Pipe pillow

Abstract

To provide a pipe pillow made of a resin composition including various components such as a recycled container wrapping material.SOLUTION: A pipe pillow 1 is made of a resin composition including polypropylene and polyethylene, where the resin composition includes 70 mass% or more of polypropylene and 30 mass% or less of polyethylene.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pipe support for pipes.

Background Art

[0002] Conventionally, it has been considered to manufacture a pipe support for pipes from a resin obtained by recovering a thermoplastic resin having a formed history.

[0003] For example, Japanese Patent Application Laid-Open No. 2001-280545 (Patent Document 1) discloses recovering a polypropylene packaging bundling band and manufacturing a pipe support for pipes.

[0004] On the other hand, in order to reduce the amount of plastic container packaging waste, which accounts for about 20-30% by weight and about 60% by volume of the waste discharged from households, and to effectively utilize resources, the Container Packaging Recycling Law has been implemented. Such plastic container packaging waste is separately collected by municipalities, and polypropylene and polyethylene, which are recyclable plastics, are selected, and processed such as crushing and washing. What is obtained by selecting polypropylene and polyethylene in this way is also called a "container packaging recycled material", and attempts have been made to mold alternative products of plastic products from pellets manufactured from this container packaging recycled material (for example, Patent Document 2).

[0005] However, most of the polyolefin-based resins that are the main components of the container packaging recycled material are derived from various products such as packaging films, disposable containers, and shopping bags, and contain various types of polyolefin-based resins. In addition, it is difficult to completely remove impurities in the separation process and the separation step, and usually, the container packaging recycled material contains impurities such as other resins and inorganic substances other than the polyolefin-based resin. Since the quality of the container packaging recycled material is not stable in this way, resin molded products using the container packaging recycled material may have insufficient physical properties such as mechanical strength depending on the application.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The pipe pillow of Patent Document 1 is formed using a binding band for packing waste products as a raw material. However, its raw material is manufactured by collecting specific resin products and has relatively stable quality. However, the use of waste plastics containing various components such as container packaging recyclable materials as a raw material for forming pipe pillows has not been sufficiently studied.

[0008] Therefore, there is a demand for providing a pipe pillow made of a resin composition containing various components such as container packaging recyclable materials.

Means for Solving the Problems

[0009] The pipe pillow of the present invention is a pipe pillow made of a resin composition containing polypropylene and polyethylene, wherein the proportion of the polypropylene in the resin composition is 70% by mass or more, and the proportion of the polyethylene in the resin composition is 30% by mass or less.

[0010] According to this configuration, a pipe pillow made of a resin composition containing various components such as container packaging recyclable materials as a raw material can be realized.

[0011] Hereinafter, preferred embodiments of the present invention will be described. However, the scope of the present invention is not limited by the preferred embodiment examples described below.

[0012] In one aspect, the pipe cushion of the present invention preferably contains a chlorine-based resin in the resin composition, and the proportion of the chlorine-based resin in the resin composition is 3% by mass or less.

[0013] According to this configuration, since the proportion of the chlorine-based resin in the resin composition is at a certain proportion or less, it is easy to manufacture a pipe cushion that achieves both moldability and strength.

[0014] In one aspect, the pipe cushion of the present invention preferably contains polystyrene in the resin composition, and the proportion of the polystyrene in the resin composition is 5% by mass or less.

[0015] According to this configuration, since the proportion of polystyrene in the resin composition is at a certain proportion or less, it is easy to manufacture a pipe cushion that achieves both moldability and strength.

[0016] In one aspect, the pipe cushion of the present invention preferably contains titanium oxide in the resin composition, and the proportion of the titanium oxide in the resin composition is 5% by mass or less.

[0017] According to this configuration, since the proportion of titanium oxide in the resin composition is at a certain proportion or less, it is easy to manufacture a pipe cushion that achieves both moldability and strength.

[0018] In one aspect, the pipe cushion of the present invention is preferably made of a container packaging recyclable material.

