KR102590223B1 - watertightness reinforced pipe - Google Patents

Abstract

The present invention relates to pipe pipes, and more specifically, to watertight reinforced pipe pipes with improved watertightness.

Description

Watertightness reinforced pipe {watertightness reinforced pipe}

The present invention relates to pipe pipes, and more specifically, to watertight reinforced pipe pipes with improved watertightness.

In general, sewer pipes, water pipes, sewage pipes, waste water pipes, etc. buried underground are buried at a certain depth underground, and considering their installation location, they have a certain degree of ductility and have higher strength, durability, and chemical resistance than pipes exposed to the outside. , water resistance, etc. are required. To meet these needs, pipes made using synthetic resins are widely used to date. Pipes made of synthetic resins have the additional advantage of being able to be used semi-permanently as they do not rust or rot even when exposed to corrosive substances present in the soil. .

For this reason, pipes made of synthetic resin are widely used not only in various industrial fields such as agricultural waterways buried in the ground, sewage pipes for wastewater and rainwater pipes, and industrial piping materials for highly toxic wastewater, but also in everyday life.

For pipes made of synthetic resin, various manufacturing methods and suitable manufacturing equipment have been developed, such as melt-extruding the synthetic resin composition that makes up the pipe using a tubular mold, or extruding it into a sheet with a predetermined width and then wrapping it in a spiral and heat-sealing it. It is done.

In addition, in order to sufficiently demonstrate the watertightness, ductility, impact resistance, and strength of the pipe to be implemented, it is possible to have a structure in the form of a multi-layered pipe where several layers are stacked to form a pipe, or to layer a material that can reinforce mechanical properties. Pipes are implemented by providing them in a matrix.

A currently widely used method for producing such pipes is the spiral method, in which extruded sheet-shaped synthetic resin material is supplied to a winding device in a spiral shape, and the spirally wound synthetic resin material is smoothly molded into a pipe. This method is used. In the case of manufactured pipes, there is a problem of gaps occurring in overlapping areas between wound synthetic resin sheets due to contraction and expansion due to temperature changes in the usage environment after manufacturing. In addition, there is a problem that watertightness is reduced due to cracking or separation in the overlapping area due to external force generated when burying the pipe or load applied after burying the pipe.

Accordingly, there is a problem in that it is not easy to manufacture a pipe with enhanced bonding force and watertightness of the synthetic resin parts that overlap during winding.

Registered Patent Publication No. 10-1612028

The present invention was developed in consideration of the above points, and when manufacturing a pipe through the spiral method, watertightness is maintained through the strengthened bonding force of the overlapping portion of the synthetic resin material despite temperature changes or external forces applied to the pipe. The purpose is to provide improved piping.

In addition, the present invention improves the material of the composite resin material to control the shrinkage characteristics that occur differently depending on the direction during extrusion to achieve high watertightness and improved ductility, impact resistance, and rigidity, and the extruded pipe forming composition is spiral-shaped. Another purpose is to provide a pipe suitable for the spiral method of forming a pipe by winding it.

In order to solve the above-described problem, the present invention is a pipe pipe in which an inner layer, a middle layer, and an outer layer are arranged from a hollow penetrating in a first longitudinal direction to an outer direction perpendicular to the longitudinal direction, wherein the middle layer is an opposing first layer. A first bend and a second bend are bent in opposite directions based on the thickness direction by a predetermined width on each of the side and second side parts, and the first bend is inside the second bend of the intermediate layer forming sheet formed along the longitudinal direction. It provides a watertight reinforced pipe formed by spirally winding the outer peripheral surface of the inner skin layer toward a first direction so that it is inserted to form a joint.

According to one embodiment of the present invention, the intermediate layer forming sheet may be provided with a polyolefin-based matrix containing at least one of polyethylene and polypropylene, and a reinforcing agent containing metal foil flakes dispersed in the polyolefin-based matrix.

According to another embodiment of the present invention, the metal foil flake may be an aluminum foil flake.

According to another embodiment of the present invention, the reinforcing agent may be included in an amount of 25 to 60 parts by weight based on 100 parts by weight of the polyolefin-based matrix.

According to another embodiment of the present invention, the bending angles of the first bending portion and the second bending portion formed in the intermediate layer forming sheet may each independently be 25 to 50°.

According to another embodiment of the present invention, the predetermined width may be formed as a length of 1/10 or more of the width of the intermediate layer forming sheet.

According to another embodiment of the present invention, the reinforcing agent may further include glass fiber.

