JPH0655676A - Manufacture of hose - Google Patents

Abstract

PURPOSE:To achieve continuous production by making it possible to firmly bond a reinforcing layer and an outer layer without using an adhesive. CONSTITUTION:In a method for manufacturing a hose wherein an outer surface layer 5 made of thermoplastic resin is superposed on the outside of a fiber reinforced layer 3 on the inside of which an inner surface layer 2 made of thermoplastic resin is superposed, when the layer 5 is superposed, thermoplastic resin having melt viscosity of 4000 poises or less in a molten state is directly applied to the surface of the layer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hose having thermoplastic resin as an inner and outer surface layer and a reinforcing layer made of fibers such as polyester, nylon, cotton, etc. between the layers, more specifically, the reinforcing layer and the outer surface. The present invention relates to a method for manufacturing a hose having improved adhesion to a layer and enabling continuous production.

[0002]

2. Description of the Related Art Conventionally, when manufacturing this type of hose,
If the outer surface layer of the thermoplastic resin is directly coated on the outer side of the fiber reinforcing layer, sufficient adhesiveness cannot be obtained, so that there is a drawback that the fiber reinforcing layer and the outer surface layer are easily delaminated by repeated bending. Therefore, as a method for adhering the reinforcing layer and the outer surface layer resin, a moisture-curable adhesive or a solvent-based adhesive is interposed between the reinforcing layer and the outer surface layer.

However, when a moisture-curable adhesive is used, it takes a maturing time for a curing reaction before the outer-layer resin is coated after the moisture-curable adhesive is applied and impregnated on the reinforcing layer. Therefore, there is a problem that the hose cannot be continuously manufactured on a series of manufacturing lines, and the productivity cannot be improved. Further, even when a solvent-based adhesive is used, there is a problem that the hose cannot be continuously manufactured because the solvent volatilization time is required, and the volatilization of the solvent causes environmental deterioration.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a method for producing a hose which enables continuous production by enabling strong adhesion between a reinforcing layer and an outer surface layer without using an adhesive. To provide.

[0005]

A method of manufacturing a hose according to the present invention is directed to a hose in which an outer surface layer made of a thermoplastic resin is laminated on the outer side of a fiber reinforced layer having an inner surface layer made of a thermoplastic resin laminated on the inner side thereof. In the manufacturing method, when laminating the outer surface layer of the thermoplastic resin, the surface of the fiber reinforced layer is directly coated with a molten thermoplastic resin having a melt viscosity of 4000 poise or less.

As described above, the melt viscosity on the surface of the reinforcing layer is 400
By directly coating and molding a molten thermoplastic resin having a poise of 0 poise or less as the outer surface layer, the reinforcing layer and the outer surface layer can be firmly bonded without using an adhesive. Can be manufactured continuously. In the present invention, the melt viscosity of the thermoplastic resin forming the outer surface layer is a value measured at the time of coating. Normally, 2.451 is applied to the molten thermoplastic resin when the outer surface layer is coated.
Since a shear stress of about × 10 ⁵ dyn / cm ² is applied, the melt viscosity of the thermoplastic resin under the shear stress of about 2.541 × 10 ⁵ dyn / cm ² is set to 4000 poise or less in the present invention. Define.

The structure of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a molded hose manufactured by the method of the present invention, FIG. 2 is a front view showing a hose manufacturing apparatus according to an embodiment of the present invention, and FIG. 3 is a side view showing the resin extruder thereof. . In the figure, a hose molding 1 is obtained by winding an organic fiber as a reinforcing layer 3 on the outside of an inner surface layer 2 made of a thermoplastic resin in a braided or spiral shape,
The resin is continuously supplied to the resin extruder 10, the cooling device 13, and the take-up machine 14 arranged as a series of production lines. The resin extruder 10 heats and melts the pellet-shaped thermoplastic resin supplied from the hopper 15 while sequentially transferring it to the pressure feeding zone, the melting zone, and the mixing zone in the cylinder section, and melts the molten thermoplastic resin from the head section. The outer surface layer 5 is extruded onto the reinforcing layer 3 to cover and mold the outer surface layer 5. The temperature of each of the cylinder portion and the head portion of the resin extruder 10 can be set, and the melt viscosity of the thermoplastic resin can be controlled by the set temperatures. In the present invention, the resin extruder 10 is controlled so that the melt viscosity of the thermoplastic resin is 4000 poise or less under a shear stress of about 2.451 × 10 ⁵ dyn / cm ² . The cooling device 13 is configured to cool and solidify the outer surface layer 5 formed by coating on the reinforcing layer 3. The hose molding 1 having the outer surface layer 3 provided on the outer side of the reinforcing layer 3 in this manner is taken up by the take-up machine 14 and taken up by a take-up device (not shown).

As described above, by extruding a molten thermoplastic resin having a melt viscosity of 4000 poise or less onto the surface of the reinforcing layer 3 to directly cover and mold the outer surface layer 5, it is possible to form the reinforcing layer 3 without using an adhesive. Since the outer surface layer 5 can be firmly adhered to the outer surface layer 5, the hose molding 1 can be continuously manufactured from the extrusion molding of the inner surface layer 2 to the braiding of the reinforcing layer 3 and the extrusion coating molding of the outer surface layer 5. .

In the present invention, the melt viscosity when extruding the thermoplastic resin of the outer surface layer 5 needs to be 4000 poise or less. This is because when the melt viscosity of the thermoplastic resin at the time of coating exceeds 4000 poise. This is because the adhesive strength between the outer surface layer 5 and the outer surface layer 5 becomes insufficient, so that peeling easily occurs between the layers during pressurization. Further, if the melt viscosity is too low, it becomes difficult to form the outer surface layer 5, so the lower limit is 10
It is preferably 00 poise. As a method for controlling the melt viscosity at 4000 poise or less as described above, in addition to the above temperature control, an appropriate amount of a viscosity reducing agent may be added to the thermoplastic resin.