[0019] According to this configuration, since a container packaging recyclable material can be used as a raw material for the resin composition for forming the pipe cushion, resources can be effectively utilized.

[0020] Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments described with reference to the drawings.

Brief Description of the Drawings

[0021]

Figure 1

Mode for Carrying Out the Invention

[0022] An embodiment of the pipe pillow according to the present invention will be described with reference to FIG. 1. Hereinafter, an example in which the pipe pillow 1 for piping of the present embodiment is applied to a pipe pillow that supports piping such as a protective pipe for various cables will be described. The rear view is omitted because it is symmetric with the front view about the left and right.

[0023] In addition, when using terms representing directions in the following description, unless otherwise specified, each term is used based on the posture when the pipe pillow 1 is installed with the bottom surface portion 16 as the grounding portion (that is, the posture shown in FIG. 1(a)). For example, the vertical direction and the up-down direction are the up-down directions of the paper surface of FIG. 1(a), the depth direction is the direction orthogonal to the paper surface of FIG. 1(a), and the left-right direction and the width direction are the left-right directions of the paper surface of FIG. 1(a).

[0024] ≪Shape of Pipe Pillow≫ In the present embodiment, the pipe pillow 1 is a resin molded product having a thin-walled contour with a thickness of about 2.5 mm and having a cavity inside. On the upper surface, there are provided a semi-circular arc-shaped portion 11 on which a cylindrical pipe is placed, and a right upper surface portion 12 and a left upper surface portion 13 located on both the left and right sides adjacent to the arc-shaped portion 11. Further, there are provided a right side wall portion 14 and a left side wall portion 15 extending vertically from the outer edges of the right upper surface portion 12 and the left upper surface portion 13. The right side wall portion 14 and the left side wall portion 15 are continuously provided to the bottom surface portion 16. In FIG. 1(a), the pipe pillow 1 has a dimension in the width direction (the shortest distance from the right side wall portion 14 to the left side wall portion 15) of about 200 mm, a dimension in the up-down direction (the shortest distance from the right upper surface portion 12 to the bottom surface portion 16) of about 100 mm, and a depth dimension (the left-right dimension in the paper surface of FIGS. 1(b)(c), the up-down dimension in the paper surface of FIGS. 1(d)(e)) of about 100 mm.

[0025] The pipe pillow 1 is configured to be joinable in a free combination with other pipe pillows arranged adjacent to each other horizontally and vertically by fitting the concave and convex portions provided in each part. Specifically, on the upper and lower surfaces, the second and third pipe pillows (not shown) with the up-down and left-right reversed are respectively joinable, and on the left and right, the fourth and fifth pipe pillows (not shown) arranged adjacent to each other in parallel are joinable.

[0026] The upper right surface portion 12 has a protrusion 22 that fits into the recess 23 of the upper left surface portion 13 of the second pipe pillow, and the upper left surface portion 13 has a recess 23 that fits into the protrusion 22 of the second pipe pillow. The protrusion 22 is composed of two elastic pieces having stepped portions, which are divided by a slit 22a, and these two elastic pieces are locked by being elastically held in the recess 23. Also, the bottom surface portion 16 has a pair of concave grooves 26 and a pair of ridges 27 that are joined to a pair of ridges 27 and concave grooves 26 of the third pipe pillow arranged below it. The right side wall portion 14 has a concave groove 24 that is joined to the ridge 25 of the fifth pipe pillow arranged adjacent to its right side, and the left side wall portion 15 has a ridge 25 that is joined to the concave groove 24 of the fourth pipe pillow arranged adjacent to its left side.

[0027] The concave groove 24 has a pair of protruding pieces 24a and 24b that protrude inward from each other at the central portion in its longitudinal direction. Also, the ridge 25 has a pair of protruding pieces 25a and 25b that protrude outward from each other at the central portion in its longitudinal direction. The pipe pillow 1 can slide the ridge 25 of the second pipe pillow adjacent to the concave groove 24 in the depth direction and fit them together. At this time, the protruding piece 24a and the protruding piece 25a, and the protruding piece 24b and the protruding piece 25b overlap each other and are locked to each other. In this way, a plurality of pipe pillows 1 can be joined and used in the left-right direction. Similarly, in the downward direction, the concave groove 26 and the ridge 27 of the pipe pillow 1 are respectively locked to and joined with the ridge 27 and the concave groove 26 of the pipe pillow adjacent to the lower side.

