Resin pipe

Abstract

To provide a resin pipe that is excellent in visibility regardless of the positional relationship between a worker and the resin pipe. [Solution] The resin pipe 1 of the present disclosure comprises a pipe body 10 and a band-shaped portion 20 extending in the pipe axis O1 direction of the pipe body 10, the band-shaped portion 20 being formed integrally with the pipe body 10, and the thickness of the band-shaped portion 20 being the same as the thickness of the pipe body 10.

Description

[Technical Field]

[0001] The present invention relates to a resin pipe. [Background technology]

[0002] Conventionally, plastic pipes such as polyethylene pipes (polyethylene plastic pipes) have been widely used for a wide variety of purposes, including water pipes and gas pipes. For this reason, plastic pipes are color-coded according to their intended use. As the number of uses for plastic pipes increases, the colors of each pipe tend to become similar even when trying to distinguish them by color tone alone. This creates a problem in that it becomes difficult to distinguish the purpose of a plastic pipe by appearance. It is particularly difficult to distinguish the purpose of a plastic pipe by color tone in dark places.

[0003] To address these problems, for example, Patent Document 1 discloses a resin pipe that is provided with one or more discrimination layers that are integrally formed on the outer surface of the body and extend in the axial direction of the body, and a method for manufacturing the same. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-218999 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the identification layer is formed only on the surface of the plastic pipe as in Patent Document 1, the visibility of the identification layer is low when the plastic pipe is viewed, for example, from the axial direction, and there is a risk that it may become difficult to identify the plastic pipes when multiple plastic pipes are stacked on top of each other.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a resin pipe that is highly visible regardless of the positional relationship between the worker and the resin pipe. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention proposes the following means. (1) A pipe body and a band-shaped portion extending in the pipe axis direction of the pipe body, the band-shaped portion being integrally formed with the pipe body, and the thickness of the band-shaped portion being the same as the thickness of the pipe body. (2) The band-shaped portion may be provided in two pieces, positioned opposite each other with the tube axis sandwiched between them, on a plane passing through the tube axis of the tube main body. (3) The band-shaped portion may form an angle of 85 degrees or more with respect to a plane perpendicular to the tube axis of the tube body. [Effects of the Invention]

[0008] According to the present invention, a resin pipe that is excellent in visibility regardless of the positional relationship between the worker and the resin pipe can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a resin pipe according to an embodiment of the present disclosure. [Figure 2] 2 is a cross-sectional view of the resin pipe shown in FIG. 1 taken along line II-II. [Figure 3] FIG. 1 is a side view of a resin pipe according to an embodiment of the present disclosure. [Figure 4] FIG. 10 is a side view showing a case where the band-shaped portion is formed in a spiral shape on the outer peripheral surface of the pipe body. [Figure 5] FIG. 1 is a diagram schematically illustrating a resin pipe manufacturing apparatus. [Figure 6] FIG. [Figure 7] FIG. 10 is a plan view showing a state in which a plurality of resin pipes are arranged in a pipe space. [Figure 8] FIG. 1 is a perspective view of a plurality of resin pipes arranged side by side. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1 and 2, a resin pipe 1 according to the present disclosure includes a pipe body 10 and a band-shaped portion 20. The resin pipe 1 may be made of, for example, polyethylene. There are no restrictions on the size of the resin pipe 1, but from the viewpoint of excellent workability when used within the pipe space PS (see Figure 7), it is preferable that the outer diameter of the resin pipe 1 be 25 mm to 120 mm, and that the thickness of the resin pipe 1 be 3 mm to 11 mm.

[0011] Hereinafter, one embodiment of a resin pipe 1 according to the present disclosure will be described with reference to FIGS. The band-shaped portion 20 extends in the direction of the pipe axis O1 of the pipe body 10. The band-shaped portion 20 extends over the entire length of the pipe body 10 in the direction of the pipe axis O1. As shown in FIG. 2, the band-shaped portion 20 is formed integrally with the pipe body 10, and the thickness d1 of the band-shaped portion 20 is the same as the thickness of the pipe body 10. In other words, the band-shaped portion 20 penetrates the pipe body 10 in the radial direction and is provided over the entire radial length of the pipe body 10. Therefore, as shown in FIG. 1, the presence or absence of the band-shaped portion 20 can be confirmed on the outer and inner peripheral surfaces of the resin pipe 1. In addition, in this embodiment, two band-shaped portions 20 are provided on a plane passing through the pipe axis O1 of the pipe body 10, so as to be opposite each other with the pipe axis O1 therebetween. The number of band-shaped portions 20 is not limited and may be one or three or more. However, from the viewpoint of recyclability, which will be described later, it is preferable to provide two band-shaped portions 20 so as to be opposite each other with the pipe axis O1 therebetween.

