase of stiffness in comparison with simple filling of cavities with inserted or pressed-in filling.

State of the art Roof panels or panels with deeper cavities are at present filled with milled, cut or sawed mineral wool manufactured in accordance with cavity cross section whereas large quantities of waste material are generated. At the same time additional material (mineral wool) is needed for cavity filling which increases cost of purchasing and warehousing and resulting production cost. The technology for manufacturing of prefabricated wool profiles for filling the cavities is expensive and needs manufacturing tools prone to wear and tear.

The waste wool presently produced during light building panels manufacturing is not used for filling of cavities. Rather, additional material is used increasing waste and resulting in increased price of finished product and problems associated with waste disposal (ecological aspects).

Description of new invention The subject of new invention is method for preparation of filling waste mixture, preferably mineral wool, and filling of cavities of light building panels as well as device for performing said method. Filling waste refers to the filling material to be discarded such as mineral wool or other insulation filling remaining in the process of manufacturing of light building panels. The main advantage of this invention is in use of existing filling waste produced during earlier phases of light building panels manufacturing due to cutting or sawing of filling as well in use of waste panels made of filling. In this application the word"sawdust"is used interchangeably as common descriptor for all described mineral filling waste material used in the process. The cavities or deep waves for the purposes of this application describe protruded ribs (i. e. ribs extended from the surface of the light building panel) running along light building panels regardless of their depth to width ratio, their purpose being preferably increase of stiffness (rigidity) of light building panels as well as other along light building panel running and from light building panel center (kernel) extended protrusions regardless of degree and/or size of the protrusion.

A method for filling waste mixing, preferably mineral wool and filling of cavities of light building panels comprises steps of collecting of sawdust, transporting of said sawdust into a rotary mixer such as mixing drum, mixing of said sawdust with adhesive and water, unloading of said mixture onto a transporting means, preferably conveyer belt, loading appropriate dose of said mixture into at least one extruder chute, extruding said mixture from said extruder or plurality thereof into cavities of light building panels, pressing of said mixture into said cavities of light building panels.

A device for preparation of filling waste mixture, preferably mineral wool, and filling of cavities of light building panels comprises storing means for storage of a sawdust, preferably accumulator, transporting means for transporting said sawdust to mixing means, preferably conveyer belt, mixing means for mixing of said sawdust with adhesive means, preferably rotary mixer such as mixing drum, and filling means for filling of said mixture into cavities of light building panels, preferably conveyer belt for transport of said mixture from rotary mixer into an extruder chute, an extruder for filling said cavities of light building panels, and pressing means for pressing of said mixture into said cavities of light building panels connected thereto.

Extruders, preferably of worm (screw) type comprise extruder nozzles which are chosen according to size of the cavities: larger the cross section of said cavity larger nozzle is to be used. On the other hand, however, there is no need to change the nozzle for different form of cavities provided that different cavities cross section size are of the same order.

If there is any surplus material said material can be removed into holding receptacles and reused at later time.

Regulating the pressure force forcing mixture into the cavity also regulates compactness of the profile which has advantageous effects on rigidity of the panel. If appropriate additives are used the mixture partially sticks to the building panel metal sheet (said metal sheet acting as light building panel outer boundary) and thereby improvement of mechanical characteristics of said panel is ensured. Essentially advantage of process as described herein is also in fact that cavities of various forms and/or cross section sizes can be filled without change of an extruder nozzle.

Additional advantage of said device for performing the method as described herein is that there are no cutting tools such as saws, mills or other material removing tools hence no cost due to wear and tear of these tools exists.

The device and method for preparation of mixture of waste mineral wool and filling of the panels cavities are developed to ensure simple, flexible, and cost effective design of equipment for manufacturing of light building panels with mineral wool or other insulation material filling and are connected to method of mixture preparation, said mixture comprised of waste wool particles such as cuttings as well as actual filling of cavities of light building panels within the continuous manufacturing of light building panels line framework. The device and the method can be integral part of line for continuous manufacturing of light building panels.

The new invention is described in more detail below with description of embodiments and drawing whereby the drawings make integral part of this patent application and show: Figure 1 presents frontal view of system for preparation of mixture of mineral wool waste and filling of cavities of light building panels comprising accumulator (1), loosening mechanism (2), conveyer belt with partitions (3), rotary mixer (4) in form of mixing drum, conveyer belt (5), extruder (7), conveyer belt (8), belt press (9), heating system (10), system for dosage of water with added chemical additive or plurality thereof for solving adhesive on wool fibers (11), worm (screw) for administering dose (12), mixer (13).

Figure 2 shows top view of system for preparation of mixture of mineral wool waste and filling of cavities of light building panels showing extruder chute (6).

In preferred embodiment, the method and device for its implementation for preparation of mixture of mineral wool waste and filling of cavities of building panels show as input material fragments of mineral wool waste (for purposes of this application denoted also as"sawdust"), said sawdust arising from manufacturing processes such as sawing, cutting, milling of side profiles and other processes for manufacturing of light building panels (sawing of panels, recycling of wool cut from the panels, waste panels etc.). This sawdust is first lead into an accumulator (1) using suction systems placed at the points of sawing or cutting of mineral wool in the process of light building panel manufacturing. From this accumulator (1) in form of a container (silo) said sawdust is loaded essentially uniformly onto the conveyer belt (3) via loosening mechanism. Said conveyer belt (3) in this embodiment comprises partitions and essentially uniformly transports the sawdust from the accumulator (1) in order to ensure essentially steady dosage of said sawdust into rotary mixer (4). The rotary mixer (4) in form of a mixing drum is tilted in order to ensure appropriate speed of mixing and essentially uniform dispensing of said mixture from said rotary mixer (4). Said mixer (4) comprises device for ensuring mixing (13) for purposes of this application denoted also as"mixer", said mixer (13) providing for swift mixing and good wetting of wool particles. In this embodiment the rotary mixer (4) comprises front side attached system for dosage of water with added chemical additive or plurality thereof for solving adhesive on wool fibers (11). This system (11) according to this embodiments comprises reservoir, pump driven by frequency regulated motor for pumping of mixture, and piping system comprising at least one spraying nozzles.

On the entrance side of the mixer a worm (screw) for administering dose (12) extends into the mixer said worm administering appropriate quantity of adhesive onto wetted fragments of mineral wool.

The rotary mixer for purposes of this application denoted also as mixing drum (4) comprises a mixer (13) for mixing of components introduced into the mixer. Optimum mixing parameters can be achieved taking advantage of frequency regulation and mixer tilt regulation.

The chemically reacting mixture is then dispensed into the tub from which the conveyer belt (5) transports toward at least one extruder chute (5). The extruder (7) or plurality thereof, in this embodiment of worm (screw) type is constructed in such a way that the extruder's nozzle or plurality thereof can be elevated to the level (upper level operation) of conveyer belt (8) should the main line be stopped. Said conveyer belt (8) then transports the remainder of the mixture into the recycle bin.

During normal operation (lower level operation) the extruder (7) extrudes the mixture into the cavities of light building panels and fill these cavities until the mixture reaches the upper level of the metal sheet enveloping the panel, i. e. until the cavities are full. To level the mixture separate belt press or plurality thereof (9) is used for each channel (cavity, wave) to impress mixture into each cavity. Then, the mixture within the cavity is dried preferably using heating system (10).

The described invention allows filling of cavities of various cross section forms and sizes. The extruder nozzle should be changed only if the size of cavities between two batches of light building panels changes significantly. Otherwise, the method and device as presented remain unchanged, and this is additional advantage over known state of the art.