[0028] Inside the pipe support 1, as shown in Fig. 1(d), there is a thin-walled partition portion 19 (19a to 19f) at a position crossing the centers of the upper right surface portion 12, the arcuate portion 11, and the upper left surface portion 13. On both sides of the partition portion 19, thin-walled reinforcing ribs are provided so as to connect the right corner portion 17 defined by the right side wall portion 14 and the bottom surface portion 16 and the arcuate portion 11, and thin-walled reinforcing ribs are provided so as to connect the left corner portion 18 defined by the left side wall portion 15 and the bottom surface portion 16 and the arcuate portion 11. Further, on both sides of the partition portion 19, three thin-walled reinforcing ribs are provided in parallel so as to connect the bottom of the arcuate portion 11 and the bottom surface portion 16. Each corner portion has a rounded shape.

[0029] ≪Resin composition≫ The pipe support 1 of the present embodiment is formed from a resin composition containing polypropylene and polyethylene, the proportion of polypropylene in the resin composition is 70% by mass or more, and the proportion of polyethylene in the resin composition is 30% by mass or less.

[0030] The resin composition used for molding the pipe support of the present embodiment is, for example, made of a container packaging recyclable material. The container packaging recyclable material is obtained by separating and sorting plastic container packaging waste discharged from households for reuse and making it available as a raw material for recycled molded articles. Specifically, in the sorting process, after crushing the plastic container packaging waste, multi-sorters or manual separation is performed, and it is roughly sorted into various categories such as polyethylene, polypropylene, and polystyrene. The order of sorting by a multi-sorter or the like is not limited, but for example, the following examples can be cited. (1) First, select the material mainly composed of polypropylene, then select the material mainly composed of polyethylene, and then select the material mainly composed of polystyrene, etc. (2) First, select the material mainly composed of polyethylene, then select the material mainly composed of polypropylene, and then select the material mainly composed of polystyrene, etc. In this way, the materials mainly composed of polyethylene, the materials mainly composed of polypropylene, etc., which are selected at each stage, each pass through an intermediate process and are finally formed into pellets by a granulator, and are used as container packaging recycling materials respectively. However, for the materials mainly composed of polyethylene and the materials mainly composed of polypropylene, it is difficult to accurately select each of them at once from a mixture of polyethylene and polypropylene. Therefore, before forming into pellets or the like, the once-selected materials may be further selected by the same method or other methods. Examples of the method for selecting each from a mixture of polyethylene and polypropylene include methods such as separation by infrared light and separation by floating and using specific gravity. Further, each method may be repeatedly carried out a plurality of times to increase the content ratio of the target component.

[0031] The resin composition according to the present embodiment is preferably obtained by granulating the container packaging recycling material obtained as the material mainly composed of polypropylene by the above-described selection to form pellets. Therefore, the container packaging recycling material according to the present embodiment contains polypropylene as a main component and may contain polyethylene as a sub-component. The sub-component is a component that is difficult to completely remove even when a plurality of selection methods and a plurality of selections as described above are carried out. Note that the state of the resin composition used for forming the pipe pillow according to the present embodiment is not limited, and it may be a state in which a recycling material such as a container packaging recycling material is crushed and then compressed and solidified, a state in which this is melted to form a homogeneous resin composition, or a mixture of a plurality of states. It is preferable that a rough selection as described above has been carried out at least once for the recycling material such as the container packaging recycling material, but the presence or absence of the selection is not limited as long as the characteristics of the pipe pillow of the present invention are not impaired.

