Reinforced, reusable, flexible hose

Abstract

The reinforced flexible hose for transporting fluids comprises at least one first load-bearing layer (10) made of a first polymeric material, at least one second covering layer (20) made of a second polymeric material and arranged on the outside of the at least one first load-bearing layer (10), and at least one reinforcing layer (30) made of a third polymeric material and interposed between the at least one first and second layers (10, 20). The first and second polymeric materials are thermoplastic elastomers, and the third polymeric material is a thermoplastic polymeric material. As a result of the compatibility of the first, second and third polymeric materials with each other, the flexible hose can be ground without separation between the at least one first and second layers (10, 20) and the at least one reinforcing layer (30) to obtain a ground mixture (60) consisting of the first, second and third polymeric materials.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible hoses, such as irrigation hoses, and more particularly to reusable reinforced flexible hoses, as well as to the pulverized mixtures obtained by pulverizing such flexible hoses, and to the method for manufacturing reinforced flexible hoses starting from such pulverized mixtures. Definitions

[0002] In this specification, the expression "fiber reinforcement layer" or "reinforcement layer" or its derivatives are used to indicate a layer consisting of at least one fiber yarn disposed on a layer below. The "reinforcement layer" is disposed on the strength layer so as to leave generally square, rectangular, or diamond-shaped portions.

[0003] In this document, the expression "crosshatched fiber layer" or "crosshatch layer" or "crosshatching", or its derivatives, are used to indicate a layer consisting of at least two yarns or groups of yarns that are inclined in opposite directions, overlapping each other but not connected, and wound spirally around the strength layer. Thus, crosshatching consists of two or more overlapping spirals.

[0004] In this specification, the expression "compatible material" or its derivatives are used to indicate materials having mutual chemical and / or physical compatibility, i.e., materials that, when bonded, result in a joint suitable for withstanding the transmission of tensile or shear forces through the contact surface. Therefore, the greatest compatibility is observed in the same material or materials having the same base material of the same main component.

[0005] In this specification, the expression "base material" of a polymeric material or its derivatives are used to indicate a polymer that can give the molecular structure of the final product.

[0006] In this document, the expression "polymeric material" or its derivatives are used to indicate both a single polymer and mixtures of a plurality of polymers (e.g., formulations or compounds). [Background technology]

[0007] Reinforced flexible hoses are known to essentially consist of two parts: a tubular component made of polymer material and a component made of threads that form the reinforcing material. Generally, the tubular component consists of two or more layers made of polymer material with reinforcing threads placed between them.

[0008] Typically, reinforcing threads are made from materials that are not compatible (mixed) with the polymer materials that form the polymer components. Furthermore, the materials forming the layers of polymer components are not necessarily compatible with each other, although compatibility is a necessary condition for the reusability of flexible hoses.

[0009] However, even if the polymer component is made of compatible material, if there is incompatibility between the polymer component and the thread material, it will be necessary to separate the two components for the purpose of hose reuse.

[0010] This process is long, costly, and difficult to carry out, making the reuse of flexible hoses economically inconvenient, even if it exists at an industrial level as a form of production waste recycling.

[0011] Furthermore, it is essentially impossible to completely separate the threads from the tubular components of a hose, which leads to the fact that recycled material granules always contain a more or less higher percentage of impurities. Obviously, this negatively affects the mechanical properties of hoses made from this material. [Overview of the project] [Problems that the invention aims to solve]

[0012] The objective of the present invention is to overcome the drawbacks outlined above by providing a highly effective and relatively cost-effective reinforced flexible hose.

[0013] A further object of the present invention is to provide an easily reusable, reinforced, flexible hose.

[0014] A further object of the present invention is to provide a reinforced flexible hose that, when properly reused, yields a novel flexible tube having mechanical properties comparable to the original.

