JP2014113763A - Continuous normal pressure vulcanization method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuous normal pressure vulcanization method with which an unvulcanized rubber product is continuously vulcanized with vulcanization speed nearly equal to extrusion speed, while retaining the shape of the product even when the unvulcanized rubber product to be extrusion molded is long and has a large cross-sectional shape.SOLUTION: An unvulcanized rubber product D to be molded with continuous extrusion is sent to, and immersed in, a liquid vulcanization tank 3 in which a liquid heat medium 5, consisting of one liquid or a plurality of liquids with specific gravity less than that of the unvulcanized rubber product, is heated and stored, and vulcanized under normal pressure. The unvulcanized rubber product is continuously vulcanized by maintaining an immersed state in the liquid heat medium 5 without being floated with buoyancy, and uniformly heating the product, while retaining the shape, in accordance with extrusion speed under normal pressure.

Description

  The present invention relates to a continuous normal pressure vulcanization method, and is an unvulcanized rubber product that has been continuously extruded so that it can be vulcanized continuously at normal pressure at almost the same speed as the extrusion speed. It can be vulcanized while maintaining its dimensions.

An unvulcanized rubber product to be extruded needs to be vulcanized to obtain a final rubber product, and various vulcanization methods are employed.
For example, waterproof rubber used for expansion devices for bridges, water and sewerage systems, waterways, water treatment facilities, marine revetments, tunnels, joint grooves, etc. Therefore, it is necessary to vulcanize an unvulcanized rubber product after extrusion molding also for a long rubber product such as a flexible joint used for the purpose.

As a method of vulcanizing such an extruded unvulcanized rubber product, for example, in a fiber reinforced hose, as disclosed in Patent Document 1, a fiber reinforced layer is braided on an inner rubber layer to form a hose body. The hose body is preheated immediately before the outer rubber layer is extruded from the extruder to the outer peripheral surface of the hose body, and volatile components such as oil, air, and moisture contained in the inner rubber layer and fiber reinforcing layer are removed in advance. In addition, continuous vulcanization is performed while avoiding foaming generated between layers by heating during vulcanization.
Further, as a method for vulcanizing a long belt, Patent Document 2 discloses that a rubber belt is pressurized between a pair of upper and lower metal endless bands heated by a heating plate and then vulcanized, and at the same time the pressure is reduced. The endless band made of steel is continuously vulcanized by sequentially repeating feeding a predetermined length.
Furthermore, as a continuous manufacturing method of a conveyor belt, Patent Document 3 discloses that a core material is unwound from an unwinding stand, and cover rubber is extruded on both sides and rolled, and a formed rubber sheet is supplied to a continuous vulcanizer. The vulcanized conveyor belt body is continuously wound up.

JP 07-195382 A JP 2008-049596 A JP 05-301299 A

For example, in the case of a fiber-reinforced hose of Patent Document 1 that has a relatively simple extruded cross-sectional shape and a small diameter, it can be easily continuously vulcanized. If the cross-sectional shape of a flexible joint used for water-stopping of structures such as water and sewage systems, tunnels, and common grooves is large or the shape is complicated, it cannot be easily heated from the outside. There is a problem that the cross-sectional shape cannot be maintained by heating.
Further, in the vulcanization method for a long belt disclosed in Patent Document 2, since vulcanization is performed while pressing between metal endless bands, it is difficult to maintain the cross-sectional shape, and extrusion is performed because it is necessary to repeat pressurization, decompression, and feeding sequentially. There is a problem that it is not possible to continuously perform from molding to vulcanization.
Furthermore, in the continuous manufacturing method of the conveyor belt of Patent Document 3, the vulcanized rubber sheet is continuously wound up, but it cannot be wound up with water-stopping rubber or a flexible joint, as it is. It cannot be applied.
In addition, steam vulcanization is also performed directly on extruded rubber products with a large cross-sectional shape, but depending on the cross-sectional shape, it cannot be heated uniformly, and the dimensions and physical properties are kept at a predetermined level. There is also a problem that it may not be possible.
On the other hand, there is also a vulcanization method that uses a mold to maintain dimensions and physical properties, but it is not practical due to cost to prepare a mold for a long product with a large cross-sectional shape. There is a need to develop a continuous vulcanization process.