[0012] The length of the resin pipe 1 is determined depending on the application of the resin pipe 1, and is preferably, for example, 2 m or more and 5 m or less. Here, the length of the pipe body 10 is the distance from one open end to the other open end. The inner diameter R1 of the resin pipe 1 is determined depending on the application of the resin pipe 1, and is preferably, for example, 20 mm or more and 100 mm or less.

[0013] The color tone of the pipe body 10 is not particularly limited and is determined appropriately depending on the application and purpose.

[0014] The first resin constituting the pipe body 10 is polyethylene. The content of polyethylene in the pipe body 10 is 100 parts by mass per 100 parts by mass of the resin.

[0015] The first resin may be low-density polyethylene, medium-density polyethylene, or high-density polyethylene. Among these, high-density polyethylene is preferred as the first resin. The types of polyethylene are shown in Annex Tables 1 and 2 of JIS K 6922-1:1997. Low-density polyethylene meets the requirements of any of Class 1, Category 1 to Category 6 in Annex 2. The density of low-density polyethylene is 910 kg / m 3 More than 930kg / m 3 is less than. Medium density polyethylene meets the requirements of any of Class 2, Class 1 to Class 5 in Annex 2. The density of medium density polyethylene is 930 kg / m 3 More than 942kg / m 3 is less than. High density polyethylene meets the requirements of any of Class 3, Class 1 to Class 5 in Annex 2. The density of high density polyethylene is 942 kg / m 3 That's all. As shown in Annex Tables 1 and 2, types of polyethylene are classified by a combination of "type" and "class," such as "●type●class."

[0016] The melt flow rate (MFR) of the first resin is, for example, preferably 0.01 g / 10 min or more and 200 g / 10 min or less, more preferably 0.1 g / 10 min or more and 100 g / 10 min or less, even more preferably 0.2 g / 10 min or more and 50 g / 10 min or less, and particularly preferably 0.3 g / 10 min or more and 10 g / 10 min or less. The melt flow rate (MFR) of the first resin is a value measured in accordance with 4.1 (melt flow rate) of Appendix 1 of JIS K 6922-2:2010 at a test temperature of 190°C and a test load of 21.18N.

[0017] The tensile strength of the first resin is preferably 5.9 MPa or more, more preferably 19.6 MPa or more, and even more preferably 25 MPa or more. The upper limit of the tensile strength of the first resin is usually 100 MPa. The tensile strength of the first resin is a value measured in accordance with 4.3 (tensile test) of the appendix of JIS K 6922-2:2010.

[0018] The tensile elongation at break of the first resin is preferably 100% or more, more preferably 300% or more, and the upper limit of the tensile elongation at break of the first resin is usually 1000%. The tensile elongation at break of the first resin is a value measured in accordance with 4.3 (tensile test) of the appendix of JIS K 6922-2:2010.

[0019] The durometer hardness of the first resin is 30H D D or higher is preferable, 60H D D or higher is more preferable, 65H D The upper limit of the durometer hardness of the first resin is usually 200H D It's D. The durometer hardness of the first resin is a value measured in accordance with 4.4 (Durometer D hardness test) of Appendix 1 of JIS K 6922-2:2010.

[0020] The Vicat softening point of the first resin is preferably 65°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher. The upper limit of the Vicat softening point of the first resin is usually 150°C. The Vicat softening point of the first resin is a value measured in accordance with JIS K 6922-2:2010, Appendix 4.5 (Vicat softening point test).

[0021] The mass average molecular weight of the first resin is 0.5×10 5 Over 10.0 x 10 5 Less than 1.5 x 10 is preferable. 5 Over 3.0 x 10 5 The following is more preferable: If the mass average molecular weight is within the above range, the fluidity of the resin becomes appropriate, and productivity can be increased. The mass average molecular weight of the first resin is measured in accordance with JIS K 7252-1:2008.