According to another embodiment of the present invention, a filler contained in an amount of 20 to 50 parts by weight based on 100 parts by weight of a polyolefin-based matrix, and a shrinkage control agent that is a talc powder contained in an amount of 2 to 3.5 parts by weight based on 100 parts by weight of the filler. More may be included.

According to another embodiment of the present invention, the talc powder may have a diameter of 3 to 5 μm.

According to another embodiment of the present invention, the metal foil flake has a first aspect ratio (a/b), which is the ratio to the length (a) and width (b), of 1.5 or more, and the glass fiber has a length (m) And the second aspect ratio (m/n), which is a ratio to the diameter (n), may be 150 or more.

According to another embodiment of the present invention, the glass fiber may have a diameter of 5 to 20 μm and a length of 0.8 to 2.5 mm.

The pipe according to the present invention can greatly improve watertightness as the structural bonding force of the overlapping portion of the reinforced synthetic resin material is strengthened despite temperature changes or external forces applied to the pipe pipe when manufacturing the pipe through the spiral method. there is. In addition, the pipe pipe according to an embodiment of the present invention is advantageous in fully expressing structural bonding force as the shrinkage characteristics in the manufacturing process are controlled due to material improvements in synthetic resin materials, and thus has higher watertightness, improved ductility, Because it can exhibit impact resistance and rigidity, it can be widely used as pipes buried underground, such as sewer pipes, water pipes, sewage pipes, and waste water pipes.

Figure 1 is a cross-sectional perspective view of a pipe according to an embodiment of the present invention.
Figure 2 is a perspective view and a cross-sectional view along the XX' boundary line of an intermediate layer forming sheet used in the pipe manufacturing process according to an embodiment of the present invention.
Figure 3 is a schematic diagram of forming an intermediate layer when manufacturing a pipe according to an embodiment of the present invention and a cross-sectional schematic diagram of the overlapping portion of the intermediate layer forming sheet along the YY' boundary line.
Figure 4 is a schematic diagram of a manufacturing apparatus for manufacturing a pipe according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention.

Figure 1 is a cross-sectional perspective view of a watertight reinforced pipe 100 according to an embodiment of the present invention, from a hollow (P) penetrating in a first longitudinal direction (d1) to an outer direction (d2) perpendicular to the longitudinal direction. ) is implemented by arranging the inner layer 10, the middle layer 20, and the outer layer 30.

The intermediate layer 20 constitutes the body of the pipe and functions to give the shape and mechanical properties of the pipe. The intermediate layer 20 can be made of any material forming the middle layer of a synthetic resin pipe pipe without limitation. For example, the polyolefin-based matrix forming the body and mechanical strength, such as flexural elasticity, flexural strength, tensile strength, and impact strength, etc. Reinforcing agents may be included to improve mechanical properties.

In addition, the inner layer 10 is disposed on the inner side of the above-described middle layer 20 in the hollow (P) direction, and the outer layer 30 is disposed on the outer side. The inner layer 10 and the outer layer 30 supplement the watertightness and mechanical strength of the pipe, and physically and chemically protect the middle layer 20 from the liquid flowing through the hollow P and the external environmental conditions in which the pipe is buried. It functions as a protective layer.

The inner layer 10 and the outer layer 30 may be made of any material that typically forms the inner and outer surfaces of the pipe, and may be made of polyolefin-based resin, which is the same material as the body of the middle layer. , More preferably, the middle layer 20, the inner layer 10, and the outer layer 30 are formed of the same material in consideration of adhesion and bonding characteristics at the interfaces formed respectively.

Meanwhile, the thickness of the inner layer 10, the middle layer 20, and the outer layer 30 is the thickness of each layer in a typical pipe having a three-layer structure in consideration of the inner diameter of the pipe to be implemented and the required physical properties. Since the can be adopted or modified appropriately, the present invention is not particularly limited thereto.

The pipe 100 according to an embodiment of the present invention is manufactured through a spiral method known as a pipe manufacturing method. Specifically, the middle layer 20 is formed after the middle layer forming composition forming the middle layer 20 is introduced into the compressor. The middle layer forming sheet 20a, which is melt-extruded and then extruded, is formed by being wound in a spiral shape so as to be in close contact with the outer peripheral surface of the inner skin layer 10. At this time, the middle layer 20 is formed by winding the sides of the middle layer forming sheet 20a so that they overlap by a predetermined width.

However, even if the intermediate layer is realized by simply winding the overlapped region and then flattening the thickness of the overlapped region, the expansion and contraction due to heat of the intermediate layer forming sheet 20a causes lifting at the interface between the intermediate layer forming sheets 20a in the overlapped region. However, there is a problem that the area of the overlapping area decreases due to shrinkage or causes unevenness, thereby lowering watertightness.