  The present invention has been made in view of the above-mentioned problems of the prior art, and is an unvulcanized rubber product that is extruded and has a long and large cross-sectional shape, while maintaining the shape at substantially the same speed as the extrusion speed. An object of the present invention is to provide a continuous atmospheric pressure vulcanization method capable of continuous vulcanization.

  The continuous normal pressure vulcanization method according to claim 1 of the present invention for solving the above-mentioned problems of the prior art is characterized in that the unvulcanized rubber product continuously extruded is vulcanized continuously at normal pressure. The vulcanized rubber product has a specific gravity smaller than that of the vulcanized rubber product, or a liquid heat medium consisting of one or more liquids is heated and stored in the liquid vulcanization tank while sending the unvulcanized rubber product while vulcanizing at normal pressure. It is what.

  According to a second aspect of the present invention, in addition to the constitution according to the first aspect, the liquid heat medium comprising one or more liquids has a boiling point higher than the vulcanization temperature of the unvulcanized rubber product. Is characterized by being high.

  According to a third aspect of the present invention, in addition to the constitution of the first or second aspect, the liquid heat medium is either glycerin or silicone oil. .

  According to a fourth aspect of the present invention, in addition to the structure according to any one of the first to third aspects, the liquid heat medium is glycerin having a high boiling point and a high specific gravity as a main heat medium. It is characterized by comprising glycerin having a specific gravity as an auxiliary heat medium.

  According to a fifth aspect of the present invention, in addition to the constitution according to any one of the first to fourth aspects, the liquid heat medium is composed of glycerin and silicone oil, and the upper portion of the glycerin layer is formed. It is characterized by having two layers covered with a silicone oil layer.

  According to the continuous normal pressure vulcanization method of claim 1 of the present invention, when continuously vulcanizing an unvulcanized rubber product that is continuously extruded at normal pressure, the specific gravity is higher than that of the unvulcanized rubber product. Since the unvulcanized rubber product is sent while being immersed in a liquid vulcanization tank in which a liquid heat medium consisting of a single liquid or a plurality of liquids is heated and stored, and vulcanized at normal pressure, the specific gravity is higher than that of the unvulcanized rubber product. The liquid heat medium can be vulcanized by immersing it in a liquid vulcanization tank that has been heated and stored, and the shape can be maintained by maintaining the immersion state in the liquid heat medium without being lifted by buoyancy. However, it can be heated uniformly and continuously vulcanized. Further, by using a liquid vulcanizing tank, it is possible to continuously vulcanize following the extrusion speed at normal pressure.

  According to the continuous normal pressure vulcanization method according to claim 2 of the present invention, the liquid heat medium composed of the single liquid or the plurality of liquids has a boiling point higher than the vulcanization temperature of the unvulcanized rubber product, Vulcanization of the liquid heat medium and the like can be easily and continuously vulcanized at normal pressure.

  According to the continuous normal pressure vulcanization method according to claim 3 of the present invention, since the liquid heat medium is either glycerin or silicone oil, it is not vulcanized such as a normal water-stopping rubber or a flexible joint. Even a rubber product can be vulcanized by heating to the required vulcanization temperature, and the post-treatment after vulcanization is facilitated without the rubber swelling or reacting with the rubber.

  According to the continuous normal pressure vulcanization method of claim 4 of the present invention, the liquid heat medium is composed of glycerin having a high boiling point and a high specific gravity as a main heat medium, and glycerin having a low specific gravity as an auxiliary heat medium. The main heat medium and auxiliary heat medium can easily adjust the specific gravity of the liquid heat medium, and the unvulcanized rubber product can be immersed in the liquid heat medium without being lifted by buoyancy. The shape and physical properties can be made uniform.

  According to the continuous normal pressure vulcanization method according to claim 5 of the present invention, the liquid heat medium is composed of glycerin and silicone oil, and the upper part of the glycerin layer is covered with the silicone oil layer to form two layers. So, by covering the upper part of the glycerin layer with a silicone oil layer to make two layers, evaporation from the glycerin layer and the diffusion of odors can be suppressed with the silicone oil layer, and it is continuous without deteriorating the surrounding environment Can be vulcanized.

