Transport hose

Abstract

Provided is a transport hose having high durability. A transport hose 1 includes: a translucent outer layer 11; a translucent reinforcement layer 12 provided inside the outer layer 11; a translucent buffer layer 13 provided inside the reinforcement layer 12; and an inner surface abrasion-resistance layer 14 which is translucent and is provided inside the buffer layer 13. A reinforcement core 12a is spirally wound around on the outside of the buffer layer 13. The buffer layer 13 is colored, and the hardness of the buffer layer 13 is lower than the hardness of the inner surface abrasion-resistance layer 14.

Description

Transport Hose

[0001] The present invention relates to a transport hose used to transport solid materials such as granules and powders, and fluid materials such as liquids.

[0002] Synthetic resin transport hoses are used to transport solids such as granules and powders, and fluids such as liquids. The inner surface of such transport hoses wears over time due to contact with the transported materials, eventually leading to cracks and breakage. Therefore, the hose needs to be replaced periodically to prevent such cracks and breakage, but it is difficult to accurately predict when to replace the hose. The present applicant has proposed a transport hose in which the innermost layer constituting the abrasion-resistant layer is colored, as disclosed in Patent Documents 1 and 2. This transport hose gradually changes color depending on the degree of wear of the inner layer, allowing the degree of wear to be detected simply by visual inspection from the outside. Once the color has completely changed, it is clear that the inner layer in that area has worn away.

[0003] JP 2010-159822 A JP 2011-064305 A

[0004] However, the transport hoses of Patent Documents 1 and 2 have a colored innermost layer, which has abrasion resistance, and thus begin to change color due to wear even when the hose's abrasion resistance remains. Furthermore, at curved sections of transport hoses where the transported material repeatedly collides with the inner wall, there is a problem of accelerated wear of the inner surface of the area below the reinforcing core (localized uneven wear). This is due to the influence of the reinforcing core located on the outer layer of the inner surface layer, which results in a large difference in rigidity between the flow area without the reinforcing core and the area below the reinforcing core, and the area below the reinforcing core having higher localized inner rigidity and lower cushioning than the area without the reinforcing core. The present invention was made to solve the above problems and aims to provide a hose that is highly durable and allows users to easily recognize when it is time to replace the product.

[0005] The transport hose of the present invention is a transport hose for transporting solids or fluids, and is characterized in that it has a translucent outer layer, a translucent reinforcing layer provided inside the outer layer, a translucent buffer layer provided inside the reinforcing layer, and a translucent inner abrasion-resistant layer provided inside the buffer layer, a reinforcing core spirally wound outside the buffer layer, the buffer layer is colored, and the hardness of the buffer layer is lower than the hardness of the inner abrasion-resistant layer.

[0006] The transport hose of the present invention has a buffer layer between the reinforcing layer and the inner abrasion-resistant layer, which provides cushioning to the inner abrasion-resistant layer and enhances the abrasion resistance of the hose. Furthermore, because the buffer layer is also located between the reinforcing core and the inner abrasion-resistant layer, it can reduce the difference in stiffness between the inner abrasion-resistant layer and suppress localized uneven wear of the inner abrasion-resistant layer. This is particularly noticeable when the transport hose is curved. Furthermore, because the inner abrasion-resistant layer is provided inside the colored buffer layer, a detection function (color change) is activated when the buffer layer begins to wear, indicating when the transport hose should be replaced. In other words, the user can recognize the area where the detection function begins to be activated as the inner abrasion-resistant layer is worn out, allowing the hose's abrasion resistance to be fully utilized. Thus, the transport hose of the present invention can be used efficiently until replacement is required, resulting in a long service life.

[0007] In the transport hose of the present invention, the inner abrasion-resistant layer is preferably colorless and transparent. In this case, the time when the color of the hose first changes can be used as a guide for starting replacement. In the transport hose of the present invention, the outer layer is preferably colored a different color from the buffer layer. In this case, the change occurs from a state in which multiple colors are mixed, making the change easy to recognize.

