JPH02258321A - Manufacture of rubber hose having synthetic resin thin wall inner tube and its device - Google Patents

Abstract

PURPOSE:To bond well an inner tube and an intermediate rubber layer by applying and cooling a bonding agent on the outer periphery of a synthetic resin thin wall inner tube extruded on the outer periphery of a mandrel and then evaporating and removing a solvent of the bonding agent in a vacuum chamber, extruding unvulcanized rubber to the outer periphery of the inner tube by means of an extruder and forming the intermediate rubber layer. CONSTITUTION:A mandrel 1 with a synthetic resin thin wall inner tube 3 formed on its outer periphery is moved to a vacuum chamber 5, passed through in a bonding agent adjusted at the temperature of 10 deg.C at an applying section 6 and the bonding agent is applied to the outer periphery of an inner tube 3 and simultaneously the mandrel is cooled down by the bonding agent. The solvent in the bonding agent is evaporated and removed while the bonding agent moves through the vacuum chamber 5 and inserted into a rubber extruder 7 to form an intermediate rubber layer 8 such as NBR on the outer periphery of the inner tube 3. Further, a reinforced layer on an outer surface rubber layer composed of polyester or the like is formed on the outer periphery of the intermediate rubber layer and vulcanized, and the mandrel 1 is pulled out to manufacture a rubber hose. Thus, the inner tube 3 and the intermediate rubber layer 8 are bonded well and stably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for manufacturing a rubber hose having a thin-walled synthetic resin inner tube.

[Conventional technology]

A synthetic resin thin-walled inner tube is extruded into a tube shape onto the outer periphery of a flexible mandrel made of rubber or the like using a synthetic resin extruder, and an unvulcanized intermediate rubber layer is placed around the outer periphery of this synthetic resin thin-walled inner tube using a rubber extruder. A method for producing a rubber hose, in which a reinforcing layer and an unvulcanized outer rubber layer are applied to the outer periphery of the intermediate rubber layer, the unvulcanized rubber hose is vulcanized, and a mandrel is pulled out from the vulcanized hose. is JP-A-61-2
It is publicly known from 97118 and the like.

In manufacturing this rubber hose, the intermediate rubber layer cannot be extruded around the outer periphery of the mandrel unless the thin-walled synthetic resin inner tube extruded into a tube shape by a synthetic resin extruder is sufficiently cooled by water cooling. The reason for this is that when the intermediate rubber layer is extruded onto the unsolidified thin synthetic resin inner tube, the thickness of the thin synthetic resin inner tube becomes uneven. Cooling requires a cooling device and a drying device to dry the water used for cooling, which not only takes up space, but also when extruding the intermediate rubber layer to the outer periphery of the thin synthetic resin inner tube, the thin synthetic resin inner tube and the intermediate rubber There is a problem that air and moisture in the air enter between the layers and reduce the adhesive strength between the layers. Further, during drying, dirt in the air may cause adhesion failure.

[Problems to be Solved by the Invention] The present invention provides a manufacturing method that does not require equipment such as a water cooling device or a drying device, and can produce a rubber hose in which a thin synthetic resin inner tube and an intermediate rubber layer are well bonded. and to provide a device.

[Means to solve the problem]

In the present invention, a passage of a mandrel between a synthetic resin extruder and a rubber extruder is surrounded by a vacuum chamber, and a tube-shaped material is extruded around the outer periphery of the mandrel by an application section located near the synthetic resin extruder in the vacuum chamber. At the same time, the adhesive is applied to the outer periphery of the thin-walled synthetic resin inner tube, the thin-walled synthetic resin inner tube is cooled by the adhesive, the solvent mixed with the adhesive is removed by evaporation while passing through a vacuum chamber, and the rubber is unvulcanized using a rubber extruder. A synthetic resin extruder that extrudes rubber onto the outer periphery of a thin synthetic resin inner tube to form an intermediate rubber layer, a synthetic resin extruder that extrudes the thin synthetic resin inner tube into a tube shape around the outer periphery of a mandrel, and a thin synthetic resin inner tube on the outer periphery of the mandrel. a rubber extruder for extruding unvulcanized rubber to the outer periphery; a vacuum chamber surrounding a passage of a mandrel between the synthetic resin extruder and the rubber extruder; and a vacuum chamber disposed near the synthetic resin extruder in the vacuum chamber. A thin-walled synthetic resin characterized by comprising an adhesive application section, an adhesive tank, and an adhesive temperature control device disposed in the middle of an adhesive supply pipeline from the adhesive tank to the application section. A device for manufacturing a rubber hose having an inner tube is used as a means to solve the problem.

[Effect]

In a rubber hose with a thin-walled synthetic resin inner tube, the thickness of the innermost thin-walled synthetic resin tube is at most Q, 5 m.
s, usually 0.1 to 0.311 III theal.

In the present invention, we have focused on the thin thickness of this thin synthetic resin inner tube, and have found that cooling can be performed using an adhesive applied to bond the thin synthetic resin inner tube to the intermediate rubber layer on the outside. This is what I found.

Since the adhesive used for coating in the coating section 6 is cooled,
There is also less evaporation of solvent. Further, the adhesive applied to the outer surface of the high-temperature thin synthetic resin inner tube extruded around the outer periphery of the mandrel is warmed by the thin synthetic resin inner tube, promoting evaporation of the solvent mixed in the adhesive. Therefore, the solvent can be efficiently removed by subsequently moving the thin-walled synthetic resin inner tube coated with the adhesive into the vacuum chamber, and the solvent can also be efficiently recovered by exhausting the vacuum chamber.