[0022] The number average molecular weight of the first resin is 0.1×10 4 Over 2.0 x 10 4 Less than 0.5 x 10 is preferable. 4 Over 1.0 x 10 4 The following is more preferable: If the number average molecular weight is within the above range, the fluidity of the resin becomes appropriate, and productivity can be increased. The number average molecular weight of the first resin is measured in accordance with JIS K 7252-1:2008.

[0023] The glass transition point of the first resin is preferably −140° C. or higher and −90° C. or lower, and more preferably −120° C. or higher and −100° C. If the glass transition point is within the above range, the resin has appropriate fluidity, which increases productivity. The glass transition point of the first resin is a value measured by a differential scanning calorimeter (DSC).

[0024] The melting point of the first resin is preferably 110° C. or higher and 130° C. or lower, and more preferably 120° C. or higher and 125° C. or lower. If the melting point is within the above range, the resin has appropriate fluidity, which increases productivity. The melting point of the first resin is a value measured by a differential scanning calorimeter (DSC).

[0025] The crystallinity of the first resin is preferably 60% to 80%, more preferably 65% ​​to 70%. If the crystallinity is within the above range, the resin has appropriate fluidity, which increases productivity. The crystallinity of the first resin is a value measured by DSC.

[0026] The pencil hardness of the first resin is preferably HB or more and 7B or less, and more preferably HB or more and 6B or less. If the pencil hardness is within the above range, the resin is less susceptible to scratches and the appearance can be further improved. The pencil hardness of the first resin is a value measured in accordance with JIS K 5600-5-4:1999.

[0027] The content of the first resin is preferably 90% by mass or more and 99.99999% by mass or less with respect to the total mass of the pipe body 10.

[0028] The tube body 10 may contain additives such as colorants, antioxidants, ultraviolet absorbers (UVA), and hindered amine light stabilizers (HALS). The content of the additive in the pipe body 10 is determined taking into consideration the type of additive. The content of the additive per 100 parts by mass of the first resin is 1.0 × 10 -5 Parts by mass or more and 10 parts by mass or less are preferred, and 1.0 × 10 -3 Parts by mass or more and 1.0 parts by mass or less are more preferable.

[0029] In this embodiment, the length of the band-shaped portion 20 is the same as the length of the pipe body 10. The length of the band-shaped portion 20 may be the same as or different from the length of the pipe body 10. It is preferable that the length of the band-shaped portion 20 is the same as the length of the pipe body 10.

[0030] The width w2 of the band-shaped portion 20 (i.e., the length in the circumferential direction of the resin pipe 1) is determined appropriately depending on the purpose of the band-shaped portion 20. The ratio of the width w2 to the outer circumference (circumferential length around the pipe axis O1) of the resin pipe 1 (w2 ratio) is preferably 1 to 50%. From the viewpoint of facilitating separation of the pipe body 10 and the band-shaped portion 20 when recycling the resin pipe 1 and improving recyclability, the ratio of the width w2 to the outer circumference (circumferential length around the pipe axis O1) of the resin pipe 1 (w2 ratio) is more preferably less than 5%. The w2 ratio is calculated by [width w2 of the band-shaped portion 20]÷[perimeter of the resin pipe 1]×100. The width of the belt-shaped portion 20 is not limited to a specific value, but may be, for example, 1 mm or more and 20 mm or less. From the viewpoint of ensuring visibility, the width of the belt-shaped portion 20 is preferably 2 mm or more. From the viewpoint of improving recyclability, the width of the belt-shaped portion 20 is more preferably 10 mm or less, and even more preferably 4 mm or less.

[0031] When multiple band portions 20 are provided in the circumferential direction as in this embodiment, from the viewpoint of improving recyclability, the total width of the band portions 20 relative to the outer periphery of the pipe body 10 is preferably less than 30%. The total width of the band portions 20 relative to the outer periphery of the pipe body 10 is more preferably less than 20%, and even more preferably less than 15%.

[0032] The inclination of the band-shaped portion 20 with respect to the tube axis O1 of the tube main body 10 will be described with reference to FIGS. FIG. 3 shows a case where the band-shaped portion 20 is parallel to the tube axis O1 of the pipe body 10. On the other hand, as shown in FIG. 4, if the band-shaped portion 20 is not parallel to the tube axis O1 of the pipe body 10 (is twisted), grinding the band-shaped portion to align with the tube axis O1 of the pipe body or cutting the resin pipe 1 along a plane passing through the tube axis O1 to separate the pipe body 10 and the band-shaped portion 20 takes time, reducing recyclability. Therefore, the angle θ of the band-shaped portion 20 with respect to a plane perpendicular to the tube axis O1 of the pipe body 10 (twist angle) is preferably 85 degrees or more and preferably 90 degrees or less. Note that when the band-shaped portion 20 is arranged along the tube axis O1 of the pipe body 10, the angle θ is approximately 90 degrees.