[0008] In the transport hose of the present invention, the reinforcing layer preferably includes the reinforcing core. In this case, the reinforcing core may be provided on the resin layer, or may be substantially embedded within the resin layer. In either case, the reinforcing layer may have a spirally uneven outer shape or a uniform wall thickness. In the transport hose of the present invention, the reinforcing layer preferably includes a ground wire spirally wound near the reinforcing core. Because the ground wire is spirally wound near the reinforcing core, a sufficient gap can be secured between adjacent reinforcing cores in the axial direction of the transport hose, allowing for sufficient confirmation of color changes due to wear of the buffer layer. Furthermore, because the ground wire is provided in the reinforcing layer inside the outer layer, there is little risk of the ground wire breaking due to external wear.

[0009] In the transport hose of the present invention, preferably, the outer layer is formed with spiral irregularities. In this case, the flexibility of the transport hose is improved. In the transport hose of the present invention, preferably, the reinforcing core is provided on the outside of the outer layer. In this case, the outer shape of the transport hose has spiral irregularities, thereby improving the flexibility of the transport hose. In the transport hose of the present invention, preferably, a printed layer bearing letters or marks is provided on the outside of the buffer layer. In this case, when the detection function is exerted due to wear of the buffer layer, the detection function can be recognized not only by a color change but also by letters or marks that emerge from the outside of the transport hose. The printed layer is preferably the same color as the buffer layer, but the color is not particularly limited as long as, when the buffer layer is removed due to wear, the letters or marks emerge more clearly than before the buffer layer was worn.

[0010] The transport hose of the present invention has a buffer layer provided in a predetermined position, which provides high abrasion resistance and suppresses uneven localized wear, resulting in high durability. Furthermore, because the buffer layer is colored, when a color change occurs in a part of the hose, i.e., when the detection function is activated, it is known that the inner abrasion-resistant layer in that part has worn away. This indicates when to start replacing the transport hose, allowing the transport hose to be used efficiently until replacement is required.

[0011] Figure 1a is a side cross-sectional view showing a first embodiment of a transport hose of the present invention, and Figure 1b is a partially enlarged view thereof. Figure 1b is a side cross-sectional view showing a second embodiment of a transport hose of the present invention. Figure 4a to Figure 4c are side cross-sectional views showing portions of fourth to sixth embodiments of a transport hose of the present invention, respectively. Figures 5a to 5c are side cross-sectional views showing portions of seventh to ninth embodiments of a transport hose of the present invention, respectively. Figures 6a to 6d are photographs showing the results of a wear test.

[0012] Next, an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiment.

[0013] "Transport hose 1" The transport hose 1 in Fig. 1 has an outer layer 11, a reinforcing layer 12 provided on the inner side thereof, a buffer layer 13 provided on the inner side of the reinforcing layer 12, and an inner abrasion-resistant layer 14 provided on the inner side of the buffer layer 13. The inner abrasion-resistant layer 14 forms the inner wall of the transport hose 1. A reinforcing core 12a is provided in the reinforcing layer 12. The transport hose 1 is a flexible hose for transporting solid materials such as granules and powders, and fluid materials such as liquids.

[0014] The outer layer 11 is made of a translucent soft synthetic resin, preferably a colored translucent soft synthetic resin, and particularly preferably a colored transparent soft synthetic resin. For example, it can be obtained by mixing a pigment into a translucent soft synthetic resin or a transparent soft synthetic resin. Examples of soft synthetic resins used for the outer layer 11 include translucent synthetic resins such as vinyl chloride resin, olefin-based resin, and urethane-based resin, with vinyl chloride resin being particularly preferred. The color of the outer layer 11 is not particularly limited, but a high brightness is preferred. This makes it easier to distinguish the colors of the inner layers from the outer layer 11. For example, a yellowish color is preferred. The pigment used for the outer layer 11 is not particularly limited, but examples of yellow pigments include yellow organic pigments, yellow inorganic pigments, and yellow natural dyes, particularly condensed disazo yellow organic pigments. The hardness of the outer layer 11 is not particularly limited, but is preferably at least lower than the hardness of the inner wear-resistant layer 14. For example, the hardness of the outer layer 11 is 70 or less, preferably 68 or less, particularly preferably 65 or less, in Shore A hardness, and 50 or more, preferably 55 or more, particularly preferably 57 or more.

