JP3904699B2 - Twin hose and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a hose used for transporting hot water at 120 ° C. or less for recirculation bath circulation, floor heating, injection temperature control, etc., and mainly has two twins for forward and return use. This relates to the hose used in the above.
[0002]
[Prior art]
Conventionally, as this type of hose, an inner layer rubber tube made of EPDM, a reinforcing layer formed by winding a plurality of reinforcing yarns made of vinylon or aromatic polyamide fiber around its outer peripheral surface, and EPDM on its outer peripheral surface A hose formed by forming an outer-layer rubber made of is known.
[0003]
In order to make these hoses into a twin structure, two hose formed up to the reinforcing layer are prepared, and when the outer layer rubber is extruded, it is extruded into glasses to form a twin and then vulcanized. And a method of binding a single vulcanized rubber hose with a string and a binding jig.
[0004]
In the former method in which the outer layer rubber is twinned when the outer layer rubber is extruded, the processing speed can be increased if there are variations in the dimensions of the two hoses on which the reinforcing layer has been formed, bending, and the knitting angle of the reinforcing yarn. Therefore, processing is difficult and the cost is high. On the other hand, in the method of bundling two vulcanized single hoses, if the bundling pitch is not reduced, the hose is separated at the unbundled portion, which is inconvenient to handle. There was a problem that processing costs were required.
[0005]
On the other hand, in order to make a hose having a twin structure by heat fusion, PVC is used for the inner layer and the outer layer, and a hose in which a hard steel wire is wound in a spiral shape or a reinforcing yarn is wound around the reinforcing layer. It has been known. In this PVC hose, PVC is also used for the inner layer. When warm water circulates in the inner layer PVC pipe, the plasticizer blended in the inner layer PVC is extracted by the hot water, and the hose is hardened and the hose is hardened. There was a drawback that leakage was likely to occur at the folds and pipe joints.
[0006]
[Problems to be solved by the invention]
The present invention improves the drawbacks of the prior art by making a composite hose using a thermoplastic resin as the outermost layer of the hose.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve the above problems, and the first of the invention relates to a twin hose for hot water resistance , and from EPDM in which the blending amount of carbon black is 5 parts or less. The formed inner rubber tube, the reinforcing layer in which the reinforcing thread is wound around the outer peripheral surface of the inner rubber tube, the intermediate rubber layer disposed on the outer peripheral surface of the reinforcing layer, and the outer peripheral surface of the intermediate rubber layer are thermoplastic. Two composite hoses provided with a resin layer are continuously fused in the thermoplastic resin layer .
[0008]
The second aspect of the invention relates to a method for manufacturing a twin hose, and is a first step in which an EPDM having a carbon black content of 5 parts or less is extruded onto a rubber or resin mandle to constitute an inner rubber tube , A second step of forming a reinforcing layer by winding a reinforcing thread around the outer peripheral surface of the inner layer rubber tube, a third step of forming an intermediate rubber layer by extruding rubber on the outer peripheral surface of the reinforcing layer, and heating the above the layers of rubber vulcanized, then extruded and fourth step overtake the mandrel, and a fifth step of applying an adhesive to the surface of the intermediate rubber layer, the surface of the intermediate rubber layer coated with adhesive thermoplastic resin A sixth step of forming a thermoplastic resin layer, and a seventh step of heating and softening the thermoplastic resin layer of the composite hose obtained in the sixth step to continuously heat-bond the composite hoses together. It is the method which has.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The first composite hose of the present invention includes an inner layer rubber tube, a reinforcing layer in which a reinforcing thread is wound around the outer peripheral surface of the inner layer rubber tube, an intermediate rubber layer disposed on the outer peripheral surface of the reinforcing layer, and A composite hose for hot water resistance that has a thermoplastic resin on the outer peripheral surface of this intermediate rubber layer. The inner rubber tube uses EPDM to withstand the circulation of hot water, withstands chlorine water and bathing agents, and is extracted. It is preferable to use a compound with a small amount of water and low moisture permeation. In particular, in order to prevent black contamination that carbon is extracted on the rubber surface, it is important to keep the amount of carbon blended to 5 parts or less, and the hardness of the rubber is preferably 60 to 80 °.
[0010]
As the reinforcing yarn used for the reinforcing layer, it is preferable to use vinylon when hot water is less than 100 ° C. at the use temperature of the hose, and when it exceeds 100 ° C., aromatic polyamide fiber or mild steel wire is used. In particular, vinylon is inexpensive and is desired to be used at all operating temperatures. However, since hot water may cause hydrolysis, the operating temperature is less than 100 ° C.
[0011]
The intermediate rubber layer formed on the reinforcing layer is mainly used for the purpose of ensuring adhesion with the outer resin layer, and an adhesive is applied directly or after buffing to the outer surface of the intermediate rubber layer. A resin layer is extruded and coated on the outer peripheral surface.
[0012]
The outer resin layer is made of a thermoplastic resin to facilitate heat-sealing, and olefinic TPE, PVC, polyurethane resin, styrenic resin, etc. are mainly used when hot water is less than 100 ° C. Olefin-based TPE, silicone resin, polyamide resin and the like can be used.
[0013]
The hardness of these resins is preferably 50 to 70 ° in order to ensure flexibility as a composite hose. Further, by making the outer layer a resin layer, the hose can be easily colored, and the forward and return hose can be easily color-coded.
[0014]
In the second hose manufacturing method of the present invention, an inner layer rubber tube is extruded on a rubber or resin mandle to a specified thickness. A reinforcing thread is wound around the outer peripheral surface to form a reinforcing layer, and the wound structure may be spiral or preed. An intermediate rubber layer is extruded to a predetermined thickness on the outer peripheral surface of the reinforcing layer. Thereafter, vulcanization is carried out at a specified temperature for a certain time, and after vulcanization, the mandle is extracted to form a rubber hose. By making these continuous processing, processing costs can be reduced and quality can be stabilized. Next, the surface of the intermediate rubber layer of the vulcanized rubber hose is buffed, a prescribed adhesive is applied, a thermoplastic resin is extruded to a prescribed thickness, and a composite hose is formed. Buffing is not essential, but it is desirable to perform this step in order to ensure adhesion. This composite hose is cut to a specified length, and two hose units are heat-sealed to form a twin structure. The method of heat fusion for making this twin structure is as follows. The hot air set according to the melting point of the resin used for the outer layer is discharged from the tip of the nozzle, the outer layer resin is softened and the hoses are pressure-bonded. Can be realized.
[0015]
The size of the composite hose of the present invention is not particularly limited. For example, the inner rubber tube 1 has a diameter of 5 to 50 mm, a thickness of 1 to 4 mm, and the intermediate rubber layer 3 is mainly made of NBR. The thickness is 0.5-2 mm, and the thickness of the outer resin layer is about 0.5-2 mm.
[0016]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
FIG. 1 is a side view of a composite hose according to the first aspect of the present invention, and FIG. 2 is a cross-sectional view of this composite hose. In the figure, 1 is an inner rubber tube made of EPDM, 2 is a reinforcing layer made of an aromatic polyamide fiber, and the winding angle is preferably 54 degrees 44 minutes (static angle). 3 is an intermediate rubber layer mainly composed of NBR, and 4 is an outer layer made of PVC. Of course, this composite hose can be used as a single hose. In each layer in this example, the diameter of the inner rubber tube 1 was 14 mm, the thickness was 1.5 mm, the thickness of the intermediate rubber layer 3 was 1 mm, and the thickness of the outer resin layer was 0.9 mm.
[0017]
Next, using the obtained composite hose, in the seventh step of the second invention, it is heated with a hot air nozzle (hot air temperature 200 to 500 ° C.) to soften the fourth PVC layer. -The twin hose shown in Fig. 2 is formed by pressure contact with a roller or the like. The hot air temperature is appropriately selected depending on the type of the outer surface resin layer and the processing speed of the hose. The processing speed is usually in the range of 2 to 15 m / min.
[0018]
【The invention's effect】
Speaking of the second invention of the present invention, a twin hose can be obtained simply by heating and joining the outer layers of the composite hose. By continuous processing, the processing cost is reduced and the quality is stabilized. Sex is measured.
[Brief description of the drawings]
FIG. 1 is a side view of a composite hose according to a first invention.
FIG. 2 is a sectional view of a twin hose in the second invention.
[Explanation of symbols]
1 ... Inner rubber tube,
2 ... Reinforcing layer,
3. Intermediate rubber layer,
4 ... The resin outer layer.

