KR102123098B1 - Method for manufacturing eco-friendly composite pipe and pipe thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing an eco-friendly composite pipe and its pipe, and more specifically, to apply a polyurethane resin in place of the resins used in the past, thereby reducing harmfulness, improving productivity and reducing product weight. Provided is a method for manufacturing a composite pipe and a pipe.

Description

Manufacturing method of eco-friendly composite pipe and its pipes{METHOD FOR MANUFACTURING ECO-FRIENDLY COMPOSITE PIPE AND PIPE THEREOF}

The present invention relates to a method for manufacturing an eco-friendly composite pipe and its pipe, and more specifically, to apply a polyurethane resin in place of the resins used in the past, thereby reducing harmfulness, improving productivity and reducing product weight. It relates to a method of manufacturing a composite pipe and the pipe.

In general, a composite material refers to a composite formed by impregnating a thermosetting resin with a reinforcing material such as glass fiber or carbon fiber through curing by heat with a curing agent. Typical resins of the thermosetting resins include unsaturated polyester resin (UP), And vinyl ester resins (VE) and epoxy resins (EP).

Korean Patent Publication No. 10-2014-0103708 discloses a composite pipe and a composite roller. In the above document, a cylindrical inner pipe made of a reinforcing fiber impregnated with a thermosetting resin; And a composite pipe comprising a prepreg layer formed by impregnating a thermosetting resin in a fabric in which reinforcing fibers are arranged. Korean Patent Publication No. 10-2016-00070859 discloses a method for manufacturing a composite material for a filament winding pipe and a method for manufacturing a pipe for filament winding using the same. This document discloses a method for preparing a composite material in which a reaction modifier is added to and mixed with a peroxide as a resin and a polymerization initiator.

However, as disclosed in the above documents, the thermosetting resin used in the production of composite materials has a problem of harmfulness. For example, the unsaturated polyester resin contains an excessive amount (about 50%) of styrene monomer, which may cause fires due to harmful volatile organic compounds (VOC), and initiate polymerization when curing the unsaturated polyester resin and vinyl ester resin. MEKPO (Methyl Ethyl Ketone Peroxide), which is used a lot, is very irritating to the skin, so it is not only harmful to workers, but also has to be handled very carefully when discarding. And in the case of epoxy resin, there is a problem that bisphenol, a carcinogen, is used for the resin.

Korean Registered Patent No. 0591732 Korean Patent Publication No. 10-2017-0143044

An object of the present invention is to provide a method for manufacturing an eco-friendly composite pipe with significantly reduced harmfulness and a pipe thereof by replacing the resin used in the manufacture of the composite pipe with a polyurethane (PU) resin.

The present invention is also economical burden by forming one or more reinforcing ribs on the outer periphery of the pipe, which not only has excellent self-strength and bending stiffness, but also improves durability, thereby prolonging the life of the pipe, thereby delaying the pipe replacement time An object of the present invention is to provide a method for manufacturing an eco-friendly pipe and a pipe capable of reducing the amount.

In order to achieve the above object, an example of the present invention includes the steps of (a) releasing the surface of a mandrel; (b) Winding with a C-glass mat and a stitch mat impregnated with a polyurethane resin mixture on the outer periphery of the mandrel by a filament winding method, followed by a net net (Net) Defoaming with; (c) forming a liner layer by defoaming and curing the wound C-glass mat and stitch mat layer; (d) winding a continuous fiber impregnated with a polyurethane resin mixture on an outer periphery of the liner layer by a filament winding method; And (e) curing the wound continuous fibers to form a reinforcing layer.

In addition, another example of the present invention provides an eco-friendly composite pipe manufactured by the manufacturing method, which is a method of manufacturing an eco-friendly composite pipe.

The method for manufacturing the eco-friendly composite material of the present invention reduces the harmfulness by using a polyurethane resin and applying a reinforcing rib in place of the resins used in the prior art, thereby eliminating the need for an explosive peroxide required for curing and shortening the curing time. And productivity improvement and weight reduction of the product.

In addition, the eco-friendly composite pipe of the present invention, the reinforcement rib is formed on the outer periphery, while maintaining the flexural strength, the strength of the pipe itself to withstand when a load is applied from the outside can be increased.

1 is a flow chart for explaining a method of manufacturing an eco-friendly composite pipe according to an example of the present invention.
2 is a cross-sectional view of an eco-friendly composite pipe according to an embodiment of the present invention,
3 is a perspective view of an eco-friendly composite pipe according to an example of the present invention.

Hereinafter, the present invention will be described in detail.

1 is a flow chart for explaining a method of manufacturing an eco-friendly composite pipe according to an example of the present invention, FIG. 2 is a cross-sectional view of an eco-friendly composite pipe according to an example of the present invention, and FIG. 3 is according to an example of the present invention It is a perspective view of an eco-friendly composite pipe.