While continuously researching this problem, the inventors of the present invention formed a bend corresponding to a structural bonding means in the middle layer forming sheet 20a to add physical bonding between the bends to the overlapped area to prevent lifting at the interface within the overlapped area. This led to the present invention by solving the problems of watertightness reduction, impact, and strength reduction caused by such factors.

Specifically, as shown in FIG. 2, the middle layer forming sheet 20a has a first bending portion 20a ₁ and a second bending portion 20a ₂ corresponding to structural coupling means in the longitudinal direction of the middle layer forming sheet 20a. Accordingly, it is formed, and the first bent portion (20a ₁ ) and the second bent portion (20a ₂ ) have a predetermined width (w ₁ , w) so that the directions are opposite to each other based on the thickness direction of the intermediate layer forming sheet 20a. ₂ ) is bent.

The intermediate layer forming sheet 20a having this structure is wound spirally along the first direction (d ₁ ) on the outer peripheral surface of the inner skin layer 10, as shown in FIG. 3. At this time, the second bent portion 20a ₂ As the first bent portion 20a ₁ is inserted into the inside and wound to form the coupling portion B, the intermediate layer forming sheet 20a is not simply an overlapping side part, but also a coupling part in which the sides are structurally fastened to each other. By forming (B), even if the expansion and contraction of the middle layer occurs due to heat, the occurrence of gaps in the overlapped area or breakage or cracks due to external force can be minimized.

In addition, the first bent portion 20a ₁ and the second bent portion 20a ₂ may each have a bending angle (θ ₁ , θ ₂ ) of 25 to 50°, more preferably 35° to 50°, If the bending angle is less than 25°, it may be difficult to insert the first bent part (20a ₁ ) into the second bent part (20a 2) during the spiral winding process, and if the bending angle exceeds 50°, the second bent part (20a ₁ ) may be inserted into the second bent part (20a 2). After the first bent part (20a ₁ ) is inserted into the bent part (20a ₂ ), a coupling failure may occur in which the first bent part (20a ₁ ) is easily separated from the inside of the second bent part (20a ₂ ) and wound. There is great concern. On the other hand, even if such a coupling defect occurs, the first bent part overlaps the second bent part, so the overlap itself does not become a defect, and an intermediate layer can be formed as in the case where the bent part does not exist. However, due to poor coupling, it may not be possible to achieve great watertightness, and in particular, the pipe pipe may be long-term due to contraction or expansion of the middle layer due to seasonal temperature changes or temperature changes of the liquid flowing inside the pipe pipe. There is a risk that a very large difference may occur in water pressure resistance characteristics.

In addition, the width at which the first bent portion 20a ₁ and the second bent portion 20a ₂ are bent may have a length of 1/10 or more of the width of the middle layer forming sheet 20a, and in another example, 1/5 or less. It is good to have a length of . If the bending width is less than 1/10 of the width of the middle layer forming sheet 20a, the first bent part _{20a 1} is easily inserted into the inside of the second bent part 20a ₂ . There is a high risk that a defective connection may occur where the second bend part 20a ₂ deviates from the inside and winds up. In addition, if the bending width exceeds 1/5 of the width of the middle layer forming sheet 20a, the improvement in bonding strength due to the increase in the overlapped area during winding is minimal, and rather, the first bending force is moved to the inside of the second bent portion 20a ₂ . It may be difficult to insert the bent portion (20a ₁ ).

Describing the intermediate layer forming sheet 20a in detail, the polyolefin-based matrix forms the body of the intermediate layer and is formed by including a typical polyolefin-based resin used in pipes. Here, inclusion as a subject means more than 80% by weight of the resin forming the matrix, as an example, more than 85% by weight, as another example, more than 90% by weight, or more than 95% by weight.

The polyolefin-based resin may include one or two or more types such as polyethylene, polypropylene, polybutene, ethylene vinyl acetate copolymer, and ethylene-◎olefin copolymer. Preferably, in terms of strength and improvement in elongation at high temperatures, it may be polyethylene and/or polypropylene, more preferably it may contain polyethylene, and even more preferably may be made of polyethylene.

The polyethylene (PE) may be one or more of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE). In addition, polypropylene (PP) may include homo polypropylene, block polypropylene, etc. Moreover, examples of polybutene include polybutene-1. Ethylene-◎olefin copolymer is a copolymer in which ◎olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, or 1-octene are copolymerized with respect to ethylene in a ratio of about several mole percent. A chain is preferable.