[0015] The outer layer 11 has spiral irregularities along the reinforcing core 12a of the reinforcing layer 12, which will be described later. Specifically, the irregularities are formed along the reinforcing core 12a and along the resin layer 12b. The transport hose 1 tends to be thicker than conventional transport hoses (such as the transport hose of Patent Document 2) due to the buffer layer 13. However, the irregularities in the outer layer 11 provide the transport hose 1 with flexibility. As shown in FIG. 1b, the height H of the concave portions of the outer layer 11 is 40% or less, preferably 30% or less, particularly preferably 25% or less, and most preferably 20% or less, and 10% or more, of the wall thickness T of the transport hose 1 (thickness from the inner surface to the convex portions). The wall thickness T1 of the outer layer 11 is 5% or more, preferably 8% or more, and particularly preferably 10% or more, and 20% or less, of the wall thickness T of the transport hose 1. The wall thickness T of the transport hose 1 is, for example, 4.3 mm to 13.4 mm. The thickness T1 of the outer layer 11 is, for example, 0.5 mm to 2.0 mm.

[0016] The reinforcing layer 12 includes reinforcing cores 12a arranged in a spiral pattern at intervals. More specifically, the reinforcing cores 12a are embedded in a resin layer 12b. The surface of the reinforcing layer 12 has a spirally uneven surface.

[0017] The reinforcing core 12a is made of a hard synthetic resin, preferably a translucent hard synthetic resin. Examples of the hard synthetic resin used for the reinforcing core 12a include translucent synthetic resins such as vinyl chloride resin, olefin resin, and urethane resin, with hard vinyl chloride resin being particularly preferred. Examples include synthetic resins with a Shore D hardness of 75 or more, preferably 78 or more, and 90 or less, preferably 86 or less. The reinforcing core 12a may be colored, but is preferably colorless. The cross-sectional shape of the reinforcing core 12a is not particularly limited, but is preferably circular or elliptical.

[0018] The resin layer 12b is made of a translucent soft synthetic resin, preferably a colorless and transparent soft synthetic resin. Examples of the soft synthetic resin used for the resin layer 12b include translucent synthetic resins such as vinyl chloride resin, olefin-based resin, and urethane-based resin, with vinyl chloride resin being particularly preferred. The resin layer 12b is preferably substantially the same as the synthetic resin of the outer layer 11. The hardness of the resin layer 12b is not particularly limited, but is preferably lower than the hardness of the inner abrasion-resistant layer 14, and is particularly preferably the same as the hardness of the outer layer 11. For example, the Shore A hardness is 70 or less, preferably 68 or less, particularly preferably 65 or less, 50 or more, preferably 55 or more, and particularly preferably 57 or more. As mentioned above, the reinforcing layer 12 is preferably colorless and transparent. However, if the reinforcing layer 12 (reinforcing core 12a and / or resin layer 12b) is colored, it is preferable to color it lower in brightness than the outer layer and higher in brightness than the inner layer.

[0019] The buffer layer 13 is made of a colored, translucent soft synthetic resin, preferably a colored, transparent, soft synthetic resin. Such a material can be obtained, for example, by mixing a pigment into a translucent soft synthetic resin, or by mixing a pigment into a transparent, soft synthetic resin. Examples of soft synthetic resins used for the buffer layer 13 include translucent synthetic resins such as vinyl chloride resin, olefin-based resin, and urethane-based resin, with vinyl chloride resin being particularly preferred. The color of the buffer layer 13 is not particularly limited as long as it is different from the color of the outer layer 11, but a color with a lower brightness than that of the outer layer 11 is preferred. For example, if the outer layer 11 is yellow, the buffer layer 13 is preferably blue or red. This allows for a clear color change that occurs as the buffer layer 13 wears away from the state in which the outer layer 11 and the buffer layer 13 are stacked. Specifically, the hardness of the colored buffer layer 13 is 70 or less, preferably 68 or less, particularly preferably 66 or less, and most preferably 64 or less on the Shure A scale, and 50 or more, preferably 55 or more, and particularly preferably 56 or more. The hardness of the buffer layer 13 is preferably less than that of the inner abrasion-resistant layer 14 described below, and particularly less than that of the resin layer 12b of the outer layer 11 and the reinforcing layer 12. The thickness T2 of the buffer layer 13 (see FIG. 1b) is 5% or more, preferably 8% or more, particularly preferably 10% or more, and 20% or less of the thickness T (thickness of the inner surface and the convex portion) of the transport hose 1. Alternatively, the thickness T2 of the buffer layer 13 is 50% or more, preferably 60% or more, particularly preferably 65% ​​or more, and 100% or less of the thickness T3 of the inner abrasion-resistant layer 14 described below. If the buffer layer 13 is too thin, localized rigid regions may occur in the inner abrasion-resistant layer 14. On the other hand, if the buffer layer 13 is too thick, the overall thickness of the hose increases, resulting in reduced flexibility. The thickness T2 of the buffer layer 13 is, for example, 0.5 mm to 2.0 mm.

