PROCESS FOR MAKING A SOLID PRODUCT STARTING FROM HIDES

Abstract

 The present invention regards a process for making a solid product (18) starting from hides. The process comprises a step of arranging a sheet-like element (1) in hides, a cutting step, in which the sheet-like element (1) is cut into a plurality of cut-outs (2), a step of wetting the cut-outs (2) with water, and a mixing step, in which the cut-outs (2) are mixed with a glue (9) comprising natural resins, in order to obtain a mixed product (10). In addition, the process comprises a pressing step, in which the mixed product (10) is pressed in order to obtain a pressed semifinished product (13), and a solidification step, in which the glue (9) of the pressed semifinished product (13) solidifies in order to obtain a solid product (18) with low environmental impact and adapted to be employed in many different applications, as in the clothing field, construction field and furniture/interior design field, etc.

Description

Field of application

[0001] The present invention regards a process for making a solid product starting from hides, according to the preamble of the independent claim 1.

[0002] The present process is inserted in the field of working hides, and in particular in the field of recovery and working of discards deriving from preceding working of hides, so as to obtain new products that can be reused for different uses.

[0003] Advantageously, such new products are intended to be employed in different fields, such as the construction field, e.g. for making insulating panels or covering elements (such as tiles), the furniture/interior design field, e.g. for making the walls of a building (possibly associated with other panels), the clothing and fashion field, e.g. for making clothing articles, footwear, bags etc.

State of the art

[0004] Processes are known for working the hides, which usually provide for cutting-out the hides so as to obtain a shaped element made of hide for making finished products, usually for the footwear field and clothing in general.

[0005] Such processes, as is known, produce a high quantity of working discards, also known as working scraps, which, in addition to determining a waste of material, involve a high disposal cost.

[0006] Following the working of the hides, the discards must in fact be transported and conferred to a side dedicated for the disposal thereof, usually an incinerator or a dump. A further problem tied to the disposal of such working discards lies in the fact that this involves environmental damage, both if the discards are disposed of by means of incinerator, since their combustion determines introductions of gases, ash and dust into the atmosphere, and if they are disposed of in dumps, since they constitute high volumes of waste and their decomposition can involve the release of harmful substances (in particular heavy metals) present within the worked hide.

[0007] In order to at least partly overcome such drawbacks, a process was developed for the recovery of hide working discards which allows their subsequent industrial working in order to obtain new products, described for example in the Italian patent IT 102016000009152 or in the document US 6264879.

[0008] The aforesaid process provides for a cutting step, in which the discards are cut into a plurality of cut-outs, and a subsequent mixing step, in which the aforesaid cut-outs are mixed with glue.

[0009] The process also provides for a pressing step, in which the mixture of cut-outs and glue is pressed in order to obtain a panel which is finally made to dry under air in order to solidify the glue present in the mixture and obtain a finished product.

[0010] In particular, such process provides for the use of a vinyl glue based on water or, alternatively, a glue containing solvents, such as for example a polyurethane glue, neoprene glue, thermoplastic glue or mastic glue, or an animal glue or a latex glue. However, also such process has shown in practice that it does not lack drawbacks.

[0011] More in detail, a first drawback lies in the fact that the products obtained with the aforesaid process contain different synthetic substances (in particular bonded to the employed glues), such as chrome or formaldehyde, which have a high environmental impact for the subsequent disposal of such products. In particular the glues employed have shown themselves to be unsuitable for effectively prohibiting the release of harmful substances that are present in the treated hide, usually deriving from the tanning process, in particular chrome and formaldehyde.

[0012] In addition, the discard residues of such process of known type, in particular constituted by the substances of the employed glues, also resulted particularly polluting, and therefore with a strong environmental impact for their disposal.

[0013] A further drawback of the above-described process of known type lies in the fact that the finished products obtained with such process do not result provided with good physical and mechanical characteristics, and in particular are provided with high rigidity, rendering it poorly suited for applications (such as those of clothing) in which particularly soft materials are requested, also for aesthetic reasons and for consumer appreciation.