[0015] As described and / or claimed and / or illustrated herein, these and other objectives, which will become more apparent below, are achieved by reinforced flexible hoses, as well as by pulverized mixtures and methods for producing the same. [Means for solving the problem]

[0016] Therefore, the present invention relates to a reinforced flexible hose for transporting fluids, A first load-bearing layer made of a first polymer material, A second coating layer made of a second polymer material and positioned outside at least one first load-bearing layer, It comprises a third polymer material and at least one reinforcing layer interposed between at least one first and second layer, The first and second polymer materials are thermoplastic elastomers, and the third polymer material is thermoplastic. This invention relates to a flexible hose in which first, second, and third polymer materials are compatible with each other (mixable, miscible).

[0017] In this way, a flexible hose can be crushed without separating the load-bearing layer, the coating layer, and the reinforcing layer in order to obtain a crushed mixture consisting of the first, second, and third polymer materials.

[0018] Suitablely, the pulverized mixture may have a Shore A hardness measured according to ISO 868:2003 that is higher than the weighted average of the Shore A hardnesses of the first and second polymer materials measured according to ISO 868:2003 (preferably 8 ShA to 20 ShA, more preferably 10 ShA to 18 ShA).

[0019] Advantageously, the first and / or second polymer material may be a compound whose composition includes a third polymer material.

[0020] For example, the thermoplastic elastomers forming the first and second polymer materials may be a TPV containing EDPM and polypropylene (e.g., SANTOPRENE® commercially available from EXXONMOBIL Corporation), or a TPE-S containing SEBS and polypropylene (e.g., Nilflex SH commercially available from Taro Plast SpA), while the third thermoplastic polymer material may be polypropylene.

[0021] On the other hand, a ground mixture obtained by grinding the above flexible hose may be provided, and the mixture preferably has a plurality of polygonal pieces having a larger diagonal between 3 mm and 25 mm.

[0022] On the other hand, a method for manufacturing a reinforced flexible hose for transporting a fluid starting from the ground mixture according to claim 9, extruding a fourth polymer material comprising or consisting of the ground mixture to obtain at least one first layer, preferably a strength layer; preferably, a method may be provided that includes the step of making at least one reinforcing layer made of a fifth polymer material compatible with the fourth polymer material on top of the strength layer.

[0023] Suitably, the fourth polymer material may include the ground mixture and at least one sixth polymer material compatible with the ground mixture in a weight ratio between 1:99 and 10:90.

[0024] Advantageously, the ground mixture may be obtained starting from the production waste of the hose manufacturing line from which it is derived. The dependent claims define advantageous embodiments of the present invention.

[0025] Further features and advantages of the present invention will become more apparent from the following detailed description of some preferred but non-exclusive embodiments of the present invention, which are shown by way of non-limiting example and reference to the accompanying drawings.

Brief Description of the Drawings

[0026] [Figure 1] It is a schematic view of a production line of a reinforced flexible hose 1.

Mode for Carrying Out the Invention

[0027] Referring to the above-mentioned drawings, in this specification, a flexible gardening hose 1 for watering flowers, plants, etc. will be described. Such a hose is suitable for being connected to a domestic water main pipe by a special joint in a method known per se, and as a result, the hose transports drinking water from an appliance of the domestic water main pipe, such as a faucet, to a location where watering is carried out, such as a garden, flower bed, etc.

[0028] In the following, the gardening hose will always be referred to, but it is clear that the hose according to the present invention can be used for any purpose without departing from the scope of protection of the appended claims.

[0029] The hose 1 may essentially comprise one or more inner resistance layers 10, one or more outer coating layers 20, and one or more fiber reinforcement layers 30 interposed therebetween.

[0030] In the following, a three-layer hose will be referred to, but it is clear that the hose according to the present invention can have any number of layers without departing from the scope of protection of the appended claims, regardless of whether it is made of a polymer material or a reinforcing fiber.

[0031] The inner layer 10 and the outer layer 20 may be made of respective compatible polymer materials, preferably the same polymer material.

[0032] These polymer materials may be thermoplastic elastomers, such as TPV, TPE-S, TPE-O, or TPE-A.