[0032] Note that the above-described intermediate process is a process for further removing impurities and includes sorting, washing, pulverizing, and separation by specific gravity. It is preferable that the container packaging recycling material mainly composed of polypropylene selected in the second selection process also has other resins, inorganic substances, etc. removed to some extent through the intermediate process before being formed into pellets.

[0033] The polypropylene contained in the resin composition of the present embodiment is derived from, for example, waste such as packaging films and disposable food containers (including main bodies and lids), and is a propylene homopolymer, a block, random, or graft copolymer of propylene and other olefins, or a mixture thereof. Examples of other olefins include ethylene, butene, pentene, hexene, heptene, 4-methylpentene, etc., which are α-olefins.

[0034] The proportion of polypropylene in the resin composition of the present embodiment may be 70% by mass or more, preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. If the proportion of polypropylene in the resin composition is 70% by mass or more, it is easy to obtain mechanical strength and the like comparable to the required performance of conventional pipe pillows made of virgin raw materials. The upper limit of the proportion of polypropylene in the resin composition is not limited, but may be, for example, 95% by mass or less. The balance may be other components such as polyethylene.

[0035] The polyethylene contained in the resin composition is derived from, for example, waste such as packaging films and plastic shopping bags, and includes low-density polyethylene-based resins, medium-density polyethylene-based resins, high-density polyethylene-based resins, linear low-density polyethylene-based resins, linear medium-density polyethylene-based resins, linear high-density polyethylene-based resins, copolymers of ethylene and α-olefins, etc. Usually, a plurality of types of polyethylene can be mixed.

[0036] The proportion of polyethylene in the resin composition of the present embodiment may be 30% by mass or less, preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less. If the proportion of polyethylene in the resin composition is 30% by mass or less, good moldability is easily obtained. The lower limit of the proportion of polyethylene in the resin composition is not limited, but may be 1% by mass or more.

[0037] The resin composition of this embodiment is made of a container packaging recyclable material, and in addition to polypropylene and polyethylene, it may contain a chlorine-based resin, polystyrene, and titanium oxide.

[0038] The proportion of the chlorine-based resin in the resin composition of this embodiment is preferably 3% by mass or less. The proportion of the chlorine-based resin in the resin composition is more preferably 2% by mass or less, and even more preferably 1% by mass or less. If the proportion of the chlorine-based resin in the resin composition is 3% by mass or less, it is easy to obtain mechanical strength comparable to that of conventional pipe pillows.

[0039] Examples of the chlorine-based resin include chlorine-containing resins such as polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC). These may be derived from wastes such as trays, containers, and wrap films.

[0040] The proportion of polystyrene in the resin composition of this embodiment is preferably 5% by mass or less. The proportion of polystyrene in the resin composition is more preferably 3% by mass or less, even more preferably 2% by mass or less, and particularly preferably 1% by mass or less. If the proportion of polystyrene in the resin composition is 5% by mass or less, it is easy to obtain mechanical strength comparable to that of conventional pipe pillows. Polystyrene may be mainly derived from wastes such as foamed polystyrene containers, trays, and styrene containers.

[0041] The proportion of titanium oxide in the resin composition of this embodiment is preferably 5% by mass or less. The proportion of titanium oxide in the resin composition is more preferably 3% by mass or less, even more preferably 2% by mass or less, and particularly preferably 1% by mass or less. If the proportion of titanium oxide in the resin composition is 5% by mass or less, it is easy to obtain mechanical strength comparable to that of conventional pipe pillows. Titanium oxide may be derived from, for example, white pigments contained in containers, films, trays, etc.

[0042] The resin composition according to this embodiment may contain impurities that are difficult to completely remove in addition to the components described above. Examples of such impurities include resins such as polyester resins like polyethylene terephthalate and polyamide resins like nylon, and inorganic substances such as talc and metals (aluminum, iron, etc.). These impurities can usually be contained in the resin composition at a ratio of about 0.1 to 5% by mass.