Meanwhile, when polyethylene is preferably used, it is better to use polyethylene with an average degree of polymerization of 800 to 1,000. If polyethylene with a degree of polymerization of less than 800 is used, there is a risk of a decrease in tensile strength, and if polyethylene with a degree of polymerization of more than 1,000 is used, there is a risk of a decrease in processability.

Next, the reinforcing agent dispersed in the polyolefin matrix may be used without limitation if it is a typical reinforcing agent used to reinforce the strength of pipes, but the present invention provides increased impact resistance, flexural elasticity, flexural strength, tensile strength, and rigidity. To achieve this, metal foil flakes may be included as a reinforcing agent, and glass fibers may be further included to achieve synergy of these effects.

The metal foil flakes are made by cutting and pulverizing metal foil into predetermined sizes and play a role in increasing the ductility and impact resistance of pipes. The metal foil flakes can be used without limitation in the case of known metal foils, but are preferably aluminum foil flakes, which provide a synergistic effect with glass fiber compared to the case of using metal foil flakes of other materials. It is advantageous.

The thickness of the metal foil flake may be that of a commonly commercialized metal foil, and the present invention is not particularly limited thereto. In addition, the metal foil flakes may have an amorphous shape, but are preferably cut and pulverized to have a length longer than the width in one direction, and more preferably have a ratio to the length (a) and width (b). It may be cut and pulverized so that the first aspect ratio (a/b) is 1.5 or more, more preferably 2.0 or more, and even more preferably 2.0 to 10.0, and through this, ductility and impact resistance are improved. In addition, it can be advantageous to develop increased flexural modulus, tensile strength, etc. in combination with glass fiber, which will be described later.

Meanwhile, the metal foil flakes may be made from commercialized metal foil itself, but may be derived from metal foil film waste used as packaging material in terms of resource recycling. The metal foil film is a multi-layer laminated film layer of polyethylene terephthalate, polyethylene, polypropylene, etc., and a metal foil layer, and is a typical metal foil film used for packaging various foods, electronic components such as semiconductors, and electronic devices. It can be used without restrictions.

Additionally, glass fiber may be further included as a reinforcing agent along with the metal foil flakes. The glass fiber significantly improves the mechanical strength of the pipe implemented by using only metal foil flakes as a reinforcing agent, and in particular has an increased effect on impact resistance, tensile strength, and flexural modulus. The glass fibers can be used without limitation in the case of glass fibers that typically function as reinforcing agents in polymer resins. For example, they may have a composition classified as E-class or S-class in the art, and the present invention specifically addresses this. It is not limited.

In addition, the glass fiber preferably has a second aspect ratio (m/n), which is the ratio to the length (m) and diameter (n), of 150 or more, more preferably 200 or more, and in another example, 600 or less, more preferably may be 450 or less. If glass fibers with a second aspect ratio of less than 150 are provided, it is difficult for the glass fibers to be oriented in a spirally wound direction during the process of forming the intermediate layer through the spiral method, and there is a risk that sufficient mechanical strength may not be achieved due to this. In addition, when the aspect ratio exceeds 600, there is a risk that some elements penetrate the outer surface of the middle layer and the orientation within the matrix may deteriorate.

In addition, the glass fiber may have a diameter of 5 to 20㎛ and a length of 1.2 to 5.0㎜, through which the glass fiber forms an intermediate layer while being perpendicular to any one direction within the intermediate layer, for example, the thickness direction of the intermediate layer. It is advantageous for the intermediate layer forming sheet to be oriented in a spirally wound direction, and through this, higher mechanical properties can be achieved. If the length of the glass fiber exceeds 5.0 mm, there is a high possibility that the glass fiber will not be oriented along the spiral winding direction during the process of forming the middle layer through the spiral method, and one end will protrude outward through the outer surface of the middle layer. This may make it difficult to achieve sufficient mechanical strength, such as impact resistance. In addition, if the length of the glass fiber is less than 1.2 mm, it is difficult to orient the glass fiber in any one direction, specifically parallel to the direction in which the middle layer forming sheet is wound and perpendicular to the thickness direction of the middle layer, and as a result, mechanical strength such as tensile strength decreases. may deteriorate.

Meanwhile, as a reinforcing agent, it may further contain a different type of fibrous reinforcing agent other than glass fiber. The heterogeneous fibrous reinforcing agent may be, for example, carbon fiber, synthetic resin fiber, and cellulose-based fiber, and the present invention is not particularly limited thereto.