[0033] Preferably, the materials of the inner layer 10 and the outer layer 20 may be a TPV compound having an EPDM base material consisting of, for example, a mixture of EPDM, polypropylene, and paraffin oil, or an SEBS-based TPE-S compound consisting of, for example, SEBS, polypropylene, and paraffin oil.

[0034] Appropriately, the overall Shore A hardness of the inner layer 10 and outer layer 20 materials, measured according to ISO 868:2003, may be between 60 ShA and 75 ShA in the case of the EPDM-based compounds described above, and between 35 ShA and 55 ShA in the case of the SEBS-based compounds described above.

[0035] If there is a difference in Shore A hardness between the inner layer 10 and the outer layer 20, the overall hardness may be measured from the average hardness of the two materials forming such a layer and weighted in proportion to the weight of each individual layer relative to the total weight of the layer.

[0036] Furthermore, advantageously, the overall melt-flow index of the inner layer 10 or outer layer 20 material, measured according to ISO 1133-230°C-5Kg, may be between 1 g / 10 min and 5 g / 10 min for the EPDM-based compounds described above, and the overall melt-flow index of the inner layer 10 and outer layer 20 material, measured according to ISO 1133-190°C-5Kg, may be between 5 g / 10 min and 10 g / 10 min for the SEBS-based compounds described above.

[0037] On the other hand, the reinforcing layer 30 may be made of a fibrous polymer material that is compatible with the above-mentioned material. For example, in the case of an inner layer 10 and an outer layer 20 made of TPV, TPE-S, or TPE-O, the reinforcing layer 30 may be made of polypropylene, and in the case of an inner layer 10 and an outer layer 20 made of TPE-A, the reinforcing layer 30 may be made of polyamide. Appropriately, the reinforcing layer 30 may have any configuration, such as woven or cross-hatched.

[0038] The hose 1 may be manufactured by a method known to the contrary, particularly as shown in Figure 1, by extruding a first polymer material in a first extruder 40 to obtain an inner layer 10, then obtaining a reinforcing layer on the inner layer 10 in a knitting machine, cross-hatching machine or helical forming machine 41, and then co-extruding a coating layer 20 onto the output semi-finished product in an extruder 42.

[0039] Due to the compatibility between the polymer materials described above, the flexible hose 1 may be crushed in a known type of crusher 50, such as the TRM600 commercially available from CMG Spa, without pre-separating the polymer portion of the hose, which consists of the inner layer 10, the outer layer 20, and the reinforcing layer 30.

[0040] This makes it possible to obtain a pulverized mixture 60 consisting of layers 10, 20, and 30 of materials that are compatible with each other. Preferably, the fragments may be generally polygonal, such as squares or rectangles, having a larger diagonal dm between 3 mm and 25 mm.

[0041] The Shore A hardness of the pulverized mixture 60, measured according to ISO 868:2003, may be greater than the overall Shore A hardness of the inner layer 10 and outer layer 20 materials, which is 8 ShA to 20 ShA, preferably 10 ShA to 18 ShA.

[0042] In a preferred but non-exclusive embodiment of the present invention, in the aforementioned example of an inner layer 10 and an outer layer 20 made from an EPDM-based TPV containing polypropylene, and a reinforcing layer 30 made from polypropylene, the pulverized mixture 60 contains EPDM and polypropylene, with polypropylene present in a larger quantity than the amount of polypropylene in the untreated TPV.

[0043] In this case, the weighted average of the Shore A hardness of the materials forming the inner layer 10 and the outer layer 20, measured according to ISO 868:2003, may be between 60 ShA and 75 ShA, and the Shore A hardness of the pulverized mixture 60, measured according to ISO 868:2003, may be between 70 ShA and 90 ShA.

[0044] Furthermore, in this case, the melt flow index of the pulverized mixture 60, measured according to ISO1133-230℃-5kg, may be higher than the melt flow index of the inner layer 10 and outer layer 20 materials, which ranges from 8 g / 10 min to 25 g / 10 min.