[0020] The inner wear-resistant layer 14 is made of a translucent soft synthetic resin, preferably a colorless and transparent synthetic resin. Examples of soft synthetic resins used for the inner wear-resistant layer 14 include translucent synthetic resins such as urethane-based resins, vinyl chloride resins, and olefin-based resins, with urethane-based resins being particularly preferred. The hardness of the inner wear-resistant layer 14 is, in Shure A hardness, 65 or more, preferably 69 or more, particularly preferably 70 or more, and most preferably 71 or more, and 90 or less, preferably 85 or less, particularly preferably 80 or less, and most preferably 79 or less. The thickness T3 (see FIG. 1b) of the inner wear-resistant layer 14 is 5% or more, preferably 8% or more, and particularly preferably 10% or more and 20% or less of the thickness T (thickness of the inner surface and the protruding portion) of the transportation hose 1. Specific thicknesses of the inner wear-resistant layer 14 include, for example, 0.5 mm to 2.0 mm. Although the inner wear-resistant layer 14 is shown as a single layer here, the inner wear-resistant layer 14 may be composed of two or more resin layers.

[0021] "Method for manufacturing transport hose 1" Such a transport hose 1 can be formed by extruding a four-layer strip formed by laminating an outer layer 11, a reinforcing layer 12 (a resin layer 12b in which a reinforcing core 12a is embedded), a buffer layer 13, and an inner abrasion-resistant layer 14, and then winding the extrusion. However, the manufacturing method is not limited thereto, and a single-layer or any multi-layer strip may be extruded and then wound so as to overlap one another.

[0022] "Functions and Effects of the Transport Hose 1" The transport hose 1 has the buffer layer 13 disposed between the inner wear-resistant layer 14 and the reinforcing layer 12, thereby providing cushioning to the inner wear-resistant layer 14 and enhancing the wear resistance of the inner wear-resistant layer 14. Furthermore, the buffer layer 13 is also located between the inner wear-resistant layer 14 and the reinforcing core 12a, thereby reducing the rigidity difference in the inner wear-resistant layer 14 and suppressing localized uneven wear of the inner wear-resistant layer 14. This effect is particularly pronounced when the transport hose 1 is curved. Furthermore, the buffer layer 13 of the transport hose 1 is colored, so that a color change in a portion of the hose, i.e., when the detection function is activated, indicates that the inner wear-resistant layer 14 in that portion has worn away. This indicates when to start replacing the transport hose, allowing the transport hose 1 to be used efficiently until replacement is required.

[0023] "Transport hose 2" The transport hose 2 of Figure 2 has an outer layer 21, a reinforcing layer 22 provided on the inner side thereof, a buffer layer 23 provided on the inner side of the reinforcing layer 22, and an inner wear-resistant layer 24 provided on the inner side of the buffer layer 23, with a reinforcing core 25 provided on the outer side of the outer layer 21. The transport hose 2 also has the inner wear-resistant layer 24 as its inner wall. The transport hose 2 differs from the transport hose 1 of Figure 1 in that the reinforcing core 25 is provided on the outer side of the outer layer 21, and the reinforcing layer 22 is made of a material in which reinforcing fibers are embedded. Otherwise, the outer layer 21, the buffer layer 23, and the inner wear-resistant layer 24 are substantially the same as the outer layer 11, the buffer layer 13, and the inner wear-resistant layer 14 of the transport hose 1 of Figure 1. It is preferable that the material of the reinforcing core 25 be colored compared to the reinforcing core 12a of Figure 1, but they are substantially the same.