In addition, the above-described reinforcing agent may be included in an amount of 25 to 60 parts by weight, more preferably 35 to 50 parts by weight, based on 100 parts by weight of the polyolefin-based matrix. If the reinforcing agent is contained in less than 25 parts by weight, the supplementation of mechanical strength through the reinforcing agent may be minimal. In addition, when the reinforcing agent exceeds 50 parts by weight, the impact resistance of the middle layer decreases, and there is a high risk of damage such as cracks. In addition, during extrusion, there is a risk of excessive shrinkage in the TD direction perpendicular to the MD direction, which is the direction in which the molten intermediate layer forming composition flows through the injection port, and the content of talc powder, which will be described later, is relatively reduced, resulting in excessive shrinkage in the TD direction. Control can be difficult.

Meanwhile, when metal foil flakes and glass fibers are used together as reinforcing agents, they can be mixed at a weight ratio of 1: 3 to 5, which can be more advantageous in achieving the purpose of the present invention.

According to one embodiment of the present invention, the intermediate layer forming sheet 20a may further include a filler and a shrinkage control agent such as talc powder.

The filler is included to improve the hardness and durability of the pipe and reduce production costs. Known fillers used in pipes can be used without limitation, but preferably one of calcium carbonate and hydrotalcite. Or a mixture thereof may be included. When using calcium carbonate or hydrotalcite, if the above-mentioned metal foil flakes are derived from metal foil film waste, it is necessary to prevent a decrease in strength due to mixing of the polymer film materials that make up the metal foil film, which may inevitably be included in the polyolefin matrix. It may be more advantageous.

Meanwhile, the filler may be included in an amount of 20 to 50 parts by weight based on 100 parts by weight of the polyolefin-based matrix. If the filler is contained in less than 20 parts by weight, the effect achieved through the above-mentioned filler may be minimal. Additionally, if the filler exceeds 50 parts by weight, the content of matrix components, reinforcing agents, etc. may be relatively reduced, making it difficult to achieve the purpose of the present invention.

In addition, the shrinkage control agent, which is the talc powder, functions to improve the shrinkage rate deviation that occurs when the reinforcing agent is contained, especially the shrinkage rate deviation and low smoothness that occur after the intermediate layer forming composition containing glass fiber is melted and extruded. As described above, the intermediate layer forming sheet 20a according to the present invention has a first bend and a second bend in the width direction, and excessive and/or uneven shrinkage occurring in the width direction causes the first bend and the second bend. It can make it difficult to form the bent portion uniformly, and even when structurally inserted and coupled between them, it can make it difficult to form a stable coupling portion (B). Accordingly, when the middle layer forming sheet 20a further includes glass fiber as a reinforcing agent, it may be difficult to implement a pipe with high watertightness even when there is a bend due to the variation in shrinkage rate and low smoothness of the middle layer that occurs during the pipe manufacturing process. there is.

Specifically, the glass fiber with a large second aspect ratio is generally oriented so that the machine direction (MD) in which the intermediate layer forming composition is extruded is the longitudinal direction of the glass fiber when the intermediate layer forming composition is extruded. This has the advantage of greatly preventing shrinkage in the MD direction. This causes a problem in which shrinkage in the TD direction becomes even larger. In this case, in the process of manufacturing the middle layer by extruding it to have a predetermined width and then winding it in a spiral shape, the overlapping area on the side of the middle layer forming sheet becomes uneven, and the middle layer becomes unstable. Due to the reduced smoothness of the formed sheet, there are parts in the overlapped area that are not in close contact, which may cause the side effect of lowering the watertightness of the formed intermediate layer. However, when talc powder is added as a shrinkage control agent, both the TD direction shrinkage and the thickness direction shrinkage of the middle layer forming sheet are controlled, and this can increase the uniformity of the bends, creating a more water-tight middle layer after the bends are joined. It can be advantageous to form.

However, the talc powder used as a shrinkage control agent may have a diameter of 3 to 5㎛, and if it contains large-sized talc powder exceeding 5㎛ in diameter, it is difficult for the talc powder to act as a nucleating agent, so it functions as a filler instead. There is a risk that it may not function as a contraction control agent. Additionally, if the diameter of the talc powder is less than 3㎛, it may be difficult to control the smoothness and shrinkage characteristics to the desired level.

The shrinkage control agent, which is the talc powder, may be contained in an amount of 2 to 3.5 parts by weight based on 100 parts by weight of the filler, which may be more advantageous in achieving the purpose of the present invention. If the shrinkage control agent is contained in less than 2 parts by weight, the shrinkage control effect may be minimal, and if it exceeds 3.5 parts by weight, there is a risk that impact resistance may be reduced.

