A PROCESS FOR THE REALIZATION OF PLATES AND PANELS CONSISTING OF EXHAUSTED OLIVE HUSKS OF CRUSHED OLIVE STONES AND POLYPROPYLENE, AND DERIVED PRODUCT

Abstract: The process according to the present invention provides the use of exhausted olive husks, obtained from the crushing of olives, for playing the role of filling, heat-resistant material, in mixture with the polypropylene, that turns into plastic at a temperature about 230 DEG C, and that has an amalgamating function, so as to determine a complete immersion into the polypropylene of each single particle of olive husks, of different granulometry, by means of the realization of a high temperature mixture, for the realization of listel panels, plates charged with exhausted olive husks powder, multi-layer panels and similar.

Description: "A PROCESS FOR THE REALIZATION OF PLATES AND PANELS CONSISTING OF EXHAUSTED OLIVE HUSKS OF CRUSHED OLIVE STONES AND POLYPROPYLENE, AND DERIVED PRODUCT" The present invention concerns a process for the relization of plates, panels and similar consisting of exhausted olive husks of crushed olive stones and polypropylene, and derived products . The problem of the discharge of the materials resultant from the working in the oil-mills is well known: up to now, these materials are delivered on the soil as compost or burned, with great disadvantages for the ecological ambient. It is the aim of the present invention to positively exploit the olive husks, i.e. the final product of this working, by using it as a constructive means (charge), by mixing it up with plastic materials for the realization of plates and structures of any shape, dimension and colour, for many different uses. The aim set forth is reached by the process according to the present invention, that determines a complete immersion into polypropylene of each single part of olive husks, of different granulometry, by means of the realization of a mixture at high temperature, that may be obtained with extrusion screws. For obtaining the many kinds of derived products according to the aim of the present invention, the percentage of the exhausted olive husks in the constitution mixture is provided for in order of 50-80% in weight. The present invention will be described more in detail hereinbelow, relating to some preferred embodiments. In one embodiment, the process according to the present invention comprises the following phases: - the olive husks are poured onto a conveyor belt that feeds a crushing mill with rotating blades, that provides for a variable granulometry according to tne featuies ol the final product; - the crushed material that flows out of the mill is extracted from the bottom by means of an Archimedean screw and led to the dryer, consisting of a steam burner that makes lower the moisture degree around a value of 5-6%; - by means of a second Archimedean screw, the dried olive husks material is led to a storage silos and from there, by means of pneumatic tubings, transported into the feedbox; - during that extrusion process, the crushed olive stones play the role of filling, heat-resistant material (charge), while the polypropylene, that turns into plastic at a temperature about 230°C, has an amalgamating function; - in the plastiσization phase, the crushed material passes through a central extruder, while the polypropylene is plasticized in a lateral extruder and the plastic material comes out from a plane head; - by means of the shape of the extruders' screws, assembled to injection techniques of the polymer, a plasticized mixture is obtained with a percentage variable between 50% and 80% of crushed exhausted olive husks, with an optimal dispersion, as all particles of olive husks are immersed in said polypropylene. For the realization,in particular of one-layer and multi-layer plates, the product obtained by means of the process according to the present invention is fed into a calender, where it is squeezed and brought to the desired thickness obtaining a plane plate that is now led onto a cooling down roll. Shears and a piling up device allow to perform automatic repeating cuts with the same length and to pile the plates up. Furthermore, three small blades are provided between the calender and the pulling device, for performing the cut of the lateral wastes, as well as the central cut, while the lateral bands are directly led into the mouth of each crushing and re-crushing mill and then prepared for the immediate use by means of an appropriate loading feedbox. It shall be underlined that in the process according to the present invention, virgin polypropylene as well as the recycled one may be used and that therefore two storing silos are provided, one for each kind of polypropylene. For both kinds, and in particular for the recycled one, of which usually the exact origin is unknown, the process according to the present invention provides that it must have an MFI value between 2 and 10, so as to maintain a high productivity. For what concerns the products eventually derived from the process according to the present invention, in some variants thereof they may be the following: - the above mentioned listel panels; - plates loaded with exhausted olive husk powder; - one-layer and multi-layer panels. The plates, having a variable thicknes between 0 and 25 mm, obtained at the end of the extrusion and calendering process, may be used, according to the present invention, as elements in many finished products, as, e.g.: - they may form one or more layers of multi-layer panels consisting of different materials like wood, rubber, etc; - they may be coupled to each other for obtaining the desired thicknesses and physical and thechnological features; - they may be reinforced with fibres, inserting also synthetic materials as glass-fibre, polyester, carbon-fibre, for improving their technological efficiency; - they may be coated and ennobled with different materials, like aluminium, copper, essence of wood, paper with serigraphies , moquette, polypropylene, etc.; - they may be hot-shaped and printed according to the desired drawing and geometry. All above described workings must be performed by pre-heating the single plates in an appropriate oven for bringing them to a temperature depending on a plurality of factors and that may vary between 80°C and 130°C. With a feeding belt connected to said oven, the plates are placed onto the press bank in a number variable according to the final product to be obtained. The press acts onto the pre-heated plates with a constant and uniform pessure, variable according to the thickness, to the mould of the components and to the final destination of the product. During pressing - which depends on above mentioned variants - the cooling phase takes place, during which the material returns to its final density. The panels thus obtained are now edged and squared. IP. a possible variant, a further, parallel and/or successive working cycle may be coupled to the one already described, having for purpose the use of the exhausted olive husks of greater granulometry (5 to 8 mm), discarded in the extrusion process and which, together with other olive husks of smaller granulometry, may be mineralized so as t be used as inert in mixing processes with many binders, in particular with cement. The obtained conglomerate has a high resistance to compression, provided by the short fibre of the olive husks, and may therefore be used for the production of industrial modular elements, like bricks, and in particular for the production of hand-made vibro-compressed materials like the self-blocking blocks for external flooring which at present are realized with inert materials taken from quarries and/or rivers. The product obtained according to said variant is a valid alternative to the exploitation of the ground, with a further protection of the ambient. In a further variant according to the present invention, the plates or panels obtained with exhausted olive husks may be reinforced by using glass-fibre, polyester or carbon, in a coupling between the plate and the fibres (one-layer or multi-layer), as well as a component of the mixture, in the mixing and extruding phase of the plates. This treatment considerably improves the physical and mechanical features of the final product, in particular those that concern the elasticity module and the pulling resistance, thus opening the possibility of use in many uses difficult for the conventional panels like lofts, constructions with lamellar beams, etc. Furthermore, the use of said fibres allows to reduce, maitaining the known resistance, the thicknesses of the panels, with a further improvement of the efficiency for what concerns the weight, the transport, the assemblying, the working. A tridimensional aspect may be given to the plates and pannels obtained according to the present invention, by a simple printing operation. It is known that this shaping - that concerns the thickness of the panel and that may also concerns the aesthetic aspect (ashlar, edging, frames etc.) as well as the statical aspect (ribbings etc.) - may be obtained, in the conventional panels and in wood only by means of complex and delicate working cycles (panelgraphing) , as well as by means of coupling machine-shaped elements according to their thickness and final shape. It is evident that these operation considerably increase the cost of the product, due to the handcraft and apparatuses as well as to the use of raw materials.