[0014] A further drawback lies in the fact that the finished product are not very uniform from the aesthetic standpoint and in particular there are visible defects of poor adhesion of the glue to the cut-outs, which determine a partial separation of the glue matrix from the cut-outs in such point. This is due to the fact that during the mixing step such employed glues are unable to adhere to the cut-outs in an optimal manner.

[0015] Also known from the document US 4497871 is a process for the recovery of hide working discards which provides for the use of a glue comprising natural rubber and naphtha (as solvent).

[0016] However, also such process has proven to be non-ecosustainable, resulting in high environmental impact since it limits the recyclability of the product following its disposal.

Presentation of the invention

[0017] In this situation, the problem underlying the present invention is to remedy the drawbacks of the abovementioned prior art, by providing a process for making a solid product starting from hides which allows obtaining products with low environmental impact.

[0018] A further object of the present invention is to provide a process for making a solid product starting from hides, which can be actuated with an insignificant production of polluting discard residues.

[0019] A further object of the present invention is to provide a process for making a solid product starting from hides, which allows obtaining products usable in many different application fields.

[0020] A further object of the present invention is to provide a process for making a solid product starting from hides, which allows obtaining products provided with good physical and mechanical properties.

[0021] A further object of the present invention is to provide a process for making a solid product starting from hides, which allows obtaining a product that is provided with a sufficient elasticity for the application for example in the clothing and leather fields.

[0022] A further object of the present invention is to provide a process which allows obtaining a finished product provided with high aesthetic properties.

[0023] A further object of the present invention is to provide a process which allows recovering and reusing the hide working discards.

[0024] A further object of the present invention is to provide a process that is simple, which has limited costs and which is attainable with apparatuses of known type.

Brief description of the drawings

[0025] The technical characteristics of the invention, according to the aforesaid objects, can be clearly seen in the contents of the below-reported claims and the advantages thereof will be more evident from the following detailed description, made with reference to the enclosed figures, which represent a merely exemplifying and non-limiting embodiment of the invention, in which:

• figure 1 illustrates an example of the sheet-like elements of the hides used in the present process;
• figure 2 shows a cutting step of the present process;
• figure 3 shows a mixing step of the present process;
• figure 4 shows a pressing step of the present process;
• figure 5 shows an example of the solid product obtained with the present process.

Detailed description of a preferred embodiment

[0026] The process for making a solid product starting from hides in accordance with the present invention allows using hide discards for making new solid products employable in different applications.

[0027] For example, the solid products can be employed for making products for construction (e.g. for making insulating panels or covering elements), for components of buildings and furniture/interior design components (for example for making the walls of a building), for parts of clothing articles or leather articles (such as footwear, bags), etc. In particular, the solid products obtained with the present product can be both intermediate products that are used as starting product in order to obtain finished products, and products that are per se already finished, as discussed in detail hereinbelow.

[0028] With reference to the example of the enclosed figures, the present process comprises a step of arranging at least one sheet-like element 1 made of hides.

[0029] In particular, multiple sheet-like elements 1 can be provided for, with many different shapes and sizes, in particular deriving as discards of the production of products made of hide.

[0030] Advantageously, the sheet-like elements 1 can be of any type of hides, such as leather, goat hide, calf hide, pig hide, etc.

[0031] The present process also provides for a cutting step, in which the sheet-like elements 1 are each cut into a plurality of cut-outs 2, as illustrated for example in figure 2.

[0032] In particular, the cut-outs 2 have size smaller than the sheet-like elements 1 and, advantageously, they can have many different sizes and geometric shapes of various types.

[0033] Advantageously, the aforesaid cutting step is obtained with at least one cutting apparatus 3, preferably of automated type, per se known for the man skilled in the art and hence not described in detail hereinbelow.

[0034] Advantageously, the cutting apparatus 3 comprises a loading station 4, at which an operator loads the sheet-like elements 1 on the cutting apparatus 3 itself, and at least one cutting device 5 (provided with one or more blades 6), which is actuatable (preferably in an automated or semi-automated manner) in order to act the sheet-like elements 1 so as to cut them into the aforesaid plurality of cut-outs 2.