Meanwhile, other than the above-mentioned talc powder, ingredients such as silica, mica, calcium carbide, and titanium dioxide may not be suitable as shrinkage control ingredients, and in particular, even when they have the same particle size as the above-mentioned, they do not exhibit a shrinkage control effect at the level of talc. It can be difficult.

According to one embodiment of the present invention, in addition to the above-mentioned components, the intermediate layer 20 contains known additives contained in pipes such as impact modifiers such as rubber resins, stearic acid to suppress cracks, and dispersants such as citrate. It may be further provided, and detailed description and examples thereof are omitted in the present invention.

The pipe 100 according to an embodiment of the present invention described above can be manufactured through a pipe manufacturing apparatus described below. Referring to FIG. 3, the pipe manufacturing apparatus includes an intermediate layer extruder 1000 that melts and extrudes the intermediate layer forming composition, and is in close contact with the inner peripheral surface of the intermediate layer formed by extrusion from the intermediate layer extruder 1000 to extrude the inner layer. It is configured to include an inner layer extruder (2000) and an outer layer extruder (2100) that extrudes the outer peripheral surface of the middle layer in close contact to form an outer layer.

The middle layer extruder 1000 includes a primary crushing melter 1100 in which waste metal foil film is first crushed and melted to produce metal foil flakes as a reinforcing agent, and a primary crushing melter 1100 that flows in from the primary crushing melter 1100. It is configured to include a secondary melter (1200) that secondarily melts recycled materials. Although not shown in the drawing, each input means for the polyolefin matrix component and additional reinforcing agents such as glass fiber as a reinforcing agent is connected to the primary crushing melter 1100, so that melting can be achieved by mixing with the pulverized waste metal foil film. there is.

In addition, the intermediate layer forming composition melted in the secondary melter 1200 flows into the hopper-shaped distribution box 1118 and is extruded downward while rotating the tensioner 4000 located below the distribution box 1118. It can be wound around the roller 4300 in layers. The tensioner 4000 is provided with a rotating roller 4300 rotated by a motor, and the rotating roller 4300 is formed of a plurality of rollers.

In addition, the inner skin layer extruder 2000 is for melting and extruding synthetic resin raw materials, and is formed with a raw material inlet 2020 for introducing the inner skin layer forming composition, and heats the input composition to melt it so that it can be extruded. The raw material heated to around ℃ and melted is transferred to the tensioner 4000 to attach the extrusion die or guide, and a detailed description of the inner layer extruder 2000 will be omitted.

In addition, the outer skin layer extruder 2100 is for melting and extruding the outer skin layer forming composition like the inner skin layer extruder 2000. A raw material inlet 2020 is formed for introducing the outer skin layer forming composition, and the input raw material is heated and extruded. It is composed of a body 2121 that is heated before and after 200°C and transfers the molten plastic raw material to the tensile machine 4000 in order to melt it. At the end of the body 2121, the raw material is transferred to the tensile machine 4000. An outer layer discharge pipe 220 may be formed to discharge.

The inner skin layer forming sheet, outer skin layer forming sheet, and middle layer forming sheet 20a extruded through the inner skin layer extruder 2000, outer skin layer extruder 2100, and middle layer extruder 1000 are used to form an inner skin layer inside the extruded middle layer forming sheet. The sheets are extruded in a spiral manner so as to be in close contact with each other, and the outer shell layer forming sheet is extruded in a spiral manner so as to be in close contact with the outside of the middle layer forming sheet, and then bonded at the interface of each extruded sheet to form an integrated pipe tube (100).

More specifically, in the process of first winding the inner skin layer forming sheet in a spiral manner in a first direction so as to have a hollow with a predetermined diameter on the inside, the middle layer forming sheet is wound spirally in the first direction to the outside of the wound inner skin layer forming sheet to form an intermediate layer. Can be formed, and in the process of forming the middle layer, the outer skin layer forming sheet may be spirally wound in a first direction outside the middle layer forming sheet to form the outer skin layer. At this time, the formation process of the inner, middle, and outer layers may begin at a predetermined time interval, but is not limited to this, and includes cases where the middle layer is formed after the inner layer is completely formed, and the outer layer is formed after the middle layer is completely formed. Let it be known.

The present invention will be described in more detail through the following examples, but the following examples do not limit the scope of the present invention, and should be interpreted to aid understanding of the present invention.