It relates to a continuous vulcanizing apparatus to which an embodiment of the continuous normal pressure vulcanizing method of the present invention is applied, (a) is a schematic cross-sectional view of a liquid vulcanizing tank portion, and (b) is an unvulcanized rubber product. It is a schematic cross-sectional view of the vulcanized state of a certain flexible water-stop joint. It is a schematic sectional drawing concerning the other liquid vulcanization tank part of the continuous vulcanization device with which one embodiment of the continuous normal pressure vulcanization method of this invention is applied. It is a schematic sectional drawing concerning the further another liquid vulcanization tank part of the continuous vulcanization device with which one embodiment of the continuous normal pressure vulcanization method of this invention is applied. It is a cross-sectional view of a still water joint which is an unvulcanized rubber product to which an embodiment of the continuous normal pressure vulcanization method of the present invention is applied, and an explanatory cross-sectional view of a vulcanized state in a liquid vulcanization tank. It is a cross-sectional view of a still water joint which is an unvulcanized rubber product to which an embodiment of the continuous normal pressure vulcanization method of the present invention is applied, and an explanatory cross-sectional view of a vulcanized state in a liquid vulcanization tank. It is a cross-sectional view of an expansion / contraction water stop joint which is an unvulcanized rubber product to which an embodiment of the continuous normal pressure vulcanization method of the present invention is applied, and an explanatory cross-sectional view of a vulcanized state in a liquid vulcanization tank. . FIG. 2 is a cross-sectional view of a flexible water-stop joint that is an unvulcanized rubber product to which an embodiment of the continuous normal pressure vulcanization method of the present invention is applied, and an explanatory cross-sectional view of a vulcanized state in a liquid vulcanization tank. is there. 1 is a cross-sectional view of a substantially U-shaped water-stopping joint that is an unvulcanized rubber product to which an embodiment of the continuous normal pressure vulcanization method of the present invention is applied, and an explanatory cross-section of a vulcanized state in a liquid vulcanizing tank. FIG.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
The continuous normal pressure vulcanization method of the present invention is a continuous vulcanization method for vulcanizing an unvulcanized rubber product that is continuously extruded to obtain a finished rubber product, using a liquid heat medium, It is possible to vulcanize at normal pressure and vulcanize at approximately the same speed as the extrusion molding speed by continuously guiding and immersing unvulcanized rubber products in a liquid vulcanizing tank in which the liquid heat medium is heated and stored. I have to.

  The unvulcanized rubber product to be continuously vulcanized may be of any cross-sectional shape and length as long as it is continuously extruded. Since the cross-sectional shape is complicated and the cross-section has a hollow part, it is possible to continuously vulcanize even a long one with a long length in the extrusion direction. It is said.

  As such an unvulcanized rubber product, for example, as shown in FIGS. 4 to 8, various water-stopping joints can be mentioned, and the water-stopping joint A (see FIG. 4), plate-like on both sides of the cylindrical portion. The water-stopping joint B (see FIG. 5) in which a large-diameter anchor portion is formed at both ends, plate-like portions are formed on both sides of the folded portion at the center, and perpendicular to both ends A telescopic water-stopping joint C (see FIG. 6) formed with a protruding locking part, having one hollow part with an outer shape connecting two trapezoids at the center part, and plate-like parts are formed at both ends, A flexible water-stop joint D (see FIG. 7) in which two ridges are formed in the middle part of the plate-like part, and a V-shaped anchor part that opens laterally on both sides of the U-shaped stretchable part. Various U-shaped water-stopping joints E (see Fig. 8) and various water-stopping joints, rubber water-stopping plates, In addition, a rubber material and a non-water-stopping material can also be mentioned, and any other rubber product having a uniform cross-sectional shape can be continuously vulcanized.

Such an unvulcanized rubber product having a uniform cross-sectional shape is extruded obliquely downward from the die 2 of the head 1 of the extruder, for example, as shown in FIG. In an unvulcanized rubber product that is guided to the inlet 4 and has a hollow portion such as a flexible water-stop joint D, the liquid heat medium 5 is allowed to enter the hollow portion from the opening at the end so that the liquid heat medium 5 can be horizontally added from the inclined inlet portion 4. Vulcanization is started with the liquid heat medium 5 heated to the vulcanization temperature in a state where the unvulcanized rubber product is completely immersed in the liquid heat medium 5 by being guided to the vulcanization part 6 to prevent deformation.
By doing so, it is possible to obtain a vulcanized rubber product in which the unvulcanized rubber product has a predetermined shape and is vulcanized in a horizontal state without deformation to prevent deformation. Then, the vulcanized rubber product is pulled up from the inclined outlet portion 7 of the liquid vulcanizing tank 3, and the liquid heat medium 5 is left in the liquid vulcanizing tank 3 (in the hollow portion of the unvulcanized rubber product). The vulcanized rubber product is taken out, and in the liquid vulcanizing tank 3, the vulcanized rubber product that is continuously extruded is vulcanized.