[0043] In this embodiment, the pipe pillow 1 is molded using a resin composition containing polypropylene, polyethylene, chlorine-based resin, polystyrene, and titanium oxide in the above-described ratios. These blending ratios are not limited as long as they are within the above-described range, and for example, they can be blending ratios such as the following (A) to (C). (A) 70 to 95% by mass of polypropylene, 0.5 to 10% by mass of polyethylene, 0.5 to 3% by mass of chlorine-based resin, 0.5 to 5% by mass of polystyrene, 0.5 to 5% by mass of titanium oxide, and 1 to 7% by mass of others (B) 85 to 95% by mass of polypropylene, 0.5 to 5% by mass of polyethylene, 0.5 to 2% by mass of chlorine-based resin, 0.5 to 2% by mass of polystyrene, 0.5 to 2% by mass of titanium oxide, and 1 to 4% by mass of others (C) 89 to 99% by mass of polypropylene, 0.1 to 5% by mass of polyethylene, 0.1 to 2% by mass of chlorine-based resin, 0.1 to 2% by mass of polystyrene, 0.1 to 2% by mass of titanium oxide, and 0.1 to 4% by mass of others

[0044] In the resin composition according to this embodiment, colorants such as black pigments, antioxidants, antistatic agents, and other components may be blended within a range that does not impair the characteristics of the pipe pillow of the present invention.

[0045] ≪Manufacture of Pipe Pillow≫ The pipe pillow 1 of this embodiment can be obtained by melt-kneading the above-described resin composition at a temperature of, for example, 175 to 260°C and then molding it using a mold. The melt-kneading may be performed in the melt-kneading section of a molding machine or separately using a melt-kneading machine. The molding can be carried out by a conventionally known resin molding method such as injection molding, injection compression molding, press molding, blow molding, etc. Since the above resin composition has excellent fluidity, injection molding is preferred. The molding temperature can be, for example, 180 to 220°C. A mold release agent for the mold or a metal component derived from the mold may adhere to the surface of the pipe pillow 1.

[0046] The resin composition of this embodiment preferably has a melt mass flow rate (MFR) measured in accordance with JIS K7210 in the range of 7.0 g / 10 min or more and 18.0 g / 10 min or less. If it is within this range, it is easy to balance the moldability and the strength of the pipe pillow as the molded body. More preferably, the upper limit of the melt mass flow rate (MFR) is 10.0 g / 10 min or less. In the present invention, the melt mass flow rate (MFR) is a value measured at 200°C under a load of 2.54 kg in accordance with JIS K7210-2014.

[0047] Also, the resin composition of this embodiment preferably has an Izod impact strength measured in accordance with JIS K7110 of 4.0 KJ / m 2 or more. If it is within this range, it is easy to obtain sufficient impact strength for the molded body (pipe pillow) in actual use. In the present invention, the Izod impact strength is measured with a notch at 23°C using a test piece obtained by molding the resin composition into a plate shape with a width of 80 mm × 10 mm and a thickness of 4 mm in accordance with JIS K7110-1999.

[0048] Moreover, it is preferable that the resin composition of the present embodiment has a flexural modulus of elasticity of 1000 MPa or more as measured in accordance with JIS K7171. If it is within these ranges, it is easy to obtain sufficient flexural strength in the molded body (pipe pillow) during actual use. In the present invention, the flexural modulus of elasticity is measured at 23°C in accordance with JIS K7171-2016 using a test piece obtained by molding the resin composition into a plate shape with a width of 80 mm × 10 mm and a thickness of 4 mm.

[0049] Since the pipe pillow 1 of the present embodiment is obtained by molding a resin composition made of a container packaging recyclable material, it can contribute to the effective use of resources, and furthermore, it is possible to achieve both moldability and strength in actual use.