[0033] The color tone of the band-shaped portion 20 is not particularly limited, but it is preferable that it be different from the color tone of the pipe body 10 . The color tone of the band-like portion 20 is different from the color tone of the pipe body 10, thereby creating a striped pattern on the outer periphery of the resin pipe 1. By combining the colors of the band-like portion 20 and the pipe body 10, the color variations of the resin pipe 1 are increased.

[0034] The second resin constituting the strip portion 20 is polyethylene containing low-density polyethylene, medium-density polyethylene, or a mixture thereof. The content of the second resin in the strip portion 20 is 100 parts by mass per 100 parts by mass of the resin.

[0035] The total content of the low-density polyethylene and the medium-density polyethylene per 100 parts by mass of the second resin is preferably 50 parts by mass or more, more preferably 80 parts by mass or more, and even more preferably 100 parts by mass. When the content is equal to or more than the above lower limit, the fluidity of the second resin is easily increased.

[0036] The second resin species and the first resin species may be the same or different. When the type of the second resin is different from the type of the first resin, it is preferable that the density of the second resin is smaller than the density of the first resin. If the density of the second resin is smaller than the density of the first resin, the fluidity of the second resin in the extruder is increased, and an increase in the back pressure of the extruder can be further suppressed. This further reduces the load on the extruder.

[0037] When the type of the second resin is the same as the type of the first resin, it is preferable that the second resin have a larger polyethylene "class" number in Appendix Table 2 of JIS K 6922-1:1997. That is, if the first resin is Class 2, Class 1, it is preferable that the second resin be Class 2, Class 2 to Class 5. By increasing the class number, the fluidity of the second resin in the extruder is improved, and an increase in the back pressure of the extruder can be further suppressed. This further reduces the load on the extruder.

[0038] Preferred examples of the combination of the first resin and the second resin are shown in (a), (b) and (c). (a) The first resin is high density polyethylene and the second resin is medium density polyethylene. (b) The first resin is high density polyethylene and the second resin is low density polyethylene. (c) The first resin is high density polyethylene and the second resin is a blend of low density polyethylene and medium density polyethylene.

[0039] The MFR of the second resin is preferably 0.1 g / 10 min or more and 200 g / 10 min or less, and more preferably 0.4 g / 10 min or more and 100 g / 10 min or less. The MFR of the second resin is preferably greater than the MFR of the first resin. The difference between the MFR of the second resin and the MFR of the first resin is preferably 0.3 g / 10 min or more, more preferably 1.0 g / 10 min or more. If the difference in MFR between the first resin and the second resin is within the above range, the appearance of the band-shaped portion 20 can be further improved and the load on the extruder can be further reduced. The upper limit of the difference between the MFR of the second resin and the MFR of the first resin is, for example, 20 g / 10 min.

[0040] The tensile strength of the second resin is preferably 5.9 MPa or more, more preferably 9.8 MPa or more, and the upper limit of the tensile strength of the second resin is usually 100 MPa. The difference between the tensile strength of the second resin and the tensile strength of the first resin is preferably 5.0 MPa or more, and more preferably 10.0 MPa or more. If the difference in tensile strength between the first resin and the second resin is within the above range, the appearance of the strip portion 20 can be further improved and the load on the extruder can be further reduced. The upper limit of the difference between the tensile strength of the second resin and the tensile strength of the first resin is, for example, 20 MPa.

[0041] The tensile elongation at break of the second resin is preferably 100% or more, more preferably 300% or more, and the upper limit of the tensile elongation at break of the second resin is usually 1000%. The difference between the tensile elongation at break of the second resin and the tensile elongation at break of the first resin is preferably 50% or more, and more preferably 100% or more. If the difference in tensile elongation at break between the first resin and the second resin is within the above range, the appearance of the band-shaped portion 20 can be improved and the load on the extruder can be further reduced. The upper limit of the difference between the tensile elongation at break of the second resin and the tensile elongation at break of the first resin is, for example, 200%.