In such a liquid vulcanizing tank 3, the corner portion from the inclined inlet portion 4 to the horizontal vulcanizing portion 6 is connected by a curve having a sufficiently large radius of curvature so as to prevent deformation.
In this liquid vulcanization tank 3, hot oil circulation parts 8, 8 composed of stainless steel pipes or the like are provided on both sides in the longitudinal direction of the bottom part of the horizontal vulcanization part 6, and the oil is heated and circulated by a heating device (not shown). The liquid heat medium 5 of the horizontal vulcanization unit 6 above the hot oil circulation units 8 and 8 can be heated to a predetermined temperature. The horizontal vulcanization unit 6 of the liquid vulcanization tank 3 has, for example, a hermetic cross section. The outer peripheral portion is hollow and can be insulated and heat-insulated by forming the air heat insulating layer 9, and is installed on a gantry (not shown) via a heat shield plate 10.
The liquid vulcanizing tank 3 is stored and filled with the liquid heat medium 5 up to a height halfway between the inclined portion inlet 4 and the inclined portion outlet 7, and the horizontal vulcanized portion 6 is completely filled with the liquid heat medium 5. .
Further, ducts 11 and 11 for the vapor of the liquid heat medium 5 are provided above the inclined portion inlet 4 and the inclined portion outlet 7 so that the discharge processing can be performed without diffusing the vapor to the surroundings.

The liquid vulcanization tank 3 has a boiling point higher than the vulcanization temperature at which it does not boil even when heated from 135 ° C. to about 170 ° C., which is a temperature necessary for vulcanization of the unvulcanized rubber product, as the liquid heat medium 5. A liquid is used, and is composed of a single liquid, or a liquid heat medium is composed of a mixture of a plurality of liquids. In addition, as the liquid heat medium 5, it is necessary to realize uniform vulcanization by preventing the unvulcanized rubber product from being completely immersed and floating in the liquid heat medium 5. A specific gravity smaller than that of the unvulcanized rubber product is used.
Further, the liquid heat medium 5 is preferably a liquid heat medium 5 that does not react with the unvulcanized rubber product, for example, that does not swell or generate bubbles, and can wash the vulcanized rubber product with water after vulcanization. It is preferable.

Examples of the liquid heat medium 5 satisfying such conditions include glycerin, which has a boiling point of 270 ° C. and a specific gravity of 1.26 (normal temperature), which is close to the specific gravity of rubber and is heated. The specific gravity decreases and becomes close to rubber.
In general, glycerin having a high specific gravity has a high boiling point, but a low specific gravity (1.1 to 1.2) has a slightly low boiling point.
On the other hand, the specific gravity of unvulcanized rubber is generally 1.2 to 1.35 for chloroprene rubber (CR), 1.1 to 1.15 for natural rubber (NR), and 1.1 for ethylene propylene rubber (EPDM). If the glycerin specific gravity is about 1 to 1.2, the unvulcanized rubber product moving in the liquid vulcanizing tank 3 is continuously vulcanized without contacting anything such as surrounding walls. (Refer to FIG. 4 to FIG. 8B). In particular, when the unvulcanized rubber product is thin like the water-stopping joint A, the specific gravity of the liquid heat medium 5 is an important factor in terms of both shape retention and vulcanization progress.

Even in the case of glycerin having a high boiling point, in the vicinity of 150 ° C., the amount of evaporation increases and glycerin is consumed.
For this reason, in the liquid vulcanizing tank 3, the liquid heat medium having a low specific gravity is used for the upper layer and the liquid heat medium having a high specific gravity is used for the lower layer, so that the unvulcanized rubber product is always located in the middle of the liquid heat medium. And can be vulcanized in an immersed state.

