JPH0243010A - Continuous vulcanization of rubber hose - Google Patents

Abstract

PURPOSE:To vulcanize continuously and freely a long and short hoses of arbitrary lengths in the conveyor system without changing an operation process, by a method wherein a steam pipe supplying steam up to a fixed point within a hose is set up and the steam having fixed pressure and temperature is injected inside the hose through an injection part in close vicinity of the tip of the steam pipe. CONSTITUTION:A former F obtained by assembling a large number of sending- out bars 8 tilted for screw use into an assembly frame 9 whose circumference is turned is driven by a driving body 10 and a vulcanizing steam pipe 7 is supported in a state of heat insulation at the center of the assembly frame 9. A strip of a necessary width of an inner layer member 1 is wound round the former F with appropriate tightening force so that a vulcanized rubber side becomes the inside, a steel wire reinforcing layer 6 is set up by adjusting the same, round which an outer layer member 5 is wound. A steam action range S of a molded hose is heated continuously with steam injection through an injection part J and continuous vulcanization is performed at, for example, a pressure fixed part of 3,000mm.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is a long, light fJrN rubber hose that can be used in a wide range of industries, and which also has the characteristics of a rubber hose with high strength and high pressure resistance. This invention relates to a continuous vulcanization method for obtaining rubber hoses at low cost.

[Conventional technology]

(b) The conventional mandrel forming vulcanization method is a lamination method using a mandrel, and requires equipment that is at least twice the length of the mandrel. A long vulcanizing can longer than the length of gold is required. Therefore, the manufacturing length is naturally limited, and is usually 10 m to 207 m.
R is the limit value.

Furthermore, direct steam vulcanization has low thermal efficiency and requires time to raise the temperature of the can when the can itself is large. In addition, since the structure is made by laminating various flexible raw materials and contains air bubbles, it is usually tightened with a tightening cloth after deaeration and vulcanization, and after vulcanization, the tightening cloth is loosened and a rubber hose is It is a method of mining and consists of many intermittent steps.

This method is suitable for thick products that require long-term vulcanization, high pressure resistant hoses that contain spiral reinforcing wires, or use multilayer reinforcing fabrics.

(b) The flexible mandrel molding method uses rubber or plastic material as the core material instead of a mandrel, and since the core material itself is flexible, it can be molded to a certain finite length and vulcanized. However, there is a limit to the length. In addition, due to the nature of the heartwood,
Not suitable for large diameter hoses. Note that the steps following the use of the tightening cloth are the same as the method (a).

(c) Mold method such as leaded vulcanization.

The leaded method or continuous mold method (multiple delivery mold vulcanization method) is a method of vulcanizing without using a tightening cloth, but it is a batch vulcanization of a fixed length, and the molding process is quasi-continuous. However, it requires large and expensive equipment.

(d) Continuous hot air vulcanization method.

In this method, a continuously formed unvulcanized laminated hose without a core is brought into contact with hot air from its inner and outer surfaces, or only from the outer surface, to perform heat vulcanization. Direct contact causes the surface to become sticky. Furthermore, since hot air has a small heat capacity, it requires several times the heat vulcanization time compared to direct steam vulcanization, and even though it is a continuous production method, the production speed is extremely slow. Furthermore, since it is a continuous manufacturing method, it is not possible to apply pressure, and therefore the air bubbles present inside cannot be degassed.

Alternatively, since the tightening force is not 1q, it is not suitable for heat vulcanization of composite laminates that require homogeneous and strong adhesive strength.

(E) Continuous hot water or hot liquid vulcanization or powder vulcanization method.

These methods increase the heat capacity of the heat medium and are intended to shorten the vulcanization time, but pressure molding is still not possible. In addition, hot water and hot liquid have the disadvantage that there is a limit to their high temperatures and that the liquid and powder adhere to the outer surface of the hose.

The above is an overview of the technical content of conventional hose manufacturing methods.

[Problem to be solved by the invention]

The problems of the above-mentioned prior art are enumerated as follows.

The continuous vulcanization method for rubber hoses of this invention solves the problems of the conventional method shown in the table above, provides high-speed continuity, can be manufactured with relatively inexpensive equipment, and maintains adhesion and dimensional stability of each part. The aim is to provide a manufacturing method with good properties and no contamination.

(Means for Solving the Problems) First, as a continuous forming method for a hose, for example, an inclined thread for continuously feeding out a hose-like form while connecting and laminating each constituent member forming a hose. A former is used in which a large number of delivery bars are assembled in an inclined manner in an assembly frame. That is, as shown in the schematic explanatory diagram of the continuous vulcanization method for rubber hoses in FIG. They are arranged and fixed on the fixed frame 9 while being inclined by a certain amount of deviation toward the center line of the molded product, and the diameter of the arrangement decreases to a predetermined diameter in the flow direction of the molded product. The former F consisting of the plurality of delivery bars 8 is rotated at the same circumferential speed by, for example, a driving body 10, etc.
They are driven to rotate simultaneously. Details of the figure will be described later.