<Example 1>

A polyethylene resin was prepared with an inner skin layer forming composition and an outer skin layer forming composition. In addition, as an intermediate layer forming composition, 45 parts by weight of reinforcing agent, which is aluminum foil flakes (A) cut and pulverized so that the first aspect ratio is 2.0 to 3.5, is mixed with 100 parts by weight of polyethylene resin with a degree of polymerization of 950, and 100 parts by weight of polyethylene resin. With respect to 38 parts by weight of calcium carbonate filler, 5 parts by weight of MBS impact modifier, 0.03 parts by weight of stearic acid, and 3.0 parts by weight of talc powder with an average particle diameter of 3.8㎛ as a shrinkage control agent for 100 parts by weight of the filler, and Prepared by mixing. Afterwards, the prepared composition was put into the inner layer extruder, middle layer extruder, and outer layer extruder of the manufacturing equipment shown in Figure 3 to manufacture the pipe pipe using the spiral method. At this time, the outer diameter of the pipe was 265 mm, the thickness was 25 mm, and the thicknesses of the inner layer, middle layer, and outer layer were 1:4.5:1. At this time, the middle layer forming sheet was sized from the ends of both sides to the inside of the width of the middle layer forming sheet. Each side is 5 mm wide, corresponding to 1/10 of the length, and is extruded in a bent form with a bending angle of 35° in the direction opposite to the thickness direction, and is wound spirally in the first direction on the inner layer. A pipe was manufactured by winding the pipe so that the first bend was inserted inside the second bend formed in .

<Examples 2 to 5>

It was manufactured in the same manner as in Example 1, but the bending angle of the bending part of the middle layer forming sheet was changed as shown in Table 1 below to manufacture a pipe as shown in Table 1 below.

<Comparative Example 1>

A pipe was manufactured in the same manner as in Example 1, except that no bends were formed in the middle layer forming sheet, and the overlapping width was 5 mm.

<Experimental example>

For the pipes according to Examples 1 to 5 and Comparative Example 1, the long-term water resistance strength was measured according to the long-term water resistance strength measurement of thermoplastic plastic pipes according to the KPS M 2009 test method, and the measured value of Comparative Example 1 was set as 100. The measured values of each example were converted into relative values and shown in Table 1 below.

In addition, the pipes manufactured through Examples 1 to 5 and Comparative Example 1 were left in a constant temperature and humidity room at a relative humidity of 85RH% and a temperature of 50°C for 480 hours, and then left in a constant temperature and humidity room at a relative humidity of 45RH% and -5°C for 250 hours. After taking out the specimen after 24 hours at room temperature, measure the long-term water resistance strength according to the long-term water pressure strength measurement using the same method, and then convert the measured values of each example into relative values based on the measured value of Comparative Example 1 as 100. It is shown in Table 1 below.

middle layer forming sheet Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 matrix Material/content
(part by weight) PE/100 PE/100 PE/100 PE/100 PE/100 PE/100 adjuvant Aluminum foil flakes (aspect ratio) 2.0 ~ 3.5 2.0 ~ 3.5 1.0 ~ 1.3 2.0 ~ 3.5 2.0 ~ 3.5 2.0 ~ 3.5 Content (parts by weight) 45 45 45 45 45 45 bending part
((Length (mm), bending angle (°)) 1st bend 5/35 5/25 5/18 5/50 5/60 doesn't exist 2nd bending section 5/35 5/25 5/18 5/50 5/60 doesn't exist Properties
(%) Long-term hydraulic pressure strength 121.3 118.2 110.9 119.7 114.4 100 Long-term hydraulic pressure strength after contraction and expansion 184.5 160.0 125.2 178.8 138.9 100

As can be seen through Table 1,

Compared to the pipe according to Comparative Example 1, which does not have a bend but has an overlapping intermediate layer, the pipe according to the embodiment formed by inserting and joining the bends with bends on both sides in the width direction has a greater water pressure resistance. You can see that

However, in the case of Examples 3 and 5, where the bending angle of the bending portion does not fall within the preferred range of the present invention, the water pressure resistance strength is smaller than that of the remaining examples, and in particular, the long-term water pressure resistance strength is greater after contraction and expansion through heating and cooling. It can be seen that this has been reduced, and if the bent part is not formed at the desired bending angle, there may be a part where the first bent part is not properly inserted inside the second bent part during the spiral winding process, or the part may come off and join even after insertion. It is expected that parts that are damaged have occurred and this has caused a difference in the strength of water resistance.

<Example 6>

It was manufactured in the same manner as in Example 1, except that glass fiber (B) with a second aspect ratio of 208 (average diameter 10㎛, average length 2.08mm) was mixed with aluminum foil flakes as a reinforcing agent at a weight ratio of 1:3. Pipe pipes were manufactured with modifications.