Further, in the present invention, as the thermoplastic resin constituting the inner surface layer 2 and the outer surface layer 5, a usual hose compound such as nylon, polyester, urethane or the like can be used, and the reinforcing layer 3 As the fiber, fibers such as nylon, polyester and cotton can be used.

[0011]

[Example] As an inner surface layer, a polyester elastomer resin (Toray DuPont Hytrel) having an inner diameter of 9.5 mm,
After extrusion molding to an outer diameter of 11.5 mm, a polyester fiber (Toray Tetron) was braided as a reinforcing layer on the outer side of the inner surface layer by a braiding machine (Kurg Brader). Then, using a resin extruder (ES-40 manufactured by Ikegai Tekko Co., Ltd.), a polyester elastomer resin (Hytrel manufactured by DuPont Toray) was extruded on the reinforcing layer to have an outer diameter of 15.8 mm.

In the above, when the resin for the outer layer is extruded, the temperature of the resin extruder is set as shown in A to F in Table 1 below, and the melt viscosity of the resin for the outer layer is 8000 poise, respectively.
5000poise, 4000poise, 3200poise, 2
A high-pressure hose was manufactured by forming the outer surface layer by coating differently from 800 poise and 1700 poise. The above melt viscosity is obtained by measuring the melt viscosity at the head temperature of the resin extruder in advance using a Koka flow tester of 2.451.
It is a value measured under a shear stress of × 10 ⁵ dyn / cm ² .

[0013] In addition, after manufacturing up to the braiding of the polyester fiber constituting the reinforcing layer in exactly the same manner as above, a moisture-curable adhesive is applied on the reinforcing layer by the conventional method, and after aging for 48 hours, heat with a melt viscosity of 8000 poise is applied. By extruding a plastic resin and coating and molding the outer surface layer, a high-pressure hose having an adhesive layer 4 as shown in FIG. 4 was manufactured.

With respect to these seven kinds of hoses, hose performance tests such as adhesion strength, bending resistance, burst test and fatigue resistance were conducted under the following conditions, and the evaluation results are shown in Table 2. Further, the relationship between the melt viscosity of the outer surface layer resin and the adhesive strength between the reinforcing layer and the outer surface layer is shown in FIG. 5 with the horizontal axis being a logarithmic scale. Adhesive strength It was carried out in accordance with the test conditions of JIS K 6301.

When the bending resistant hose was bent into a U shape with a bending radius of 50 mm, the state of the outer surface layer on the inside of the bending was observed. . Burst test Carried out in accordance with the test conditions of JIS K 6375, and those with no abnormality are indicated by ◯.

Fatigue resistance Tested according to JIS K 6375 test conditions, impact pressure 1
After addition of 50,000 times, no abnormality was indicated by ◯, and peeling of the outer surface layer was indicated by x.

[0017]

As can be seen from Table 2 and FIG. 5, the high pressure hoses (Examples 1 to 4) in which the outer surface layer was directly molded by extruding the resin under the condition that the melt viscosity at the time of coating was 4000 poise or less were Despite the fact that it can be manufactured continuously without using a chemical agent, it shows the same performance as a high-pressure hose (Comparative Example 3) manufactured using a conventional adhesive,
It could be put to practical use.

On the other hand, the melt viscosity at the time of coating is 4000 poise.
The high-pressure hoses (Comparative Examples 1 and 2) in which the resin is extruded under the condition of exceeding (Comparative Examples 1 and 2) are inferior in fatigue resistance and bending resistance to the conventional high-pressure hoses, It was not suitable for practical use.

[0020]

As described above, according to the present invention, there is provided a hose manufacturing method in which an outer surface layer made of a thermoplastic resin is laminated outside a fiber reinforced layer having an inner surface layer made of a thermoplastic resin laminated therein. When laminating the outer surface layer of the thermoplastic resin, a melt viscosity of 400 is applied to the surface of the fiber reinforced layer.
Since the molten thermoplastic resin of 0 poise or less is directly coated and molded, the reinforcing layer and the outer surface layer can be firmly bonded without using an adhesive, so that the hose can be used on a series of production lines. It can be manufactured continuously. By enabling continuous production in this way, work-in-progress products are reduced, storage space is not required, and manufacturing costs can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing a hose molding manufactured by the method of the present invention.

FIG. 2 is a front view showing a hose manufacturing apparatus according to an embodiment of the present invention.

FIG. 3 is a side view showing the resin extruder of FIG.

FIG. 4 is a perspective view showing a hose molding manufactured by a conventional method.

FIG. 5 is a diagram showing a relationship between a melt viscosity of an outer surface layer resin and an adhesive strength between a reinforcing layer and an outer surface layer.

[Explanation of sign]

 1 Hose Molded Product 10 Resin Extruder 2 Inner Surface Layer 13 Cooling Device 3 Reinforcing Layer 14 Pulling Machine 4 Adhesive Layer 15 Hopper 5 Outer Surface Layer

Claims (1)

[Claims] 1. A method for producing a hose, wherein an outer surface layer made of a thermoplastic resin is laminated on the outer side of a fiber reinforced layer having an inner surface layer made of a thermoplastic resin laminated on the inner side thereof. In the method for producing a hose, the surface of the fiber reinforced layer is directly coated with a molten thermoplastic resin having a melt viscosity of 4000 poise or less.