  For example, when ethylene propylene rubber (EPDM) is used as an unvulcanized rubber product, high boiling glycerin is used as the main heat medium 5a as the liquid heat medium 5, and glycerin having a slightly lower specific gravity is used as the auxiliary heat medium 5b. The boiling point can be 180 ° C. or higher, the vulcanization temperature can be 145 to 150 ° C., the vulcanization time can be 35 minutes or less, and it can be completely buried and vulcanized.

Further, as a technique for suppressing the evaporation consumption of glycerin, it is effective to fill the glycerin 5a and 5b below the liquid vulcanization tank 3 and float the silicone oil 12 on the uppermost layer.
For example, in the case of this liquid vulcanizing tank 3, the horizontal vulcanization unit 6 is a sealed space surrounded by the periphery, so that the silicone oil 12 is floated on the glycerin surfaces of the inclined inlet part 4 and the inclined outlet part 7. It ’s fine.

  Further, the temperature of the oil circulating by the heating device is adjusted and controlled according to the vulcanization temperature, and the length of the liquid vulcanization tank 3 is set according to the extrusion speed and the vulcanization time. For example, when the extrusion speed is 300 mm / min and vulcanization is performed for 20 minutes, the length of the horizontal vulcanization section 6 of the liquid vulcanization tank 3 may be 6 m, the extrusion speed is 80 mm / min, and 60 In the case of partial vulcanization, the horizontal vulcanization section 6 having a length of 4.8 m may be used.

  In addition to the above-mentioned glycerin and silicone oil, the liquid heat medium includes a molten salt bath (eutectic salt of KNO3 53%, NaNO 240%, NaNO 3% as a heat medium), a molten sulfur bath, hot water, and the like used for molten salt vulcanization. Baths, paraffin baths (eg, C20H42 icosane, C21H44 heicosane etc., CnH2n + 2 n ≧ 20 paraffinic hydrocarbons), low melting point alloys (eg tin-bismuth alloys), vegetable oils (eg rapeseed oil, coconut oil, olive oil, soybean oil, Castor oil, cottonseed oil, linseed oil, etc.), etc., and these can also be used depending on the type of rubber used.

According to such a continuous normal pressure vulcanization method using a liquid heat medium, an unvulcanized rubber product having a uniform cross-sectional shape is continuously extruded and vulcanized continuously at normal pressure without using a mold. can do.
As a result, for example, unvulcanized rubber products having a uniform cross-sectional shape such as a water-stop joint A, a water-stop joint B, a stretch water-stop joint C, a flexible water-stop joint D, and a substantially U-shaped water-stop joint E are continuously formed. As shown in FIG. 1 (b) etc. without pushing out and using a mold, the liquid vulcanization tank 3 does not come into contact with the surrounding walls at all and is continuously floated at normal pressure. Can be vulcanized.
Moreover, even if it is an unvulcanized rubber product having a circular cross section, a polygonal hollow portion, a U-shaped opening, etc., it can be vulcanized while maintaining its shape, and its length is also limited. Even if it is long, it can be continuously vulcanized at normal pressure.
Furthermore, by using a liquid heat medium, the heat transfer efficiency is higher than that of the air vulcanization method, the vulcanization can be performed in a short time, there is no problem such as air oxidation, and the physical properties are not deteriorated.
In addition, when high boiling point high specific gravity glycerin is used as the main heat medium as the liquid heat medium and glycerin having a slightly lower specific gravity is used as the auxiliary heat medium, the density and molecular weight selection range is wide and the specific gravity can be easily adjusted. The rubber product can be vulcanized in a completely immersed state without floating on the liquid heat medium, each part of the product can be vulcanized to uniform physical properties, and glycerin can be removed by washing with water after vulcanization. Can be easily processed after vulcanization.
Furthermore, by allowing the silicone oil to float on the uppermost layer of the liquid heat medium of glycerin, evaporation consumption of glycerin can be suppressed, and the influence on the surrounding environment can be suppressed as much as possible.