[0024] The reinforcing layer 22 is formed by embedding mesh-shaped synthetic resin fibers in a synthetic resin layer. Specifically, it is formed by winding a mesh-shaped synthetic resin fiber on the buffer layer 23 and then spirally winding a heated synthetic resin strip on top of that. Alternatively, a first strip, a synthetic resin fiber mesh, and a second strip may be provided in this order, with the synthetic resin fiber sandwiched between the two strips. The strip is made of a translucent soft synthetic resin, preferably a colorless and transparent soft synthetic resin. Examples of such soft synthetic resins include translucent synthetic resins such as vinyl chloride resin, olefin-based resin, and urethane-based resin, with vinyl chloride resin being particularly preferred. The reinforcing layer 22 is preferably made of substantially the same synthetic resin as the outer layer 21. The Shore A hardness of the strip (without mesh) is, for example, 70 or less, preferably 68 or less, particularly preferably 65 or less, and 50 or more, preferably 55 or more, and particularly preferably 57 or more. The synthetic resin fiber is not particularly limited, but examples thereof include polyester twisted yarn. Since the mesh is formed, the synthetic resin fiber does not need to be translucent. Embedding the synthetic resin fiber in the reinforcing layer 22 provides strength while maintaining the flexibility required for a hose used to transport fluids. In particular, strength is provided when the internal pressure of the hose increases.

[0025] Like the transport hose 1, the transport hose 2 has a buffer layer 23 provided between the inner wear-resistant layer 24 and the reinforcing layer 22, which provides high wear resistance, and is provided between the inner wear-resistant layer 24 and the reinforcing core 25, which prevents localized uneven wear. Furthermore, the colored buffer layer 23 allows the transport hose 2 to be used efficiently until replacement. Furthermore, since the reinforcing core 25 is provided on the surface, the transport hose 2 is more flexible than the transport hose 1 and has good slipperiness when in contact with the ground (particularly the floor). Furthermore, it is easy to reduce the weight.

[0026] "Transport Hose 3" The transport hose 3 of Figure 3 has an outer layer 31, a reinforcing layer 32, a buffer layer 33, and an inner wear-resistant layer 34, similar to the transport hose 1 of Figure 1, and the reinforcing layer 32 is provided with a reinforcing core 32a. The transport hose 3 differs from the transport hose 1 in that the outer layer 31 and the buffer layer 33 have flat cylindrical shapes on the inside and outside. Specifically, the reinforcing core 32a is substantially embedded in the resin layer 32b of the reinforcing layer 32, and the reinforcing layer 32 has a flat cylindrical shape with a uniform thickness. The outer layer 31 is provided on the outside of the reinforcing layer 32. The rest of the configuration is substantially the same as the transport hose 1 of Figure 1. The transport hose 3 is slightly less flexible than the transport hose 1. However, if it is routed in a location with few curves, it has high wear resistance, can suppress localized uneven wear, and can be used efficiently until it needs to be replaced, similar to the transport hose 1.

[0027] The transport hoses 4A to 4C of Figures 4a to 4c have an earth wire 45 wound spirally near the reinforcing core 42a.

[0028] The transport hose 4A in Fig. 4a is the transport hose 1 in Fig. 1 equipped with an antistatic ground wire 45. Specifically, the transport hose 4A has an outer layer 41 with a spirally irregular surface, a reinforcing layer 42 with a reinforcing core 42a, a buffer layer 43, and an inner wear-resistant layer 44. The ground wire 45 is spirally wound around the reinforcing core 42a within the resin layer 42b of the reinforcing layer 42. The outer layer 41, reinforcing layer 42, buffer layer 43, inner wear-resistant layer 44, and reinforcing core 42a of the transport hose 4A are substantially the same as those of the transport hose 1 in Fig. 1. The ground wire 45 is spirally wound within the reinforcing layer 42 at the same pitch as the reinforcing core 42a and is located outside the curved portion 42a2 extending downward from the top 42a1 of the reinforcing core 42a, i.e., in the gap between the reinforcing core 42a and the outer layer 41. In other words, the ground wire 45 is arranged so that at least a portion of its cross-sectional area (the width of the ground wire) when projected perpendicularly in the hose axial direction overlaps with the cross-sectional area of ​​the reinforcing core 42a when projected perpendicularly in the hose axial direction. In the transport hose 4A shown in FIG. 4a, the ground wire 45 is arranged axially forward of the top apex 42a1 of the reinforcing core 42a, while in the transport hose 4B shown in FIG. 4b, the ground wire 45 is arranged axially rearward of the top apex 42a1 of the reinforcing core 42a. By arranging the ground wires 45 at equal intervals within the reinforcing layer 42 and near the reinforcing core 42a, the ground wires 45 are less noticeable when the transport hose 4A is visually inspected because they overlap with nearby reinforcing cores 42a. Therefore, when the detection function is activated, a color change can be clearly seen in the gap S between adjacent reinforcing cores 42a in the axial direction of the transport hose. In other words, the ground wire 45 does not impede the detection function. Furthermore, since the earth wire 45 is provided in the reinforcing layer 42, which is located inside the outer layer 41, it will not be exposed even if the outer layer 41 wears, and there is little risk of the earth wire breaking due to external wear, resulting in high durability overall.