A method of manufacturing an eco-friendly composite pipe according to an example of the present invention includes: (a) releasing the surface of a mandrel; (b) by the filament winding method, the outer periphery of the mandrel is wound with a C-glass mat and a stitch mat impregnated with a polyurethane resin mixture and then defoamed into a net net; (c) forming a liner layer by defoaming and curing the wound C-glass mat and stitch mat layer; (d) winding a continuous fiber impregnated with a polyurethane resin mixture on an outer periphery of the liner layer by a filament winding method; And (e) curing the wound continuous fibers to form a reinforcing layer.

However, the manufacturing method of the eco-friendly composite pipe of the present invention is not limited to the following manufacturing method, and the steps of each process may be modified or optionally mixed as necessary.

Hereinafter, a method of manufacturing the eco-friendly composite pipe 100 according to the present invention and its pipes will be described in more detail with reference to FIGS. 1 to 3 as follows.

[Method of manufacturing eco-friendly composite pipes]

As shown in FIG. 1, in order to manufacture an eco-friendly composite pipe, the surface of the mandrel is first molded (S101).

For example, the surface of the mandrel is formed by winding a PET release film on the surface of the mandrel or forming a release coating film formed of a self-assembled monolayer (SAM) on the surface of the mandrel. Release process.

Then, on the outer periphery of the molded mandrel, wind it by a filament winding method with a C-glass mat and a stitch mat impregnated with a polyurethane resin mixture and defoam into a net net (S103, S105). ).

To this end, prior to winding the filament, a resin supply tank in which polyurethane resin is mixed must be prepared in advance.

Here, the polyurethane resin mixture may include the main portion A and the curing agent portion B in a mixing ratio of 1:1 to 1:1.5.

The main part A contains a polyol component, and it is preferable to mix 60 to 80% by weight of polyol having a molecular weight (M/W) of 200 to 350 and 20 to 40% by weight of castor oil. It is not limited to this.

In addition, the curing agent portion B includes an isocyanate-based curing agent, and it is preferable to use a modified MDI (Methylene Di-para-phenylene Isocyanate). For example, an aromatic isocyanate is used in the formation of the liner layer, and a non-yellowing-type aliphatic isocyanate is used in the formation of the reinforcing layer, whereby an effect of preventing yellowing can be obtained.

In addition, the polyurethane resin mixture is excellent in impregnation and adhesion to C-glass mats, stitch mats, and continuous phase glass fibers, thereby increasing the glass fiber content. Specifically, in the case of an unsaturated polyester resin, the glass fiber content is up to 60%, whereas in the case of a polyurethane resin, the glass fiber content is up to 75%.

As described above, in the present invention, by using a polyurethane resin mixture as a polymer resin, since it is possible to use relatively low-cost glass fibers in a high content, it is possible to reduce expensive resin costs.

On the other hand, the polyurethane resin mixture, in addition to the main portion A and the curing agent portion B, a trace amount of additives may be further included depending on the characteristics of the pipe.

Thereafter, the liner layer 110 may be formed by defoaming and curing the wound C-glass mat and stitch mat layer (S107).

Referring to FIG. 1, the curing treatment (S107) of the wound C-glass mat and the stitch mat layer may be performed in a curing method known in the art, for example, a curing process at 90° C. for 1 hour in a curing chamber. Further, when winding with a C-glass mat and a stitch mat impregnated with a polyurethane resin mixture on the outer periphery of the mandrel, steam may be injected into the interior space of the mandrel to simultaneously perform winding and curing treatment.

After completion of the curing, a reinforcement operation is performed. Specifically, the continuous fibers impregnated with the polyurethane resin mixture are wound on the outer periphery of the liner layer 110 and cured to form the reinforcing layers 130 (S109, S111).

According to the present invention, the reinforcing layer 130 is formed in the form of a reinforcing rib by filament winding the continuous fibers impregnated in the polyurethane resin mixture on the outer periphery of the liner layer 110.

Here, the reinforcing ribs may have a ring shape made of a plurality of filament layers, and may be formed by varying the number according to the degree of load.

A pipe that is usually buried requires a certain stiffness in order to withstand the earth pressure, and increases the thickness by hoop winding (RTRP) or forms a silica layer on the inside to increase the stiffness (RPMP) to form a reinforcement layer. Did.

In contrast, in the present invention, by forming the reinforcing ribs by the filament winding method, the target stiffness of the pipe can be achieved while reducing the thickness of the reinforcing layer, so that the weight of the pipe can be reduced.