[0045] For example, the melt flow index of each of the materials of the inner layer 10 and the outer layer 20, measured according to ISO 1133-230°C-5Kg, may be between 1 g / 10 min and 5 g / 10 min, and the melt flow index of the pulverized mixture 60, measured according to ISO 1133-230°C-5Kg, may be between 10 g / 10 min and 30 g / 10 min.

[0046] In a more preferred but non-exclusive embodiment of the present invention, when the inner layer 10 and outer layer 20 are made of SEBS-based TPE-S containing polypropylene and the reinforcing layer 30 is made of polypropylene, the pulverized mixture 60 contains SEBS and polypropylene, with polypropylene present in a larger quantity than the amount of polypropylene in the untreated TPE-S.

[0047] In this case, the weighted average of the Shore A hardness of the materials forming the inner layer 10 and the outer layer 20, measured according to ISO 868:2003, may be between 35 ShA and 55 ShA, and the Shore A hardness of the pulverized mixture 60, measured according to ISO 868:2003, may be between 55 ShA and 75 ShA.

[0048] As schematically shown in Figure 1, the pulverized mixture 60 may be used as a raw material for manufacturing a novel reinforced flexible hose for transporting fluids. In some cases, for this purpose, the pulverized mixture 60 may be appropriately added by, for example, the addition of paraffin oil.

[0049] In this sense, the present invention may define a method for reusing production waste from a flexible hose manufacturing line, in which discarded flexible hoses are reused and converted into raw materials for new hoses.

[0050] In this production line, the pulverized mixture 60 is used as is, or, as shown in Figure 1, is blended with suitable untreated material 61 and then cut.

[0051] The weight ratio between the pulverized mixture 60 and the suitable untreated material 61 may be between 1:99 and 30:70. If the weight ratio exceeds this, the mechanical properties of the resulting polymer will be unsuitable for manufacturing the flexible hose of the type described above.

[0052] Given that the industrially acceptable average production waste for a flexible hose manufacturing line is up to 5%, obtaining a weight ratio in a large quantity of crushed mixture 60 would require accumulating a large amount of production waste over several business days.

[0053] This clearly requires proper management of production waste and storage space at the production site.

[0054] Therefore, preferably, the weight ratio between the pulverized mixture 60 and the suitable untreated material 61 may be between 1:99 and 10:90.

[0055] This makes it possible to reuse up to one business day's worth of production waste regularly, for example, every half-business day or at the end of a business day, without requiring the accumulation of production waste or related management.

[0056] The combination of the untreated material 61 and the pulverized mixture 60 may form a first polymer material and / or a second polymer material as shown in Figure 1, without departing from the scope of protection of the appended claims. In other words, the combination of the untreated material 61 and the pulverized mixture 60 may be used to obtain a load-bearing layer or coating layer for a hose.

[0057] In the aforementioned example where the untreated material 61 is untreated TPV, the crushed mixture 60 may be derived from the crushing of TPV hose production waste, as described above.

[0058] To repeat the above cycle in a circular economy, the novel hose may include a reinforcing layer made of a suitable material, such as polypropylene.

[0059] The aforementioned features make it possible to obtain a complete and easily reusable hose simply by inserting the hose into the crusher 60, without any prior operation to separate the reinforcing layer from the rest of the hose.

[0060] The resulting pulverized mixture may be used to manufacture new hoses. As is evident, this reduces both the cost and environmental impact associated with hose manufacturing. The present invention will become clearer in light of the following embodiments.

[0061] <Examples> Preparing the hose Four samples measuring a 10m hose were prepared using the following raw materials. Inner layer. SANTOPRENE® 201-64, marketed by EXXONMOBIL® Corporation. Outer layer. SANTOPRENE® 201-73, marketed by EXXONMOBIL® Corporation. Reinforcement layer. PP yarn 1200DN "AT" TANG C.WHITE, commercially available from Industrias Ponsa, SA.