[0042] The durometer hardness of the second resin is 30H D D or higher is preferred, 45H D The upper limit of the durometer hardness of the second resin is usually 100H D It's D. The difference in durometer hardness between the second resin and the first resin is 15H D D or higher is preferred, 30H D D or higher is more preferable. If the difference in durometer hardness between the first resin and the second resin is within the above range, the appearance of the band-shaped portion 20 can be improved and the load on the extruder can be further reduced. The upper limit of the difference between the durometer hardness of the second resin and the durometer hardness of the first resin is, for example, 50H. D It's D.

[0043] The Vicat softening point of the second resin is preferably 65°C or higher, and more preferably 80°C or higher. The upper limit of the Vicat softening point of the second resin is usually 130°C. The difference between the Vicat softening point of the second resin and the Vicat softening point of the first resin is preferably 5°C or more, more preferably 10°C or more. If the difference in Vicat softening point between the first resin and the second resin is within the above range, the appearance of the belt-like portion 20 can be improved and the load on the extruder can be further reduced. The upper limit of the difference between the Vicat softening point of the second resin and the Vicat softening point of the first resin is, for example, 30°C.

[0044] The mass average molecular weight of the second resin is 1.0×10 2 Over 2.0 x 10 5 Less than 1.5 x 10 is preferable. 3 Over 1.5 x 10 5 The following is more preferred: The difference between the mass average molecular weight of the second resin and the mass average molecular weight of the first resin is 1.5 × 10 5 More than 3.0 × 10 is preferable. 5 The above is more preferable. If the difference in mass average molecular weight between the first resin and the second resin is within the above range, the appearance of the strip portion 20 can be improved and the load on the extruder can be further reduced. The upper limit of the difference between the mass average molecular weight of the second resin and the mass average molecular weight of the first resin is, for example, 3.0 × 10 5 is.

[0045] The number average molecular weight of the second resin is 1.0×10 3 Over 10.0 x 10 3 Less than 1.5 x 10 is preferable. 3 Over 5.0 x 10 3 The following is more preferred:

[0046] The glass transition point of the second resin is preferably -135°C or higher and -95°C or lower, and more preferably -125°C or higher and -105°C or lower. The difference between the glass transition point of the second resin and the glass transition point of the first resin is preferably 0°C or more and 10°C or less, more preferably 0°C or more and 5°C or less. If the difference in glass transition point between the first resin and the second resin is within the above range, the appearance of the strip portion 20 can be improved and the load on the extruder can be further reduced.

[0047] The melting point of the second resin is preferably 100°C or higher and 120°C or lower, and more preferably 115°C or higher and 120°C or lower. The difference between the melting point of the second resin and the melting point of the first resin is preferably 0°C or higher and 10°C or lower, more preferably 0°C or higher and 5°C or lower. If the difference in melting point between the first resin and the second resin is within the above range, the appearance of the band-shaped portion 20 can be made better.

[0048] The crystallinity of the second resin is preferably 30% or more and 60% or less, and more preferably 40% or more and 60% or less. The difference between the crystallinity of the second resin and the crystallinity of the first resin is preferably 5% or more, and more preferably 10% or more. If the difference in crystallinity between the first resin and the second resin is within the above range, the appearance of the strip portion 20 can be improved and the load on the extruder can be further reduced. The upper limit of the difference between the crystallinity of the second resin and the crystallinity of the first resin is, for example, 50%.

[0049] The pencil hardness of the second resin is preferably HB or more and 7B or less, and more preferably HB or more and 6B or less. The difference between the pencil hardness of the second resin and the pencil hardness of the first resin is preferably 2B or less, more preferably 1B or less. If the difference in hardness between the first resin and the second resin is within the above range, the appearance of the band-shaped portion 20 can be improved and the load on the extruder can be further reduced.

[0050] The content of the second resin is preferably 90% by mass or more and 99.99999% by mass or less with respect to the total mass of the strip portion 20.

[0051] The band-shaped portion 20 may contain an additive. The additive contained in the band-shaped portion 20 is the same as the additive contained in the pipe body 10. The additive in the pipe body 10 and the additive in the band-shaped portion 20 may be the same or different. The content of the additive in the strip portion 20 is determined taking into consideration the type of additive. The content of the additive per 100 parts by mass of the second resin is 1.0×10 -5 Parts by mass or more and 10 parts by mass or less are preferred, and 1.0 × 10 -3 Parts by mass or more and 1.0 parts by mass or less are more preferable.