The reinforcement layer 130 of the eco-friendly composite pipe according to the present invention may be formed of a reinforcement rib having a width (Width; W) in the range of 20 to 70 mm and a thickness (T) in the range of 10 to 30 mm. In addition, when forming one or more reinforcing ribs may be formed at intervals (I) of 300 to 1,000 mm range. At this time, the width (W), thickness (T), and spacing (I) ranges of the reinforcing ribs may vary depending on the stiffness or load required for the pipe.

On the other hand, the curing treatment (S111) in the step of forming the reinforcing layer 130, the curing temperature and curing in consideration of the gel time (gel-time) and glass transition temperature (Tg) of the polyurethane resin wound on the reinforcing layer 130 You can set a time. For example, the curing treatment may be performed by a one-step curing at 40°C for 1 hour, followed by a two-step curing at 100°C for 30 to 60 minutes.

In addition, the curing treatment (S111) may be carried out in the same manner as the method of curing treatment (S107) in the step of forming the liner layer 110 described above. That is, when winding continuous fibers impregnated with the polyurethane resin mixture, steam is injected into the interior space of the mandrel to simultaneously perform winding and curing treatment, or after curing, curing treatment is performed at 90°C for 1 hour in the curing chamber. Can be done.

Meanwhile, a process for improving product defects may be additionally performed prior to the curing treatment (S111).

For example, the method of manufacturing the eco-friendly composite pipe of the present invention further comprises the step of winding a polyethylene terephthalate (PET)-based breathable non-woven fabric on the entire outer peripheral surface of the wound continuous fiber before performing the curing treatment (S111). It can contain. By resiliently winding the breathable nonwoven fabric, it is possible to make the layer of the wound continuous fiber uniform. At this time, when the breathable non-woven fabric is wound, the polyurethane resin in the continuous fibers wound to the outer periphery of the non-woven fabric is cut off, and by appropriately removing it, the polyurethane resin reacts with moisture in the air during curing to prevent foaming. can do. In addition, the polyethylene terephthalate (PET)-based breathable non-woven fabric may serve to prevent the phenomenon that the continuous fibers are exposed by weathering. On the other hand, it can also have an aesthetic effect when wrapping a veil printed with color or pattern.

When the reinforcing layer forming process, which is the subsequent reinforcing work described above, is completed, an eco-friendly composite pipe is completed.

[Eco-friendly composite pipe]

2 and 3, the eco-friendly composite pipe 100 according to the present invention includes a liner layer 110; And a reinforcing layer 130 formed to protrude on the outer periphery of the liner layer 110.

The eco-friendly composite pipe 100 of the present invention is provided with a reinforcement layer 130 formed by arranging one or more reinforcement ribs on the outer periphery of the liner layer 110, thereby reducing the thickness of the reinforcement layer 130 to reduce the weight of the pipe. It can further increase the strength of the pipe itself to withstand the load applied from the top, bottom, left and right.

According to a preferred embodiment, the eco-friendly composite pipe according to the present invention can be applied as a pipe for transporting water and sewage. That is, since the eco-friendly composite pipe 100 according to the present invention includes a liner layer 110 with reduced harmfulness and a reinforcing layer 130 having rigidity while having a reduced thickness, it is suitable for water pressure and soil pressure. It is possible to implement a light-weighted pipe for transporting water and sewage while having durability against it.

Hereinafter, the stiffness (SN) and internal pressure (PN) of the eco-friendly composite pipe 100 and the conventional pipe according to the present invention are as follows.

Examples 1-3

The main part A which mixed 70% by weight of polyol having a molecular weight (M/W) of 200 to 350% and 30% by weight of castor oil, and the modified MDI (65% MDI + 35% di, tetra, penta), which is the curing agent part B, 1 Polyurethane resin (PU) was prepared by mixing in a ratio of :1 by weight. Using the prepared polyurethane resin, a pipe having a reinforcement rib formed on a part of the outer periphery of the liner layer was manufactured. At this time, the spacing and width of the reinforcing ribs were adjusted to prepare pipes of Examples 1 to 3, respectively.

Comparative example

Unsaturated polyester resin (UP) was prepared by blending 1% MEKPO (Polynt 3689) with an Ortho-based winding resin. Using the prepared polyester resin, a pipe having a reinforcement layer having an increased thickness on the entire outer periphery of the liner layer was prepared. At this time, a pipe having a thickness of 30 mm and a strength of 5,000 N/m ² was obtained.

Table 1 below shows the comparison of the pipe strength according to the spacing, thickness and width of the reinforcing ribs.