[0035] Suitably, the cutting device 5 of the cutting apparatus 3 can have linear or rotary movement.

[0036] Advantageously, with reference to the example of figure 2, the cutting apparatus 3 comprises a work surface 7 (substantially horizontal) on which the sheet-like elements 1 are arranged (during the aforesaid cutting step) at the loading station 4 (defined for example by a zone of such work surface 7). The cutting device 5 is placed above the work surface 7 and is vertically movable in order to act cyclically on the sheet-like elements 1 placed on the work surface 7 itself. Preferably, the cutting apparatus 3 is arranged for determining a relative movement of the cutting device 5 with respect to the work surface 7, in a manner such that the cutting device 5 can act in succession on different zones of the work surface 7 and hence on different sheet-like elements 1. Such relative movement can be obtained, for example, by actuating the cutting device 5 to be moved horizontally with respect to the fixed work surface 7, or by advancing the work surface 7, along a horizontal advancement direction X, with respect to the fixed cutting device 5 along such advancement direction X.

[0037] In accordance with a different non-illustrated embodiment, the cutting apparatus 3 is constituted by a cutter with rotary rollers, in which the cutting device 5 comprises one or more pairs of counter-rotating rollers provided with blades and between which the sheet-like elements 1 to be cut are fed.

[0038] Advantageously, the cutting step is executed by means of the aforesaid cutting apparatus 3 and comprises, advantageously, at least one cutting operation, in which the blades 6 of the cutting device 5 cut, preferably in a clear/sharp manner, the sheet-like element 1.

[0039] In this manner, preferably, the cutting operation allows cutting, in a clear/sharp manner, the sheet-like elements 1, obtaining cut-outs 2 with edges well-defined and not torn. This, in particular, allows obtaining the cut-outs 2 without producing significant quantities of working dust.

[0040] Advantageously, the cutting step can also provide for repeating, multiple times, the aforesaid cutting operation in order to obtain cut-outs 2 of increasingly small dimensions with each repetition, possibly with different cutting devices 5 adapted to produce cut-outs 2 of different dimensions.

[0041] After the cutting step, the present process also comprises a mixing step, in which the plurality of cut-outs 2 is placed within a container 8 and a glue 9 is added to the plurality of cut-outs 2 in the container 8 in order to obtain at least one mixed product 10. Suitably, the aforesaid glue 9 is in the liquid state or semi-liquid/viscous state and is advantageously poured into the container 8 before or after the insertion of the cut-outs 2.

[0042] Advantageously, the mixing step occurs by means of a mixer 11 adapted to mix the cut-outs 2 with the glue 9, so as to amalgamate in a substantially uniform manner the cut-outs 2 within the glue 9 itself.

[0043] Preferably, with reference to the example of figure 3, the mixer 11 comprises at least one mixing blade 12 which is placed within the container 8 and is actuatable, advantageously in a motorized manner, to rotate in order to mix the mixture constituted by the glue 9 and by the cut-outs 2.

[0044] In particular, the container 8 is itself a component of the mixer 11.

[0045] Preferably, the cut-outs 2 obtained following the aforesaid cutting step each have maximum dimension substantially comprised between 1 mm and 30 mm. Such dimensions, in particular, facilitate the obtainment, following the mixing step, of a substantially uniform distribution of the cut-outs 2 in the glue 9.

[0046] After the mixing step, the present process comprises a pressing step, in which the mixed product 10 is pressed in order to obtain a pressed semifinished product 13. Advantageously, in such pressing step, the mixed product 10 is positioned in at least one mold 14, in which the mixed product 10 is pressed.

[0047] In accordance with a particular embodiment, the mixed product 10 is extracted outside the container 8 and poured (preferably directly) in the mold 14 in which the pressing step is executed, as in the example of figure 4.

[0048] In accordance with a different embodiment, the pressing step is attained directly within the container 8, which advantageously defines part of the mold 14.

[0049] Advantageously, the pressing step is carried out when the mixed product 10 is situated in a semiliquid state, in a manner such that it is more easily adapted to the form of the aforesaid mold 14.