Next, in the other liquid vulcanization tank 20 used for this continuous normal pressure vulcanization method, it is made into a box shape with an open top, and as shown in FIG. 2, obliquely downward from the die 2 of the head 1 of the extruder. After being extruded, the unvulcanized rubber product having a hollow portion such as the flexible water-stopping joint D guided to the inlet portion 21 at one end portion of the liquid vulcanizing tank 20 has a liquid heat medium in the hollow portion from the tip opening. 5 is infiltrated, and is smoothly changed from a curved state to a horizontal state via a presser roller 23 provided at the lower end of the entrance-side partition plate 22 to prevent deformation, and is guided to the horizontal vulcanization unit 24 to be unvulcanized rubber. Vulcanization is started with the liquid heat medium 5 heated to the vulcanization temperature with the product completely immersed in the liquid heat medium 5.
By doing so, it is possible to obtain a vulcanized rubber product in which the unvulcanized rubber product has a predetermined shape and is vulcanized in a horizontal state without deformation to prevent deformation. Then, the rubber product after vulcanization is pulled up from the outlet 27 by a take-off device (not shown) via the pressing roller 26 of the outlet-side partition plate 25 at the other end of the liquid vulcanizing tank 20, and the liquid heat medium 5 is removed. In the liquid vulcanization tank 20, the vulcanized rubber product that is continuously extruded is left in the liquid vulcanization tank 20 so as to be left in the liquid vulcanization tank 20 (in the hollow portion of the unvulcanized rubber product). Sulfur is performed.

In the liquid vulcanization tank 20, the glycerin already described as the liquid heat medium 5 is used. For example, a high boiling point glycerin is used as the main heat medium 5a, and a slightly low specific gravity glycerin is used as the auxiliary heat medium 5b. In the horizontal vulcanization portion between the inlet side partition plate 22 and the outlet side partition plate 25, the silicone oil 12 is floated on the uppermost layer of the liquid heat medium 5 to suppress the consumption due to evaporation of the liquid heat medium 5 and To minimize the impact on the environment.
Although heating of the liquid heat medium 5 is not shown, any method may be used, such as a method of heating and circulating hot oil in the stainless pipe already described.

  According to such a liquid vulcanization tank 20, the liquid vulcanization tank 20 can be simplified, and the liquid vulcanization tank 20 can be vulcanized by applying the above-described continuous normal pressure vulcanization method. In the state where the shape is maintained by being immersed in a liquid heat medium, the same effect can be obtained, for example, vulcanization can be performed at substantially the same speed as the extrusion speed.

  Further, as shown in FIG. 3, the liquid vulcanizing tank 30 to which the continuous normal pressure vulcanizing method is applied is an unvulcanized rubber product that is continuously extruded downward from the die 2 of the head 1 of the extruder by vertical extrusion. It is suitable as a liquid vulcanizing tank, and is continuous and keeps its shape even if it is a multi-walled multi-cell structure having a thin honeycomb shape and a large number of hollow parts, such as a water-stopping joint A. It can be vulcanized.

In this liquid vulcanizing tank 30, the inlet side vulcanizing tank 31 of the unvulcanized rubber product is deepened, and compared with the vulcanization temperature simultaneously with the extrusion from the front end opening of the unvulcanized rubber product extruded vertically downward. The liquid heat medium 5 such as low-temperature glycerin is infiltrated, smoothly curved in a U shape via the two under rollers 32, 32, and further in a horizontal state via the guide roller 33, so that another liquid vulcanizing tank 3 and 20 is guided to a horizontal vulcanization section 34 having a depth similar to that of the horizontal vulcanization section 34, and is pressed by a plurality of pressing rollers 35 provided at regular intervals above the horizontal vulcanization section 34. As in the case of, vulcanization is started with the liquid heat medium 5 heated to the vulcanization temperature in a state where the unvulcanized rubber product is completely immersed in the liquid heat medium 5.
By doing so, it is possible to obtain a vulcanized rubber product in which the unvulcanized rubber product has a predetermined shape and is vulcanized in a horizontal state without deformation to prevent deformation. The rubber product after vulcanization is pulled up by a take-off device (not shown) via a guide roller 36 on the outlet side of the other end of the liquid vulcanization tank 30, and the liquid heat medium 5 is left in the liquid vulcanization tank 30. Thus, the vulcanized rubber product is taken out, and in the liquid vulcanization tank 30, the vulcanized rubber product that is continuously extruded is vulcanized.