This method can be carried out using equipment equipped with a temperature control device that cools the adhesive supplied from the adhesive tank to the application section to a low temperature.

If the mandrel is also supplied to the synthetic resin extruder in a cooled state during periods of high temperature such as summer, the synthetic resin extruded around the mandrel can be quickly cooled from the inside.

(Example) A specific example of the method of the present invention will be described with respect to an embodiment of the apparatus of the present invention shown in the drawings.

The synthetic resin extruder 2 and the rubber extruder 7 have well-known crossheads. A vacuum chamber 5 is provided so as to surround the outlet of the synthetic resin extruder 2 and the inlet of the rubber extruder 7 and cover the passage of the mandrel 1 between the two. A coating section 6 is provided in a portion of the vacuum chamber 5 near the synthetic resin extruder 2. The application section 6 is provided with a die-shaped inlet and an outlet through which the mandrel 1 having the synthetic resin thin-walled inner tube 3 formed on its outer periphery can just pass through. An adhesive tank 9 is provided outside the vacuum chamber 5, and the adhesive in the adhesive tank 9 is supplied to the application section 6 by a pump 10 and applied to the outer periphery of the thin synthetic resin inner tube 3 on the outer periphery of the mandrel 1. A temperature control device 11 is provided in the middle of the adhesive transfer pipe from the pump 10 to the application section 6.
0, the adhesive sent to the application section 6 is cooled. An exhaust pipe 4 is provided in the vacuum chamber 5 so as to communicate with a vacuum device (not shown). The solvent gas taken out from the exhaust pipe 4 is recovered by a recovery device and returned to the adhesive tank 9 for reuse.

A mandrel 1 with a diameter of 15 mm is continuously inserted into a synthetic resin extruder 2, and the synthetic resin extruder 2
Supplying nylon 11 melted to 20σ, mandrel 1
A thin synthetic resin inner tube 3 having a thickness of 0.2 m was formed around the outer periphery of the tube. Continue to apply this mandrel 1 to a vacuum degree of 500 to 700.
The tube is moved to a vacuum chamber 5 whose pressure is reduced to about mHg, passed through the adhesive stored in the coating section 6 and whose temperature is controlled to IOC'', and at the same time, the adhesive is coated on the outer periphery of the thin synthetic resin inner tube 3. The thin synthetic resin inner tube 3 was cooled from the outer periphery with adhesive.The adhesive applied around the thin synthetic resin inner tube 3 was warmed by the heat held by the thin synthetic resin inner tube 3 and moved through the vacuum chamber 5. During this process, the solvent was evaporated and the tube was inserted into a rubber extruder 7, where an intermediate rubber layer 8 of NBR or the like having a thickness of 2 mm was formed on the outer periphery of the thin synthetic resin inner tube 3.Intermediate rubber layer After forming the mandrel 1, a reinforcing layer such as polyester and an outer rubber layer are further formed on the outer periphery and vulcanized.
I pulled it out and got a rubber hose. The adhesive overflowing in the application section 6 is returned to the adhesive tank 9, and the humidity control bag rR11
The adhesive was supplied to the coating section 6 through the adhesive tank 9, where it was maintained at a predetermined viscosity by adding a solvent.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a rubber hose in which the thin-walled synthetic resin inner tube and the intermediate rubber layer are well bonded to each other, and an extremely stable adhesive force can be guaranteed without requiring equipment such as a water cooling device or a drying device. .

[Brief explanation of drawings]

The drawing is a partially sectional side view of an embodiment of an apparatus used for carrying out the method of the present invention.・・Mandrel 2・・Synthetic resin extruder・・Synthetic resin thin wall inner tube・・Exhaust pipe 5・・Vacuum chamber・・Applying section 7・・Rubber extruder・・Intermediate rubber layer 9・・Adhesive tank・・Pump 11...Temperature control device

Claims (2)

[Claims] (1) A rubber hose in which a synthetic resin thin-walled inner tube is extruded into a tube shape onto the outer periphery of a mandrel using a synthetic resin extruder, and an unvulcanized intermediate rubber layer is extruded and molded onto the outer periphery of this synthetic resin thin-walled inner tube using a rubber extruder. In this manufacturing method, the passage of a mandrel between a synthetic resin extruder and a rubber extruder is surrounded by a vacuum chamber, and a thin-walled synthetic resin is extruded into a tube shape in a coating section located near the synthetic resin extruder in the vacuum chamber. At the same time as adhesive is applied to the outer circumference of the inner tube, the thin synthetic resin inner tube is cooled by the adhesive, and the solvent mixed with the adhesive is removed by evaporation while passing through a vacuum chamber, and unvulcanized rubber is synthesized using a rubber extruder. A method for manufacturing a rubber hose having a thin-walled synthetic resin inner tube, comprising forming an extruded intermediate rubber layer on the outer periphery of the thin-walled inner tube. (2) A synthetic resin extruder that extrudes a thin synthetic resin inner tube into a tube shape around the outer periphery of a mandrel, a rubber extruder that extrudes unvulcanized rubber onto the outer periphery of the thin synthetic resin inner tube around the outer periphery of the mandrel, and the synthetic resin extruder a vacuum chamber surrounding the mandrel passage between the rubber extruder and the rubber extruder, an adhesive application section of the vacuum chamber disposed near the synthetic resin extruder, an adhesive tank, and a 1. An apparatus for manufacturing a rubber hose having a thin-walled synthetic resin inner tube, comprising an adhesive temperature control device disposed in the middle of an adhesive supply conduit to an application section.