[0062] The hose was manufactured in a known manner by extruding the inner and outer layers using an extruder of a known type, and by forming a knitted layer having a tricot-type chain stitch of the NTS(registered trademark) (Samples 3 and 4) or DCT (Samples 1 and 2) type on the inner layer using a knitting machine of a known type. The weight distribution in the four samples is as follows: (Table 1) TIFF0007883500000001.tif42144

[0063] Shore hardness measurement The overall Shore A hardness of the materials forming samples 1-4 described above was measured using an ATS FAAR Shore A type Shore hardness tester in accordance with ISO 868:2003. The overall hardness was measured by calculating the weighted average of the Shore A hardness of the inner layer (hardness ShA: 64) made with SANTOPRENE® 201-64 and the outer layer (hardness ShA: 73) made with SANTOPRENE® 201-73, both of which were clearly measured according to the above-mentioned criteria. The results are reported in the table below. (Table 2) TIFF0007883500000002.tif39144

[0064] MFI measurement The MFI of the materials forming the tubular layers of the above-mentioned samples 1-4 (SANTOPRENE® 201-64 and SANTOPRENE® 201-73) was measured using an INSTRON® CEAST Melt Flow Tester MF 30, in accordance with the ISO 1133-230℃-5Kg standard. The results are reported in the table below. (Table 3) TIFF0007883500000003.tif33144

[0065] Hose shredding Each of the four hose samples described above was inserted directly into a TRM600 crusher, commercially available from CMG Spa, and crushed without pre-separating the reinforcing layer from the polymer material. The resulting mixture fragments were then separated using a 15 mm mesh sieve.

[0066] Measurement of Shore hardness of mixtures For each of the mixtures derived from the grinding of the above-mentioned samples, the Shore A hardness was measured according to the ISO 868:2003 standard using the same Shore hardness tester as described above. The results are reported in the table below. (Table 4) TIFF0007883500000004.tif42144

[0067] Therefore, it is clear that when mixed with polymer materials, the polypropylene threads of various hose samples significantly increased the Shore A hardness of the mixture.

[0068] Measurement of MFI of a mixture For each of the mixtures derived from the grinding of the above-mentioned samples, the MFI was measured according to the ISO 1133-230°C-5kg standard using the same melt flow tester as described above. The results are reported in the table below. (Table 5) TIFF0007883500000005.tif42144

[0069] Therefore, it is clear that when mixed with polymer materials, the polypropylene threads of various hose samples significantly increased the MFI of the mixture. New hose preparation

[0070] The mixtures obtained from the four aforementioned samples were mixed with untreated SANTOPRENE® 201-64 granules in a 5:95 ratio. This mixture of untreated and crushed material was extruded to obtain the load-bearing layers of each new 10m hose sample. Each of these load-bearing layers was inserted into a knitting machine to obtain the polypropylene reinforced layer described above, and then SANTOPRENE® 201-73 was extruded onto the semi-finished product coming out of the knitting machine to obtain the coating layer. The weight distribution of the new hose samples was the same as that of samples 1-4 described above. Essentially, four hose samples similar to the starting sample were obtained from both a quality and mechanical standpoint.

[0071] Mechanical properties to weight ratio To investigate how the mechanical properties of the polymer material change as the weight ratio between the pulverized mixture and the untreated material changes, various samples consisting of SANTOPRENE® 201-73 and the above-mentioned "Sample Mixture 1" (SAMP MIX 1) were prepared in ratios ranging from 97:3 to 50:50, as reported in the table below.

[0072] For each sample, we measured Shore A hardness according to ISO 868:2003 using an ATS FAAR Shore A-type Shore hardness tester, MFI according to ISO 1133-230℃-5Kg using an INSTRON® CEAST Melt Flow Tester MF30-type melt flow tester, and tensile force according to ISO 37 / ISO 527-2-2012 using a Sun2500 model dynamometer with a 25kN load cell and a strain gauge with a maximum speed of 600 mm / min.

[0073] The tests showed a substantial decrease in the desired mechanical properties as the proportion of Sample Mix 1 (SAMP MIX 1) increased, with the greatest difference observed at 35% of the pulverized mixture.