In this liquid vulcanization tank 30, the glycerin already described as the liquid heat medium 5 is used, for example, a high boiling point glycerin is used as the main heat medium 5a, and a slightly low specific gravity glycerin is used as the auxiliary heat medium 5b. In the horizontal vulcanization unit 34, the silicone oil 12 is floated on the uppermost layer of the liquid heat medium 5, so that consumption due to evaporation of the liquid heat medium 5 is suppressed and influence on the surrounding environment is suppressed as much as possible.
The liquid heat medium 5 is heated by a method of heating and circulating hot oil in the stainless steel pipe, or may be heated by other methods.
The inlet side guide roller 33, the pressing roller 35, and the outlet side guide roller 36 may be made of, for example, MC nylon that does not require a bearing, and may be provided with a drive mechanism as necessary.

  According to such a liquid vulcanizing tank 30, it is possible to maintain a shape even with respect to a vertically extruded unvulcanized rubber product and to make it horizontal, and this liquid vulcanizing tank 30 has already been described. It can be vulcanized by applying the normal pressure vulcanization method, and has the same effect as being able to vulcanize at substantially the same speed as the extrusion speed while maintaining the shape by dipping in a liquid heat medium. .

In the liquid vulcanization tanks 3, 20, and 30, when the uncured rubber product has its front end opened into the liquid heat medium 5 and the vulcanized rubber product after vulcanization is pulled up, the liquid heat Although continuous vulcanization was carried out so as to leave the medium, the vulcanized rubber product was cut and cut at regular intervals, and the tip opening was newly opened. You may make it penetrate | invade in a liquid heat medium, and you may make it provide the spider mechanism which inject | pours a liquid heat medium into a hollow part from a male rod of the die | dye of an extruder.
Furthermore, at the start of extrusion of unvulcanized rubber products, a dummy guide rope is used so that continuous vulcanization can be achieved while minimizing the occurrence of initial reservoir and initial waste.
Further, the liquid vulcanization tank can be constituted by, for example, a stainless steel plate welded structure, which is externally silicon-lined and then kept warm with glass wool.

  In the above embodiment, the continuous normal pressure vulcanization of the flexible waterproof joint D is described as an example of the rubber product. However, in addition to other waterproof joints, a rubber waterproof plate, a sealing material, Application to unintended purposes is also possible.

A water stop joint B water stop joint C expansion water stop joint D flexible water stop joint E substantially U-shaped water stop joint 1 head 2 dice 3 liquid vulcanizing tank 4 inclined inlet 5 liquid heat medium 5a main heat medium 5b Auxiliary heat medium 6 Horizontal vulcanization section 7 Inclined outlet section 8 Hot oil circulation section 9 Air insulation layer 10 Heat insulation plate 11 Duct 12 Silicone oil 20 Liquid vulcanization tank 21 Inlet section 22 Inlet side partition plate 23 Presser roller 24 Horizontal vulcanization Portion 25 Exit side partition plate 26 Press roller 27 Exit portion 30 Liquid vulcanization tank 31 Entrance portion 32 Under roller 33 Guide roller 34 Horizontal vulcanization portion 35 Press roller 36 Guide roller

Claims (5)

When continuously vulcanizing unvulcanized rubber products that are continuously extruded at normal pressure,
The unvulcanized rubber product is vulcanized at normal pressure by immersing the unvulcanized rubber product in a liquid vulcanization tank in which a liquid heat medium composed of a single liquid or a plurality of liquids having a specific gravity smaller than that of the unvulcanized rubber product is heated and stored. A continuous atmospheric pressure vulcanization method. 2. The continuous normal pressure vulcanization method according to claim 1, wherein the liquid heat medium composed of one or a plurality of liquids has a boiling point higher than a vulcanization temperature of the unvulcanized rubber product. 3. The continuous normal pressure vulcanization method according to claim 1, wherein the liquid heat medium is glycerin or silicone oil. The continuous atmospheric vulcanization according to any one of claims 1 to 3, wherein the liquid heat medium is composed of glycerin having a high boiling point and a high specific gravity as a main heat medium and glycerin having a low specific gravity as an auxiliary heat medium. Method. The continuous liquid according to any one of claims 1 to 4, wherein the liquid heat medium is composed of glycerin and silicone oil, and the upper part of the glycerin layer is covered with a silicone oil layer to form two layers. Pressure vulcanization method.

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