[0050] Advantageously, the pressing step is obtained with one or more presses actuatable to act under pressure on the mixed product 10. In particular, such presses constitute part of the mold 14 itself.

[0051] For example, with reference to the example of figure 4, the mold 14 comprises a base 17 (possibly hollow) on which the mixed product 10 is placed and at least one upper press 15 actuatable to be moved towards such base 17 in order to compress the mixed product 10 between the latter and the upper press 15 itself.

[0052] After the pressing step, the present process also comprises a solidification step, in which the glue 9 of the pressed semifinished product 13 at least partially solidifies in order to obtain a final solid product 18.

[0053] Preferably, the solidification step occurs by letting the pressed semifinished product 13 dry under air for a specific time period, in particular at ambient temperature.

[0054] During this step, part of the humidity present both on the surface and within the semifinished product 13 is advantageously eliminated by means of evaporation thereof. In accordance with the idea underlying the present invention, the glue 9 used in the mixing step comprises at least one natural resin and the aforesaid glue 9 contains a fraction based on components of natural origin greater than 70% with respect to the weight of the dry residue of the glue 9.

[0055] More in detail, the aforesaid components of natural origin are present at least in the natural resin of the glue 9, but they can also be present within the remaining part of the glue 9. In other words, the components of natural origin can be present within the entire glue 9 or only in the natural resin that forms the glue 9 itself.

[0056] In addition, the process comprises an admixing step, in which the glue 9 is admixed with at least one biocide.

[0057] In this manner, in particular, the solid product 18 obtained with the present process is composed with components with low environmental impact (in particular with low chrome and formaldehyde content).

[0058] Advantageously, the presence of at least one natural resin in the glue 9 allows increasing the percentage of natural products of the present process and increasing the softness of the finished products.

[0059] In addition, the natural resin used in the glue 9 advantageously allows attaining an ecosustainable process, which reduces the percentage of synthetic resins used. In particular, also the discard residues of the glue 9 will be easily disposable without risking environmental pollution.

[0060] In addition, the present process comprises a step of wetting the cut-outs 2, which is executed before the mixing step, and preferably after the cutting step.

[0061] In such wetting step, the cut-outs 2 are wetted at least with water.

[0062] In general, in the wetting step, the cut-outs 2 are wetted with a bathing liquid comprising water, and possibly further additives in solution.

[0063] Preferably, the wetting step can be obtained via application of nebulized water to the cut-outs 2, or via immersion in a bath.

[0064] Advantageously, such wetting step allows improving the adhesion of the cut-outs 2 bathed with the glue 9 containing natural resin employed in the mixing step. Indeed, it was surprisingly found that the bathed condition of the cut-outs 2 allows the glue 9 with natural resin to be effectively bonded to such cut-outs 2, ensuring good mechanical strength of the solid product 18 obtained with the present process. Hence this allows obtaining a solid product 18 which has optimal characteristics of ecosustainability (since attained with products of natural derivation) and simultaneously has mechanical characteristics capable of rendering it suitable for many different applications.

[0065] Advantageously, the natural resin of the glue 9 is of animal or plant or fossil origin.

[0066] In particular, as is known, by resins of plant origin, it is intended resins that are secreted by specific plants (directly from the surface or from suitable internal structures) both spontaneously and following incisions made on the trunk.

[0067] By resins of fossil origin, it is intended resins of plant origin, deriving from plants that are no longer living, and which have undergone a process of fossilization.

[0068] By resins of animal origin, for example lac, it is intended resins obtained from secretions of insects.

[0069] Advantageously, the glue 9 also comprises multiple natural resins, of one or more of the above-described types.

[0070] Advantageously, the natural resin of the glue 9 is a polydiene natural resin.

[0071] Advantageously, the glue 9 also comprises at least one polyurethane resin, which advantageously confers to the solid product 18 a small linear shrinkage, a quick demolding, a high impact and abrasion resistance, size stability and an optimal surface finish.

[0072] In addition, the polyurethane resin has an optimal resistance at high temperatures and a low dielectric constant.

[0073] Advantageously, the polyurethane resin of the glue 9 is an aliphatic polyether polyurethane resin.