Claims: CLAIMS 1. A process for the relization of plates, panels and similar consisting of exhausted olive husks of crushed olive stones and polypropylene, and derived products, and that determines a complete immersion into polypropylene of each single part of olive husks, of different granulometry, by means of the realization of a mixture at high temperature, that may be obtained with extrusion screws, and characterized in the following phases: - the olive husks are poured onto a conveyor belt that feeds a crushing mill with rotating blades, that provides for a variable granulometry according to the features of the final product; - the crushed material that flows out of the mill is extracted from the bottom by means of an Archimedean screw and led to the dryer, consisting of a steam burner that makes lower the moisture degree around a value of 5-6%; - by means of a second Archimedean screw, the dried olive husks material is led to a storage silos and from there, by means of pneumatic tubings, transported into the feedbox; - during that extrusion process, the crushed olive stones play the role of filling, heat-resistant material (charge), while the polypropylene, that 1] turns into plastic at a temperature about 230°C, has an amalgamating function; - in the plasticization phase, the crushed material passes through a central extruder, while the polypropylene is plasticized in a lateral extruder and the plastic material comes out from a plane head; - by means of the shape of the extruders ' screws, assembled to injection techniques of the polymer, a plasticized mixture is obtained with a percentage variable between 50% and 80% of crushed exhausted olive husks, with an optimal dispersion, as all particles of olive husks are immersed in said polypropylene. 2. A product derived from the process according to claim 1, characterized in obtaining listel panels. 3. A product derived from the process according to claim 1, chracterized in obtaining plates loaded with exhaust olive husks powder. 4. A product derived from the process according to claim 1, characterized in ontaining multi-layer panels. 5. A process according to claim 1 for the realization of listel plates , characterized in that the product is fed into a calender, where it is squeezed and brought to the des ired thickness obtaining a plane plate that is now led onto a cooling down rolls Shears and a piling up device allow to perform automatic repeating cuts with the same length and to pile the plates up; and three small blades are provided between the calender and the pulling device , for performing the cut of the lateral wastes , as well as the central cut , while the lateral bands are directly led into the mouth of each crushing and re-crushing mill and then prepared for the immediate use by means of an appropriate loading feedbox. 6. A product derived from the process according to clami 1 , characterized in the realization of plates with variable thickness , obtained at the end of an extrusion and calendering process , and used as components of f inished products , in particular for realizing one or more layers of multi-layer panels composed with dif ferent materials like wood, rubber and similar. 7 . A product derived from the process according to claim 1 , characterized in the realization of plates with different thickness, obtained at the end of the extrusion and calendering process, like glass-fibre-reinfreed plates, alternated with synthetic material (glass-fibre, polyester, carbon-fibre, etc. ) . 8. A product derived from the process according to claim 1, characterized in the realization of plates with variable thicknesses, obtained at the end of the extrusion and calendering process, coated with different and/or hot-shaped and printed materils. 9. A process according to claim 1 ,characterized in the use of exhausted olive husks with great granulometry ( 5 to 8 mm), decarded from the extrusion cycle, mineralized together with olive husks with smaller granulometru, to as to be used as inert material in mixing processes with different binders, in particular with cement. 10. A product derived from the process according to claim 1, characterized in the realization of plates or panels out of exhausted olive husks, reinforced by using glass-fibre, polyester or carbon, in a coupling between the plate and the fibres (one-layer or multi-layer), as well as a com po nen t o f th e mixture, in the mixin g an d e x t ru d ing phase of the plates.

Inventors: CRISTOFARO DOMENICO, CRISTOFARO, DOMENICO
Applicants: CRISTOFARO DOMENICO, CRISTOFARO, DOMENICO
Application year: 1996
Main classification: B27N3
IPC codes: B27N1, B27N3