Reinforcement rib pipe interval
(I; mm) width
(W; mm) thickness
(T: mm) thickness
(mm) burglar
(SN; N/m2) Comparative example - 30 5,000 Example 1 2,000 206 33 16.5-20 5,520 Example 2 1,000 206 33 16.5-20 10,800 Example 3 5,000 51.5 33 16.5-20 5,800

* Standard: Diameter (DN) 2,000 mm, Proof pressure (PN) 10 bar

As a result of comparing the strength of the pipes, it was found that the eco-friendly composite pipes according to Examples 1 to 3 had superior strength (SN) to the pipes compared to the conventional pipes according to the comparative example. From this, it was found that by forming the reinforcing rib, the strength SN of the pipe can be improved even if the winding thickness of the reinforcing layer is reduced.

Table 2 below shows the internal pressure (PN) of the pipes in comparison.

Condition Example 1 Comparative example Increased pressure Room temperature Burst at 16 bar Burst at 12 bar 33% or more hot water Burst at 9 bar Burst at 7 bar 28% or more

As a result of comparing the hydraulic pressure of the pipe, the eco-friendly composite pipe according to Example 1 showed that the internal pressure (PN) was improved by 33.33% or more, and 28% or more by hot water, compared to the conventional pipe according to the Comparative Example.

As discussed above, the manufacturing method of the eco-friendly composite pipe according to the present invention is a manufacturing method in which the harmfulness is reduced, the material cost is reduced, and the productivity is improved, and the eco-friendly composite pipe manufactured by this manufacturing method is a product when compared with the conventional pipe. It can be seen that the physical properties are improved with the weight reduction of.

So far, the method for manufacturing an eco-friendly composite pipe according to the present invention and the pipe have been described with reference to the illustrated drawings, but the present invention is not limited to the embodiments and drawings described above. Those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the claims of the present invention. Therefore, the protection scope of the present invention should be interpreted by the claims, which will be described later, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts are included in the scope of the present invention. It should be.

100: eco-friendly composite pipe
110: liner layer
130: reinforcement layer

Claims (9)

(a) releasing the surface of the mandrel;
(b) by the filament winding method, the outer periphery of the mandrel is wound with a C-glass mat (Chemical-Glass Mat) and a stitch mat impregnated with a first polyurethane resin mixture and then defoamed into a net net;
(c) forming a liner layer by defoaming and curing the wound C-glass mat and stitch mat layer;
(d) winding a continuous fiber impregnated with a second polyurethane resin mixture on the outer periphery of the liner layer by a filament winding method; And
(e) curing the wound continuous fibers to form a reinforcing layer,
Each of the first polyurethane resin mixture and the second polyurethane resin mixture includes a main part A containing a polyol and a curing agent part B including an isocyanate-based curing agent in a mixing ratio of 1:1 to 1:1.5,
The isocyanate-based curing agent included in the first polyurethane resin mixture forming the liner layer is an aromatic isocyanate,
The isocyanate-based curing agent contained in the second polyurethane resin mixture forming the reinforcing layer is an aliphatic isocyanate, a method for manufacturing an eco-friendly composite pipe. delete According to claim 1,
The curing treatment in step (c) is carried out at 90° C. for 1 hour, a method for manufacturing an eco-friendly composite pipe. According to claim 1,
The step (b) and step (c) are performed simultaneously while injecting steam into the mandrel interior space, a method for manufacturing an eco-friendly composite pipe. According to claim 1,
Before performing the step (e), further comprising the step of winding a non-woven PET (polyethylene terephthalate)-based non-woven fabric on the entire outer circumferential surface of the continuous fiber, the method of manufacturing an eco-friendly composite pipe. According to claim 1,
The reinforcing layer is a reinforcing rib having at least one ring shape, a method for manufacturing an eco-friendly composite pipe. The method of claim 6,
The reinforcing ribs having a width in the range of 20 to 70 mm and a thickness in the range of 10 to 30 mm, the manufacturing method of the eco-friendly composite pipe. The method of claim 6,
The reinforcing ribs are arranged at intervals in the range of 300 to 1,000 mm, a method of manufacturing an eco-friendly composite pipe. An eco-friendly composite pipe manufactured by a method according to any one of claims 1, 3 to 8,
The composite pipe,
A liner layer cured by impregnating the first polyurethane resin mixture with a wound C-glass mat and a stitch mat; And
It includes a reinforcing layer formed to protrude on the outer periphery of the liner layer, the continuous fiber is cured by impregnating the second polyurethane resin mixture;
Each of the first polyurethane resin mixture and the second polyurethane resin mixture includes a main portion A containing a polyol and a curing agent portion B including an isocyanate-based curing agent in a mixing ratio of 1:1 to 1:1.5,
The isocyanate-based curing agent included in the first polyurepan resin mixture forming the liner layer is an aromatic isocyanate,
The isocyanate-based curing agent contained in the second polyurethane resin mixture forming the reinforcing layer is an aliphatic isocyanate, an eco-friendly composite pipe.

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