[0074] In particular, such resin of the glue 9 confers to the solid product 18 an excellent resistance to weathering agents, wear resistance, chemical resistance, solvent resistance, stain resistance, water resistance, heat stability, and improved covering characteristics. As mentioned above, the glue 9 contains a fraction based on components of natural origin greater than 70% with respect to the weight of the dry residue of the glue 9, and in particular between 80% and 85%.

[0075] In general, the dry residue is the sum of the weight of the non-volatile components present in the glue 9, expressed as percentage of the total weight of the glue 9.

[0076] By components of natural origin, it is intended polymer compounds starting from natural and/or organic monomers.

[0077] Advantageously, the aforesaid polyurethane resin is obtained from raw materials of natural origin and belongs to the aforesaid fraction of components of natural origin of the glue 9.

[0078] Advantageously, the high percentage of components of natural origin present in the glue 9 determines a greater softness of the mixed product 10 at the end of the mixing step. The high percentage of components of natural origin renders the process advantageously ecosustainable and with low environmental impact.

[0079] Advantageously, during the mixing step, the cut-outs 2 and the glue 9 are mechanically mixed together, preferably at a temperature comprised between 15° C and 30° C, for example at ambient temperature.

[0080] Advantageously, the mixing step is executed for a time interval comprised between 5 and 30 minutes, e.g. for about 10 minutes.

[0081] In this manner, the glue 9 is mixed with the cut-outs 2, obtaining at least one mixed product 10 which is advantageously sufficiently amalgamated.

[0082] As mentioned above, the process comprises an admixing step, in which the glue 9 is admixed with at least one biocide, which is in particular a biocide based on phenols.

[0083] Advantageously, the biocide contains 4-chloro-3-methylphenol and preferably also contains o-phenylphenol. Preferably, the aforesaid biocide comprises both 4-chloro-3-methylphenol and o-phenylphenol, in particular in a quantity greater than 30% with respect to the total weight of the biocide.

[0084] This allows preventing the onset, in the solid product 18, of bacteria, fungi, molds and other organisms and/or microorganisms which could compromise the functionality and the duration of the finished product obtained from the present process.

[0085] Preferably, the biocide is admixed with the glue 9 in a percentage that varies between 0.05% and 1% with respect to the total mass of the glue 9.

[0086] Advantageously, the biocide is admixed with the glue 9 before the mixing step, so as to facilitate the uniform distribution thereof within the glue 9 itself.

[0087] Otherwise, the biocide is admixed with the glue 9 during the mixing step, in a manner such that it is at least partially mixed with the cut-outs 2.

[0088] Advantageously, after the solidification step, the process comprises a dehumidification step, in which the solid product 18 is placed in a dehumidification chamber in order to remove at least part of residual humidity present in the solid product 18.

[0089] For example, such dehumidification step is obtained by means of a dehumidifier, per se of known type, which is adapted to remove humidity from the aforesaid dehumidification chamber so as to extract the humidity also from the solid product 18 placed at its interior.

[0090] Advantageously, the dehumidification step has the object of removing, from the solid product 18, most of the humidity present in the cut-outs 2 following the wetting step, so as to bring the humidity of the solid product 18 below a quantity that prevents the onset of bacteria, fungi, molds and other organisms and/or microorganisms which could compromise the functionality and the duration of the solid product 18 obtained from the present process.

[0091] Advantageously, in the mixing step the glue 9 is added in the container 8 in a quantity comprised between 60% and 120% with respect to the weight of the cut-outs 2, and preferably between 80% and 100%, as a function for example of the hide type used.

[0092] Advantageously, the solid product 18 obtained by means of the present process is made in sheet form, or panel form (as in the example illustrated in figure 5). Of course, the solid product 18 can also be shaped with other forms, as a function of the use or application destination.

[0093] As stated above, the solid product 18 can be arranged for use in multiple fields.

[0094] In particular, the attained solid product 18 can be used as starting product in order to obtain finished products. For example, in the clothing field the solid product 18, in particular in sheet form, is usable for making clothing garments or parts thereof, possibly coupled to other elements. In particular, the product can be used for making parts of clothes, such as jackets or gloves, or in the footwear field, e.g. for making the upper or insoles (possibly coupled with other layers) of footwear.