Claims (6)

Inner layer rubber tube formed of EPDM having a carbon black content of 5 parts or less, a reinforcing layer in which a reinforcing thread is wound around the outer peripheral surface of the inner layer rubber tube, and an intermediate rubber disposed on the outer peripheral surface of the reinforcing layer A twin hose for hot water resistance, characterized in that two composite hoses having a thermoplastic resin layer on the outer peripheral surface of the intermediate rubber layer and the intermediate rubber layer are fused continuously in the thermoplastic resin layer . The twin hose for hot water resistance according to claim 1, wherein the reinforcing yarn is vinylon. The twin hose for hot water resistance according to claim 1, wherein the reinforcing yarn is an aromatic polyamide fiber. A first step of forming an inner rubber tube by extruding EPDM having a carbon black content of 5 parts or less onto a rubber or resin mandle;
A second step of forming a reinforcing layer by winding a reinforcing thread around the outer peripheral surface of the inner layer rubber tube;
A third step of forming an intermediate rubber layer by extruding rubber to the outer peripheral surface of the reinforcing layer;
A fourth step of heating to vulcanize the rubber of each layer and then pulling out the mandle;
A fifth step of applying an adhesive to the surface of the intermediate rubber layer;
A sixth step of forming a thermoplastic resin layer by extruding a thermoplastic resin on the surface of the intermediate rubber layer coated with the adhesive;
A seventh step of heating and softening the thermoplastic resin layer of the composite hose obtained in the sixth step to continuously heat-bond the composite hoses together;
A method for producing a twin hose, comprising: The method for producing a twin hose according to claim 4, wherein the reinforcing yarn is vinylon. The method for producing a twin hose according to claim 4, wherein the reinforcing yarn is an aromatic polyamide fiber.

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