Next, forming the hose will be explained.

The laminated materials are sequentially supplied from the larger diameter side of the former F at an angle of inclination, and each component material (inner layer members, outer layer members, and reinforcing materials are selected and used as appropriate depending on the type of hose). When the shaped hose is wound to form a hose shape, the rotating delivery bar 8 is arranged at an inclination by a certain amount of deviation, so that the formed hose is continuously delivered to the right. However, in this continuous molding, what is particularly necessary is ■
j[] Even in the sulfurized state, it must have sufficient strength so that when internal pressure is applied, the deformation will be limited to a level that is not harmful to use. ■ When pressurized steam acts inside the hose, there will be no leakage of steam. , to have sealing properties in an unvulcanized state.For the above condition (2), the required angle and number of layers of the reinforcing fiber material are set. Alternatively, an elastomer topping layer may be provided on both sides of an organic fiber material having heat-shrinkable strength, with a thick layer on the front side and a thin layer on the back side, or an elastomer topping layer may be provided only on the front side (but, these topping members may be placed under tension). , according to the application and composition, vulcanize to an appropriate degree of vulcanization, form an unvulcanized topping layer of elastomer on the rough back side, use such a self-forming member, and apply this to the inner surface H. It is possible to create a self-forming hose by wrapping the hose so that the vulcanized side is on the inner side, and wrapping it around the outer sheath layer to the desired width with the vulcanized side on the outside.
This continuous molding and vulcanization method is one of the preferred methods.

Note that the wire material such as steel wire is appropriately set depending on the purpose. Further, in addition to the unvulcanized topping layer, an unvulcanized sheet is also used as appropriate in order to improve adhesion.

For condition (2), sealing performance is improved by wrapping under tension so as to sufficiently press the unvulcanized portion, or by using an auxiliary pressure bonding device such as a roller.

The molded cylindrical body formed under the above-selected conditions is continuously sent out to the right at a constant speed, until it reaches a predetermined point of about 1 TrL to 2 m inside the fed out hose. A steam pipe 7 that supplies steam is set up, and an injection part J is formed near its tip.
Steam having a predetermined pressure and temperature is injected onto the inner surface of the hose.

Theory of the steam action range S necessary for vulcanization in Figure 2.

As shown in the diagram, when the pressure of the steam injected by the injection part J is PO and the temperature is to, and the steam action range where the pressure and temperature act is S, then at the left end point of the range S, , pressure and temperature drop rapidly. In theory, between the position of the injection part J and the point L,
Po and to are decreasing, albeit slowly. At point L, the steam temperature to decreases due to the low-temperature hoses successively laminated and molded, and at the same time, the temperature of the steam reaches P.

When the temperature decreases and finally drops below 100°C, the steam changes form and becomes a drain, eliminating the differential pressure with the outside. That is, the steam will not reach the position of the molded laminate. On the other hand, the steam ejected from the injection part J also reaches the point R at the right end of the steam action range S.
As at point L, the differential pressure disappears.

At this point, a wall plate with a smaller diameter than the inner diameter of the hose is installed on the steam pipe to remove pressure by natural cooling.
It can also be slowly cooled. In addition, in order to adjust the degree of vulcanization, the outside of the hose at points L and R can be cooled with water cooling Wo and Wl, as illustrated in Fig. 1, to adjust the range of steam action S. . In addition, a pipe is connected and extended to the end of the injection part J of the steam pipe, and a shielding plate with a diameter smaller than the inner diameter of the hose is installed on the support pipe, and as with point L, removal by natural cooling and slow cooling can be achieved. You can also. Furthermore, it is also useful to provide a rotary stopper outside the shielding plate at a portion where the hose is fed out from the molded portion using a support frame of a rotary bar.

Furthermore, in this continuous vulcanization method, the vulcanization conditions can be easily changed by changing the length of the steam acting range S. That is, the pressure po and temperature to of the steam ejected from the injection part J can be adjusted as needed, and the cooling rate can be adjusted with the water cooling WO1W1, so the vulcanization rate of the rubber material used or the diameter of the hose can be adjusted. It is also possible to change the optimal vulcanization conditions during continuous operation depending on the wall thickness, etc.