[0074] Therefore, the maximum weight ratio between the untreated polymer and the pulverized mixture that allows for obtaining an extruded polymer suitable for producing reinforced flexible hoses is 70 to 30. (Table 6) TIFF0007883500000006.tif111170

Claims

1. A method for recycling production waste from a production line into a reinforced flexible hose, starting from production waste from the production line, by manufacturing a new, reusable, and reinforced flexible hose for transporting fluids, wherein the method is: A step of providing a pulverized mixture (60) obtained by pulverizing the production waste of the production line, wherein the flexible hose is A first load-bearing layer (10) made of a first polymer material, A second polymer material is used to form at least one second coating layer (20) located outside the at least one first load-bearing layer (10), It comprises a third polymer material and at least one reinforcing layer (30) interposed between the at least one first load-bearing layer (10) and the second coating layer (20), The first and second polymer materials are thermoplastic elastomers, and the third polymer material is a thermoplastic polymer material. As a result of the compatibility of the first, second, and third polymer materials with respect to each other, the at least one first load-bearing layer (10) and second coating layer (20) can be crushed without separation between the at least one reinforcing layer (30), and the step, The process includes the step of extruding a fourth polymer material containing the pulverized mixture (60) to obtain the at least one first load-bearing layer (10) and / or second coating layer (20) of the flexible hose, The fourth polymer material comprises the pulverized mixture (60) and at least one fifth polymer material (61) compatible therewith, wherein the fifth polymer material is an untreated thermoplastic elastomer. A method wherein the fourth polymer material has a weight ratio between the pulverized mixture (60) and the at least one fifth polymer material (61) between 1:99 and 10:

90.

2. The method according to claim 1, wherein the pulverized mixture (60) has a Shore A hardness measured according to ISO 868:2003 that is higher than the weighted average of the Shore A hardnesses measured according to ISO 868:2003 of the at least one first and second polymer material.

3. The method according to claim 2, wherein the Shore A hardness of the pulverized mixture (60), as measured according to ISO 868:2003, is greater than the weighted average of the Shore A hardnesses of the at least one first and second polymer material, which is 8 ShA to 20 ShA, preferably 10 ShA to 18 ShA.

4. The method according to claim 1, 2, or 3, wherein the first and second polymer materials are EPDM-based, the weighted average Shore A hardness of at least one of the first and second polymer materials, as measured according to ISO 868:2003, is between 60 ShA and 75 ShA, and the Shore A hardness of the pulverized mixture (60), as measured according to ISO 868:2003, is between 70 ShA and 90 ShA.

5. The method according to claim 1, 2, or 3, wherein the first and second polymer materials are SEBS-based, the weighted average Shore A hardness of at least one of the first and second polymer materials, as measured according to ISO 868:2003, is between 35 ShA and 55 ShA, and the Shore A hardness of the pulverized mixture (60), as measured according to ISO 868:2003, is between 55 ShA and 75 ShA.

6. The method according to any one of claims 1 to 4, wherein the first and second polymer materials are EPDM-based, the melt flow index of at least one of the first or second polymer materials, as measured according to ISO 1133-230°C-5Kg, is between 1 g / 10 min and 5 g / 10 min, and the melt flow index of the pulverized mixture (60), as measured according to ISO 1133-230°C-5Kg, is between 10 g / 10 min and 30 g / 10 min.

7. The method according to any one of claims 1 to 6, wherein the first polymer material and / or the second polymer material is a compound comprising the third polymer material.

8. The method according to any one of claims 1 to 7, wherein the thermoplastic elastomer is an EDPM-based TPV containing polypropylene, or an SEBS-based TPE-S containing polypropylene, and the third polymer material is polypropylene.

9. The method according to any one of claims 1 to 8, wherein the pulverized mixture has a plurality of polygonal pieces having larger diagonal lengths (dm) between 3 mm and 25 mm.

10. A reusable and reinforced flexible hose obtained by the method according to any one of claims 1 to 9.

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