[0050] The pipe pillow 1 of this embodiment may have its shape, wall thickness of each part, etc. changed compared to a pipe pillow formed from virgin raw materials or recycled materials with stable other qualities, taking into account the resin components of the container packaging recyclable materials contained in the resin composition and their ratios. For example, considering the shrinkage rate during molding, the wall thickness of part or multiple parts of the pipe pillow 1 may be designed to be different from the corresponding parts of a pipe pillow formed from virgin raw materials or recycled materials with stable other qualities. Since the parts involved in joining adjacent pipe pillows 1 are likely to be affected in the joined state when shrinkage occurs, for example, at least a pair of the protruding pieces (the pair of protruding pieces 24a and 24b in the concave groove 24, the pair of protruding pieces 25a and 25b in the protruding strip 25, the pair of protruding pieces 26a and 26b in the concave groove 26, the pair of protruding pieces 27a and 27b in the protruding strip 27) of the pipe pillow 1 may have a larger wall thickness compared to the wall thickness of a pipe pillow formed from virgin raw materials or recycled materials with stable other qualities. With this configuration, while being a molded product formed from a resin composition made of container packaging recyclable materials, it is easy to favorably adjust the joined state with adjacent pipe pillows 1. In this case, the part where the wall thickness is increased may have its wall thickness increased by, for example, about 3 to 10% compared to the corresponding part of a pipe pillow formed from virgin raw materials or recycled materials with stable other qualities. When comparing with the wall thickness inside the pipe pillow 1 of this embodiment, among the above-mentioned protruding piece parts of the pipe pillow 1, it is also possible to adopt a mode of increasing the wall thickness of the pair of protruding pieces 27a and 27b in the protruding strip 27 compared to the wall thickness of other parts of the pipe pillow 1. With this mode, it is easy to achieve both moldability and stability of the joint part of the pipe pillow 1 in the vertical direction.

[0051] ≪Other Embodiments≫ In the above embodiment, an example of molding the pipe pillow 1 using a resin composition made of container packaging recyclable materials has been described. However, the resin composition is not limited to container packaging recyclable materials and can be a resin composition made of recyclable materials of other plastic waste, etc. Also, as long as the resin composition according to the present invention does not impair the characteristics of the pipe pillow, it is not precluded from containing other components (for example, processing agents, processing aids, etc. as used in normal resin processing) other than those described above.

[0052] In the above embodiment, an example in which the pipe pillow 1 is molded using a resin composition containing polypropylene and polyethylene and capable of containing a chlorine-based resin, polystyrene, and titanium oxide has been described. However, components other than polypropylene and polyethylene are not essential, and the chlorine-based resin, polystyrene, and titanium oxide may not be included.

[0053] In the above embodiment, an example in which the resin composition is in the form of pellets has been described. However, the shape of the resin composition is not limited to pellets and can be other shapes.

[0054] In the above embodiment, an example in which the pipe pillow 1 is molded using the container packaging recyclable material as all of the raw material resin composition has been described. However, it is not limited to this, and the container packaging recyclable material may be used as part of the raw material. For example, it is preferable that 50% by mass or more is molded using the container packaging recyclable material.

[0055] In the above embodiment, the pipe pillow having the shape of FIG. 1 has been described as an example. However, the shape and size of the pipe pillow, the wall thickness of each part, etc. are not limited to this. All or part of the joint portions with other pipe pillows are not necessarily required, and the fitting shape for joining with adjacent pipe pillows is not limited to that of the embodiment. For example, the fitting shapes of the right side surface portion and the left side surface portion, and the fitting shapes of the bottom surface portions may be different. Also, at least one of the fitting shapes of the right side surface portion and the left side surface portion, and the fitting shapes of the bottom surface portions may be a complementary fitting shape without protruding pieces, concave grooves, and ridges.

Examples

[0056] Hereinafter, the pipe pillow of the present embodiment will be described more specifically with reference to examples. However, the scope of the present invention is not limited by the following examples.

[0057] (Resin Composition) First, pellets (resin composition) made of container packaging recyclable materials were prepared. The pellets were obtained by crushing container packaging waste collected as garbage, then sorting materials mainly composed of polypropylene using a multi-sorter, further washing and crushing it, separating other resins by specific gravity, drying, and shaping it into pellet form using a granulator. The pellets had polypropylene as the main component and contained polypropylene at 70 mass% or more, polyethylene at 30 mass% or less, chlorine-based resin at 3 mass% or less, polystyrene at 5 mass% or less, and titanium oxide at 5 mass% or less.