[0052] A manufacturing apparatus for manufacturing the resin pipe 1 configured as above will be described. As shown in Fig. 5, the manufacturing apparatus 51 includes a co-extrusion molding machine 52, a cooling section 53, a printing machine 55, a take-up machine 54, and a cutting machine 56. In Fig. 4, a portion of a molding die 52a (described later) that forms a second flow path 52c is indicated by a two-dot chain line so that the inside can be easily seen. The co-extrusion molding machine 52, cooling section 53, printing machine 55, take-up machine 54, and cutting machine 56 are arranged in this order from the upstream side to the downstream side along which the resin pipe 1 (continuous resin pipe 1A described later) is transported.

[0053] A first flow path 52b and a second flow path 52c are formed in a molding die 52a of the co-extrusion molding machine 52. In this embodiment, four second flow paths 52c are formed in the molding die 52a. The four second flow paths 52c merge with the first flow path 52b from the side of the first flow path 52b. A resin material (first resin) for forming the pipe body 10 is supplied in a molten state to the first flow path 52b. A resin material (second resin) for forming the band-shaped portion 20 is supplied in a molten state to the second flow path 52c. A continuous resin pipe 1A is extruded downstream from the molding die 52a. The continuous resin pipe 1A is formed by continuously connecting resin pipes 1 in the direction of the axis C. 5 shows the central axis C1 of the molding die 52a of the co-extrusion molding machine 52 as viewed from the downstream side toward the upstream side. In order to focus on the position of the central axis C1, the molding die 52a is indicated by a two-dot chain line.

[0054] The cooling section 53 is composed of a water tank, etc. The cooling section 53 cools the continuous resin pipe 1A molded by the co-extrusion molding machine 52 using water, etc.

[0055] 6, the haul-off machine 54 has a plurality of endless tracks 58. The plurality of endless tracks 58 are arranged around a predetermined central axis C2 at intervals. In this example, the haul-off machine 54 has four endless tracks 58. Each endless track 58 has a plurality of holding members 59. A recess 59a is formed in the center of the width direction (circumferential direction) of each holding member 59. When a drive motor (not shown) is rotated, the portion of the endless track 58 facing the central axis C2 moves downstream or upstream.

[0056] The endless track 58 is supported by support members 61 and the like via a known distance adjustment mechanism 60. Each support member 61 is fixed to a frame or the like (not shown). For example, the distance adjustment mechanism 60 is provided with a lever (not shown). Rotating the lever moves the endless track 58 toward or away from the support members 61, adjusting the distance between the endless track 58 and the central axis C2. The distance adjustment mechanism 60 adjusts the position of the endless track 58 in a first direction D1 toward and away from the central axis C2.

[0057] The multiple endless tracks 58 hold the continuous resin pipe 1A on the central axis C2. At this time, a portion of the outer circumferential surface of the continuous resin pipe 1A fits into the recess 59a of each holding member 59 of the endless tracks 58. This allows the multiple endless tracks 58 to securely hold the continuous resin pipe 1A. The axis C of the continuous resin pipe 1A held by the multiple endless tracks 58 is aligned with the central axis C2. When each of the endless tracks 58 rotates in a predetermined direction, the continuous resin pipe 1A is drawn downstream.

[0058] The haul-off machine 54 may also be provided with a position adjustment mechanism that adjusts the position of the endless tracks 58 in the second direction D2, which is the tangent direction of a circle centered on the central axis C2. With this configuration, if the centers of the multiple endless tracks 58 deviate from the central axis C2, the position adjustment mechanism and the distance adjustment mechanism 60 can be used to adjust the centers of the multiple endless tracks 58 so that they coincide with the central axis C2.