<Example 7>

A pipe was manufactured in the same manner as in Example 6, except that the shrinkage control agent was not included as shown in Table 2 below.

<Experimental Example 1>

For the pipes manufactured through Examples 1 and 6 to 7, the stiffness according to the KPS M 2009 test method and the tensile strength according to the ASTM D 638 test method were measured, and the measured value of Example 1 was measured as 100. The measured values in Examples 6 and 7 were converted to relative values and shown in Table 2 below.

In addition, the middle layer forming composition used in Examples 1 and 6 to 7 was added in the same amount to the same set middle layer extruder and then wound on a predetermined roller at the same speed. Afterwards, measure the width of a total of 50 points at 5cm intervals in the length direction starting from a point 5cm (measurement start point) from one end of the wound middle layer in the longitudinal direction, and then calculate the width average and standard deviation for the measurements at 50 points. Afterwards, width uniformity was calculated according to the formula below to evaluate whether shrinkage occurred evenly. The closer the width uniformity value is to 0%, the more uniform the shrinkage occurs.

Width uniformity (%) = [50 points width standard deviation (cm) / 50 points average width (cm)] × 100

Example 6 Example 7 Example 1 matrix Material/content (part by weight) PE/100 PE/100 PE/100 adjuvant A aspect ratio 2.0 ~ 3.5 2.0 ~ 3.5 2.0 ~ 3.5 B aspect ratio 208 208 Not included A:B weight ratio 1:03 1:03 - Content (parts by weight) 45 45 45 Contraction control agent Material/average particle diameter (㎛)/content (parts by weight) Talc/3.8/3.0 Not included Talc/3.8/3.0 Shrinkage characteristics Width uniformity (%) 2.4 32.5 2.4 mechanical properties hardness(%) 175.0 124.4 100 tensile strength(%) 562.5 342.3 100

As can be seen in Table 2,

In the case of Examples 6 and 7 containing glass fiber, the mechanical properties can be significantly improved compared to Example 1 containing only aluminum foil, but as can be seen from the comparison between Example 6 and Example 7, due to the inclusion of glass fiber It can be seen that this can cause width unevenness in the width direction.

However, in the case of Example 6, where talc powder with an average particle diameter of 3.5 ㎛ or more as a shrinkage control agent is provided, the width unevenness in the width direction is significantly reduced compared to Example 7, and through this, bends are formed on both sides in the width direction through the spiral method. The bonding portion formed by spirally winding the formed intermediate layer forming sheet so that the first bending portion is inserted and bonded to the inside of the second bending portion is formed more uniformly in Example 6 than in Example 7, and the bonding defect is significantly greater due to width unevenness due to shrinkage. It can be expected that it will decrease.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiment presented in the present specification, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same spirit. , other embodiments can be easily proposed by change, deletion, addition, etc., but this will also be said to be within the scope of the present invention.

Claims (9)

A pipe pipe in which an inner layer, a polyolefin-based middle layer, and an outer layer are arranged from a hollow penetrating in a first longitudinal direction to an outer direction perpendicular to the longitudinal direction,
The intermediate layer has a length of first and second bent parts independently bent at a bending angle of 25 to 50° in opposite directions based on the thickness direction by a predetermined width on each of the opposing first and second sides. It is formed by spirally winding the outer peripheral surface of the inner skin layer toward the first direction so that the first bend is inserted into the second bend of the intermediate layer forming sheet formed along the direction to form a joint,
The intermediate layer forming sheet includes a polyolefin-based matrix;
A reinforcing agent containing aluminum foil flakes and glass fibers dispersed in the polyolefin-based matrix;
A filler that is one of calcium carbonate, hydrotalcite, or a mixture thereof; and
A watertight reinforced pipe containing a shrinkage control agent, which is talc powder. According to paragraph 1,
The polyolefin-based matrix is a watertight reinforced pipe containing at least one of polyethylene and polypropylene. delete According to paragraph 1,
A watertight reinforced pipe containing the reinforcing agent in an amount of 25 to 60 parts by weight based on 100 parts by weight of the polyolefin-based matrix. delete According to paragraph 1,
A watertight reinforced pipe pipe in which the predetermined width is formed to be at least 1/10 of the width of the middle layer forming sheet. delete According to paragraph 1,
A watertight reinforced pipe containing 20 to 50 parts by weight of filler based on 100 parts by weight of the polyolefin-based matrix, and 2 to 3.5 parts by weight of talc powder, a shrinkage control agent, based on 100 parts by weight of the filler. According to paragraph 1,
The talc powder is a watertight reinforced pipe with a diameter of 3 to 5㎛.

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