[0029] The transport hose 4C in Figure 4c is the transport hose 3 in Figure 3, but with an antistatic ground wire 45 added. The ground wire 45 is spirally wound within the reinforcing layer 42 at the same pitch as the reinforcing core 42a, and is spirally wound along the reinforcing core 42a on the outside of the curved portion 42a2 extending downward from the upper apex 42a1 of the reinforcing core 42a (near the reinforcing core 42a). As with the ground wire 45 in Figure 4a, the ground wire 45 in Figure 4c is arranged so that at least a portion of its cross-sectional area (the width of the ground wire) when projected perpendicularly to the hose axis overlaps with the cross-sectional area of ​​the reinforcing core 42a when projected perpendicularly to the hose axis. Note that, as with the ground wire 45a (dotted line) in Figure 4c, the ground wire may also be arranged on the outside of the curved portion 42a4 extending upward from the lower apex 42a3 of the reinforcing core 42a. In this case, unlike the transport hose 4A in FIG. 4a and the transport hose 4B in FIG. 4b, the detection function is not impaired, and there is little risk of the earth wire breaking due to external wear, resulting in high durability overall.

[0030] The transport hose 5A of Fig. 5a is provided with a printed layer 55 bearing letters or marks on the outer side of the buffer layer 13 of the transport hose 1 of Fig. 1. Specifically, the transport hose 5A includes an outer layer 51 having a spirally irregular surface, a reinforcing layer 52 having a reinforcing core 52a, a buffer layer 53, and an inner wear-resistant layer 54. The printed layer 55 is provided on a portion of the outer surface of the buffer layer 53. The outer layer 51, reinforcing layer 52, buffer layer 53, inner wear-resistant layer 54, and reinforcing core 52a of the transport hose 5A are substantially the same as those of the transport hose 1 of Fig. 1. The printed layer 55 is made of a pigment and a translucent binder (soft synthetic resin) and is translucent as a whole. The color of the printed layer 55 is not particularly limited, as long as the letters or marks on the printed layer 55 are clearly visible from the outside when the buffer layer 53 is removed due to wear, compared to before the buffer layer 53 was worn. However, it is preferable that the color of the printed layer 55 be lower in brightness than the layers outside it (the outer layer 51 and the reinforcing layer 52) and be the same or higher in brightness as the buffer layer 53. It is particularly preferable that the color of the printed layer 55 be the same as that of the buffer layer 53. By providing the printed layer 55 in this manner, when the buffer layer 53 wears, not only does the color change, but the characters or marks on the printed layer 55 also become visible. This makes it easier to see that the inner wear-resistant layer 54 in that area has worn away. The printed layer 55 is not limited to being provided on the outer surface of the buffer layer 53, as long as it can be provided outside the buffer layer 53. For example, the transport hose 5B in FIG. 5b is printed on the outer surface of the reinforcing layer 52 of the transport hose 2 in FIG. 2. The transport hose 5C in FIG. 5c is printed on the outer surface of the reinforcing layer 52 of the transport hose 3 in FIG. 3. In either case, when the buffer layer 53 wears, not only does the color change in the worn area, but the characters or marks on the printed layer 55 also become visible.