[0095] In addition, the solid product 18 can have application in the leather field, in particular for making bags, belts, wallets, etc.

[0096] Advantageously, the solid product 18 can be used for making stationary products, such as cards, document holders, restaurant menus, etc., or even products of further fields such as glass-holders, coverings for bottles, etc.

[0097] Advantageously, the solid product 18 can be used in the automobile field for making for example covers for the interior of automobiles (such as the dashboard or the upholstery).

[0098] In addition, the solid product 18, in particular attained in the form of a panel, is suitable for being employed in the construction field, in particular as insulating panel, and can for example be interposed between plasterboard panels in order to obtain a wall. In addition, the solid product 18 can be used as tile (both for wall covering and for floor), possibly rigidly coupled with a ceramic support. In addition, the product 18, suitably shaped, can constitute further construction elements, such as roof tiles, shower plates, insulation sheaths, etc., possibly subjected to treatments in order to render them adapted (e.g. more impermeable) for the specific application. Advantageously, the solid product 18, in particular in sheet form, can be used for covering walls, for example in substitution of wallpaper.

[0099] In addition, the solid product 18 can advantageously have use in the furniture/interior design field; in particular, the solid product 18, attained in the form of a panel, can be stably interposed between a pair of wood panels, obtaining a wall of a building. Advantageously, the solid product 18, in particular in sheet form, can be used for covering furniture pieces, such as armchairs, couches, seats, etc.

[0100] The invention thus conceived therefore attains the pre-established objects.

Claims

1. Process for making a solid product (18) starting from hides, comprising:

- a step of arranging at least one sheet-like element (1) made of hides;

- a cutting step, in which said sheet-like element (1) is cut into a plurality of cut-outs (2);

- a mixing step, in which at least said plurality of cut-outs (2) is placed within a container (8) and a glue (9) is added to the plurality of cut-outs (2) in said container (8) in order to obtain at least one mixed product (10);

- a pressing step, in which said mixed product (10) is pressed in order to obtain a pressed semifinished product (13);

- a solidification step, in which the glue (9) of said pressed semifinished product (13) at least partially solidifies in order to obtain said solid product (18);

- a step of wetting said cut-outs (2), executed before said mixing step, in which said cut-outs (2) are wetted at least with water;

said process being characterized in that said glue (9) comprises at least one natural resin;

wherein said glue (9) contains a fraction based on components of natural origin greater than 70% with respect to the weight of the dry residue of said glue (9);

wherein said process comprises an admixing step, in which said glue (9) is admixed with at least one biocide.

2. Process according to claim 1, characterized in that said glue (9) also comprises at least one polyurethane resin.

3. Process according to claim 2, characterized in that the polyurethane resin of said glue (9) is an aliphatic polyether polyurethane resin.

4. Process according to claim 2 or 3, characterized in that the natural resin of said glue (9) is a polydiene natural resin.

5. Process according to any one of the preceding claims, characterized in that, in said mixing step, said cut-outs (2) and said glue (9) are mechanically mixed together, at a temperature comprised between 15° C and 30° C.

6. Process according to any one of the preceding claims, characterized in that said mixing step is executed for a time interval comprised between 5 and 30 minutes.

7. Process according to any one of the preceding claims, characterized in that said at least one biocide is based on phenols.

8. Process according to any one of the preceding claims, characterized in that the step of admixing said at least one biocide is executed before said mixing step or during said mixing step.

9. Process according to any one of the preceding claims, characterized in that said at least one biocide is admixed with said glue (9) in a percentage that varies between the 0.05% and 1% with respect to the total mass of said glue (9).

10. Process according to any one of the preceding claims, characterized in that it comprises a dehumidification step, in which said solid product (18) is placed in a dehumidification chamber in order to remove at least part of residual humidity present in said solid product (18).

11. Process according to any one of the preceding claims, characterized in that in the mixing step, said glue (9) is added in said container (8) in a quantity comprised between 60% and 120% with respect to the weight of said cut-outs (2).

Drawing