[0059] As described above, the resin pipe 1 of the present disclosure comprises a pipe main body 10 and a band-shaped portion 20 extending in the pipe axis O1 direction of the pipe main body 10, the band-shaped portion 20 being formed integrally with the pipe main body 10, and the thickness of the band-shaped portion 20 being the same as the thickness of the pipe main body 10. If the band-like portion 20 is formed only on the surface of the plastic pipe 1, for example, when the plastic pipe 1 is viewed from the direction of the axis O1, the visibility of the band-like portion 20 may not be ensured. In particular, when multiple plastic pipes 1 are gathered in a narrow and dark pipe space PS, it may not be easy to confirm whether or not the band-like portion 20 is present on the surface of the plastic pipe 1. With the above configuration, the thickness of the band-shaped portion 20 is the same as the thickness of the pipe body 10. Therefore, as shown in FIG. 7, the presence or absence of the band-shaped portion 20 can be easily confirmed, for example, when viewing the plastic pipe 1 from the direction of the axis O1. Furthermore, because the thickness of the band-shaped portion 20 is the same as the thickness of the pipe body 10, the band-shaped portion 20 can also be confirmed from the inner peripheral surface of the plastic pipe 1. Because the band-shaped portion 20 can also be confirmed from the inner peripheral surface of the plastic pipe 1, for example, when viewing multiple plastic pipes 1 lined up in the pipe space PS from diagonally above, as shown in FIG. 8, the presence or absence of the band-shaped portion 20 of the plastic pipe 1 can be confirmed by checking the inner peripheral surface of the plastic pipe 1. Therefore, the plastic pipe 1 can be made to have excellent visibility regardless of the positional relationship between the worker and the plastic pipe 1.

[0060] Furthermore, two strip-shaped portions 20 may be provided on a plane passing through the tube axis O1 of the tube main body 10, so as to be positioned opposite each other with the tube axis O1 sandwiched therebetween. Since the pipe body 10 and the band-like portion 20 are different colors, when recycling the resin pipe 1, it is necessary to separate the pipe body 10 and the band-like portion 20 from the viewpoint of preventing the recycled pipe from having poor color. When the thickness of the band-like portion 20 is the same as that of the pipe body 10, if two band-like portions 20 are provided so as to be positioned on a plane passing through the pipe axis O1 of the pipe body 10, the pipe body 10 and the band-like portion 20 can be separated by cutting the resin pipe 1 on the plane passing through the pipe axis O1, thereby reducing the time required to separate the pipe body 10 and the band-like portion 20. This makes it possible to produce a resin pipe 1 that is highly visible and can be easily recycled.

[0061] The band-shaped portion 20 may form an angle of 85 degrees or more with respect to a plane perpendicular to the tube axis O1 of the tube main body . If the band-like portion 20 is formed in a spiral shape on the outer peripheral surface of the pipe body 10, it takes time to grind or cut the band-like portion 20 when recycling the resin pipe 1. As described above, if the angle that the band-like portion 20 forms with respect to a plane perpendicular to the tube axis O1 of the tube main body 10 is 85 degrees or more, the tube main body 10 and the band-like portion 20 can be separated by grinding the band-like portion 20 along the tube axis O1 of the tube main body 10 or by cutting the band-like portion 20 along a plane passing through the tube axis O1 of the resin pipe 1. This reduces the time required to separate the discrimination layer from the tube main body 10. This makes it possible to produce a resin pipe 1 that is easily recyclable.

[0062] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and configuration changes, combinations, deletions, etc. are also included within the scope that does not deviate from the gist of the present invention.

[0063] For example, in the manufacturing apparatus 51, the printing machine 55 may be disposed between the take-up machine 54 and the cutting machine 56. Configuring the manufacturing apparatus 51 in this manner makes it possible to prevent the band-shaped portion 20 from twisting relative to the axis C of the pipe body 10. Furthermore, the take-up machine 54 has four endless tracks 58, but when two band-shaped portions 20 are provided as in this embodiment, two endless tracks 58 may be provided. For example, a stencil may be provided on the outer surface of the resin pipe 1. In the above embodiment, the band-shaped portion 20 is integrally formed with the pipe body 10 by co-extrusion molding, but the method for forming the band-shaped portion 20 is not limited to this. [Explanation of symbols]

[0064] 1. Resin pipe 10 tube body 20 fascia

Claims

1. A tube body; a band-shaped portion extending in the axial direction of the pipe body; Equipped with The band-shaped portion is integrally formed with the pipe body, The thickness of the band portion is the same as the thickness of the pipe body. Resin pipe.

2. The two band-shaped portions are provided on a plane passing through the tube axis of the tube main body so as to be positioned opposite each other with the tube axis therebetween. The resin pipe according to claim 1.

3. The band-shaped portion forms an angle of 85 degrees or more with respect to a plane perpendicular to the tube axis of the tube body. The resin pipe according to claim 1 or 2.

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