[0031] Example 1 A transportation hose 1 having the same configuration as that shown in FIG. 1 was prepared, comprising an outer layer 11, a reinforcing layer 12 disposed on the inner side thereof, a buffer layer 13 disposed on the inner side of the reinforcing layer 12, and an inner wear-resistant layer 14 disposed on the inner side of the buffer layer 13. The outer layer 11 was made of yellow-colored soft vinyl chloride with a Shore A hardness of 61 and had a thickness of approximately 1 mm. The reinforcing core 12a of the reinforcing layer 12 was made of transparent hard vinyl chloride with a Shore D hardness of 82. The resin layer 12b of the reinforcing layer 12 was made of transparent soft vinyl chloride with a Shore A hardness of 61. The buffer layer 13 was made of blue-colored soft vinyl chloride with a Shore A hardness of 60 and had a thickness of approximately 1 mm. The inner wear-resistant layer 14 was made of transparent urethane-based resin with a Shore A hardness of 75 and had a thickness of approximately 1 mm. This is referred to as Example 1.

[0032] [Comparative Example 1] A transport hose was prepared by removing the buffer layer 13 from the transport hose 1 shown in Figure 1 and comprising an outer layer 11, a reinforcing layer 12, and an inner abrasion-resistant layer 14. Except for the outer layer 11 being transparent, the materials used were essentially the same as those of the outer layer 11, reinforcing layer 12, and inner abrasion-resistant layer 14 in Example 1. The thickness of each layer was also the same as in Example 1. This is referred to as Comparative Example 1.

[0033] [Abrasion Test] Next, the transport hoses of Example 1 and Comparative Example 1 were curved, and alumina oxide powder was sprayed toward the inner surface of the curved section for two hours. The conditions of the inner surfaces of the transport hoses after the test were compared. Fig. 6a shows the inner surface condition of the transport hose 1 of Example 1 after the test, and Fig. 6b shows cross-sectional views of the transport hose 1 of Example 1 before and after the test. Fig. 6c shows the inner surface condition of the transport hose of Comparative Example 1 after the test, and Fig. 6d shows cross-sectional views of the transport hose of Comparative Example 1 before and after the test. The amount of change in wall thickness in the areas with the most severe wear (areas indicated by arrows in Figs. 6b and 6d) was also compared. The results are shown in Table 1.

[0034]

[0035] In the transport hose of Comparative Example 1, the wear reached the reinforcing core of the reinforcing layer, whereas in Example 1, the wear did not reach the reinforcing layer 12. In addition, it was found from the amount of reduction in wall thickness that the transport hose 1 of Example 1, which is equipped with the buffer layer 13, suppressed localized uneven wear.

[0036] 1, 2, 3, 4A, 4B, 4C, 5A, 5B, 5C Transport hose 11, 21, 31, 41, 51 Outer layer 12, 22, 32, 42, 52 Reinforcing layer 12a, 32a, 42a, 52a Reinforcing core 42a1 Upper apex 42a2 Curved portion extending downward 42a3 Lower apex 42a4 Curved portion extending upward 12b, 32b, 42b Resin layer 13, 23, 33, 43, 53 Buffer layer 14, 24, 34, 44, 54 Inner wear-resistant layer 25 Reinforcing core 45 Earth wire 55 Printed layer S Gap

Claims

1. A transport hose for transporting solids or fluids, comprising a translucent outer layer, a translucent reinforcing layer provided inside the outer layer, a translucent buffer layer provided inside the reinforcing layer, and a translucent inner surface wear-resistant layer provided inside the buffer layer. A reinforcing core is spirally wound around the outside of the buffer layer. The buffer layer is colored, and the hardness of the buffer layer is lower than the hardness of the inner surface wear-resistant layer.

2. The transport hose according to claim 1, wherein the inner surface wear-resistant layer is colorless and transparent.

3. The transport hose according to claim 1, wherein the outer layer is colored in a color different from that of the buffer layer.

4. The transport hose according to any one of claims 1 to 3, wherein the reinforcing layer includes the reinforcing core.

5. The transport hose according to claim 4, having an earth wire spirally wound around the vicinity of the reinforcing core.

6. The transport hose according to claim 4, wherein spiral irregularities are formed on the outer layer.

7. The transport hose according to any one of claims 1 to 3, wherein the reinforcing core is provided outside the outer layer.

8. The transport hose according to any one of claims 1 to 3, comprising a printing layer representing characters or marks on the outside of the buffer layer.

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