In addition, it is possible to discharge the steam-condensed condensate by tilting the vulcanization line in advance, but in this case, the condensate is generated at two points, L and R, so it can only be discharged in one direction. When tilted, it flows down between the steam action area S and, as a result, between 8 g degrees,
Since the pressure decreases, drain discharge using the inclined method requires that the member supporting the hose, such as the conveyor, be sloped so that both ends of the steam action range S are slightly lower.
It is desirable to discharge to both points L and R at low locations, but
In some cases, it may be effective to forcibly discharge the drain using a suction pipe installed inside the hose. In this continuous vulcanization method, unlike many conventional open vulcanization methods using vulcanization cans, steam does not come into contact with the outer surface of the hose, so there is no occurrence of surface roughness or the like. In addition, the steam action range S
Since steam pressure is applied from the inside in this area, there is no need to worry about dimensional stability, residual bubbles, or insufficient adhesive strength compared to pressureless vulcanization.

However, the improvement of dimensional accuracy in the steam action range S,
A continuous vulcanization operation may be performed by lightly wrapping a cloth as a stable protective cloth for heat retention, protection against external damage, etc. In this case, unlike open vulcanization, there is no contact with steam, so there is no risk of contamination. Alternatively, when the above-mentioned self-forming member is used, the hose is molded and sent out, and as it passes through the steam action range S, shrinkage force is applied due to heating, and a tightening force is formed, and the steam inside the hose is Since vulcanization is performed by firmly tightening the hose together with the injection pressure Po, the most preferable product can be obtained.

Next, the formation of the steam action area S will be described.

Forming speed of hose - VH (m/sec,) Required time for hose to be heated and vulcanized = TH (sec,) Distance subjected to heating (steam action range > 5 = VHXTH
(m) TH is selected in advance depending on the rubber composition and heating temperature, and T is adjusted by adjusting S and V)l.
H can be determined. Left end and right end R of steam action range S
If the temperature is 100° C. and the temperature of the injection part J is 140° C., there will be a temperature gradient of 40° C. between questions 0 and 1 and between J and R, respectively. Between 5 and 1 and J~
The time required for the temperature to drop by 40°C between R (injection part J
The time from the temperature to 100°C) is defined as td.

It is assumed that between J-L = Sz and between J''R = 3r.

VH=SA/ld 1St=V+Xtdl,',
td = Sz /VH, td is determined by the following formula.

θ...Hose inner surface temperature at left end and right end (100
℃) (Drain) θO...Initial temperature (temperature of injection part J) θ1...Hose outer surface temperature (cooling water temperature) If the above formula (1) is
Assign the next value.

VH = 5 mm/sec, = 0.005 m/Sec.

TH=600sec.

,°, S=5ux600=300mmWt=2m
m=0.002m α-12,3(mm2/m1n) =2.05X 1
05 (m'/sec) θ=100℃ θ0=140℃ θ1=5℃ ・・・・・・・・・(1 formula) However, the time from td...J temperature to 100'C (Sec,) Wt... Wall thickness of molded rubber hose (wall thickness) (1 m) α
...Temperature conductivity of molded hose (mm2/mi, n)
= 0.07815 (min) = 4.68
9 (sec, ) Therefore, when the area near the L point is cooled using cooling water at 5°C, steam at 140°C can be drained in about 5 seconds. Therefore, the required length of the steam action area S is as shown in the dimensional drawing of FIG. 3.

In addition, the distance of draining at the left end and right end R is
td = St /VH - 8t = td XVH = 4.7
x5=23.5 (mm>), that is, the range is considered to be approximately 24 mm.

Note that the inner surface of the unvulcanized rubber hose is in direct contact with the steam, and the temperature rise reaches the maximum temperature of the steam and can be sufficiently cured by 1q, but the outer surface of the hose can be heated by keeping it warm. , more efficient vulcanization conditions can be created.

However, heat retention from the outside is not the gist of the invention, but rather creating a pressure range for vulcanization from the inside.

Therefore, performing the cooling operation from the outside is not preferable from the standpoint of energy balance.

Therefore, the above-mentioned self-forming member can be effectively utilized. That is, it is preferable to use this material as appropriate for the outer surface, inner layer, or both layers. When this self-forming material is used for the outer covering layer, it is properly vulcanized in advance, so the outer surface will not soften, stick, or discolor like unvulcanized rubber. , it is very stable and therefore very easy to mold.

In addition, this vulcanized outer covering layer acts as a heat insulator and has the effect of preventing heat radiation from the inner surface, so that a good Karosulfur state can be obtained without heat retention from the outer surface or h0 heating. Furthermore, cooling work before and after the steam action area becomes easier. Furthermore, there is no need to wrap a stabilizing protective cloth around the outer surface, and very good continuous vulcanization can be achieved.

(Function) This method enables a simple manufacturing method that is completely different from conventional methods, and allows for continuous vulcanization.Theoretically, it is possible to produce hoses of any length from unlimited length to short or long hoses. ,
It is possible to carry out continuous vulcanization as desired in one assembly line without changing the work process, and is particularly suitable for small-volume, high-temperature heating fixing parts with a relatively short direct steam action range. This allows for efficient vulcanization.

Further, the vulcanization is performed under pressure and heat sequentially from the inner surface, resulting in good adhesion between the inner layer member and the outer layer member.