[0058] (Physical properties of the resin composition) The obtained resin composition had a melt mass flow rate (MFR) of 9.9 g / 10 min measured in accordance with JIS K7210. Also, the obtained resin composition was melted at 200 °C, formed into a plate shape, and the Izod impact strength measured in accordance with JIS K7110 was 4.2 KJ / m 2 , and the flexural modulus measured in accordance with JIS K7171 was 1,044 MPa.

[0059] (Manufacture of pipe pillows) The obtained pellets were put into an injection molding machine, melt-kneaded at a temperature of 180 - 190 °C in the screw-type melt-kneading part of the injection molding machine, and then injection molded in the injection molding part provided with a mold for pipe pillows to manufacture five pipe pillows having the shape shown in Fig. 1.

[0060] (Evaluation of pipe pillows) The following evaluations were performed on the obtained pipe pillows. (1) Fitting with other pipe pillows: One pipe pillow was placed in the center, and the other four pipe pillows were fitted and joined to each other around it (on both the left and right sides, the lower part, and the upper part) by the method described above. At that time, it was confirmed whether it was easily fitted and whether it came off after fitting. (2) Compressive strength: Using a universal testing machine ("UH-200kNX" manufactured by Shimadzu Corporation), two pipe pillows were joined and combined vertically with the arc-shaped part 11 of the pipe pillow as the center, and the entire bottom surface part 16 of the two vertically arranged pipe pillows was clamped with a jig, and the compressive force (N) when compressed by 5.8 mm was measured. (3) Drop strength: When the formed pipe pillow was dropped from a height of 1.5 m, it was visually confirmed whether cracks occurred or not.

[0061] (Evaluation results of the pipe pillow) The pipe pillow of the example could be smoothly fitted with four other pipe pillows arranged around it. After fitting, it did not come off even when pulled in the vertical and horizontal directions, and the fitting with the other four pipe pillows was good. That is, it was confirmed that a pipe pillow with good dimensional accuracy could be manufactured and it had excellent formability. Also, the compressive strength measured by the above method was 5852 N, and no cracks occurred when it was dropped from a height of 1.5 m, and it was also excellent in compressive strength and impact strength. From the above, it was confirmed that a pipe pillow that can withstand actual use can be manufactured from the resin composition made of the container packaging recyclable material.

[0062] As described above, the embodiments of the pipe pillow have been described in detail with examples, but the scope of the present invention is not limited to the specific embodiments and examples described above. The embodiments disclosed in this specification are illustrative in all respects, and can be appropriately modified without departing from the spirit of the present invention.

Industrial applicability

[0063] The present invention can be used for pipe pillows that support various pipes such as protection pipes for cables.

Explanation of reference numerals

[0064] 1 Pipe pillow 11 Arc-shaped part 12 Upper right surface part 13 Upper left surface part 14 Right side wall part 15 Left side wall part 16 Bottom surface part

Claims

1. A pipe pillow made of a resin composition containing polypropylene and polyethylene, wherein the proportion of the polypropylene in the resin composition is 70% by mass or more, and the proportion of the polyethylene in the resin composition is 30% by mass or less.

2. The resin composition contains a chlorine-based resin, and the pipe pillow according to claim 1, wherein the proportion of the chlorine-based resin in the resin composition is 3% by mass or less.

3. The resin composition contains polystyrene, and the pipe pillow according to claim 1, wherein the proportion of the polystyrene in the resin composition is 5% by mass or less.

4. The resin composition contains titanium oxide, and the pipe pillow according to claim 1, wherein the proportion of the titanium oxide in the resin composition is 5% by mass or less.

5. The pipe pillow according to any one of claims 1 to 4, wherein the resin composition is a container packaging recyclable material.

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