Furthermore, unlike dry heat, the hose is heated in a direct atmosphere of steam provided in the inner diameter of the hose, thereby preventing deterioration of the rubber due to oxidation. Also,
Since there is no pressure contact due to the tightening cloth, staining of the outer surface is prevented.

〔Example〕

Next, an example of using a self-molding member will be shown.

Rubber hose inner diameter 100mmφ Molding speed 5 mm/SeC.

7J01J Time 600 sec The hose structure is as shown in the partial cross-sectional view of the hose in Figure 4-1.
It is composed of an inner layer member 1, a steel wire reinforcing layer 6, and an outer layer.

Figure 4-2 is a structural diagram of the inner layer member unit of the above-mentioned hose. The required winding is formed into a wide strip (Strap). In this example, nitrile rubber is used, and heat-shrinkable nylon is used. One side of the fiber reinforced layer 3 made of fibers is topping processed and vulcanized under tension to an appropriate degree of vulcanization depending on the application to form vulcanized rubber 2, and the other side is unvulcanized. Must be a member topped with rubber.

In the figure, 2 is vulcanized rubber, 4 is unvulcanized rubber, 3 is a fiber reinforcement layer (nylon fiber is used in this example), and the thickness of the vulcanized rubber -
The thickness of the fiber reinforced layer is 0.2 mm, the thickness of the unvulcanized rubber is 0.4 mm, and the total thickness is 1 mm. When used as an inner layer member of a hose, the vulcanized rubber 2 side is wrapped around the inner layer of the hose.

Figure 4-3 is a structural diagram of the outer layer part vJ of the hose,
With the same configuration as shown in Figure 4-2, when used as the outer layer of a hose, the vulcanized rubber 2 side is wound on the outer surface of the hose, and the thickness is the same as that of the inner layer. It is something that uses something.

The hose is formed by continuously vulcanizing a molded and extruded hose, and in this example, the hose was formed using the installation shown in Fig. 1 as an example. The example shown in Fig. 4 is molded and vulcanized.

That is, in the figure, the former F has a large number of inclined delivery bars 8 for screws, as explained above.
This is a former F assembled on an assembly frame 9 whose periphery rotates, and the former F is driven by a driving body 10,
A steam pipe 7 for vulcanization is supported in the center of the assembly frame 9 in a heat-insulating manner.

On the frame F, first, take a strip of the required width of the inner layer member 1 and tighten it appropriately so that the vulcanized rubber 2 side is on the inside and the ends overlap each other by about 10 mm. It can be wrapped around with force. Next, the steel wire reinforcing layer 6 is adjusted to have a pitch of about 5 Qmm. However, the pitch and number can be changed depending on pressure resistance requirements, etc.

Next, the outer layer part +45 is wound on the steel wire reinforcing layer 6 so that it is on the inside of the unvulcanized rubber 4. The vulcanization is carried out by continuously heating the steam acting range S of the above-mentioned molded hose by steam injection at the 3000 mm pressure fixed part as described above.

〔Effect of the invention〕

Since the continuous vulcanization method of the present invention has the functions as described above, it is possible not only to provide particularly thin-walled long hoses at low cost, but also to provide hoses with a free length of medium diameter (40φ to 200φ).
A small hose suitable for use as a lightweight pressure-resistant hose for both delivery and suction can be obtained at low cost. In addition, since you can freely vulcanize the long hose you desire, you can
Continuous operation of many hoses becomes unnecessary. Furthermore, since large-scale vulcanization equipment is not required, a high degree of thermal efficiency can be obtained. In addition, good workability can be obtained since there is no need for a molding operation by ironing.

[Brief explanation of the drawing]

Figure 1 is a schematic explanatory diagram showing an example of the continuous vulcanization method for rubber hoses of the present invention, Figure 2 is a schematic reference diagram for determining the steam action range of the required length for continuous vulcanization, and Figure 3 is , a dimensional drawing showing an example of the steam action range of the required length, FIG. 4-1 is a partial sectional view of a hose showing an example of implementation, FIG. Figure-
3 is a structural diagram of the outer layer member of the same hose. Y... Inner layer member 3... Fiber reinforced layer...
Outer layer member 6...Steel wire reinforcement diagram 7...Steam pipe J...Injection part S...
Steam action range

Claims (1)

[Claims] (1) In a hose from which a hose molded body consisting of an arbitrary combination of an inner layer member, an outer layer member, a reinforcing layer, etc. is continuously fed out, a high temperature steam injection part by a steam pipe is set in the inner diameter part of the hose, A continuous vulcanization method for rubber hoses, in which a high temperature heating fixed part is set in front and behind the injection part, and has a steam action range of the required length required for vulcanization based on the hose delivery speed, vulcanization speed, etc., and is continuously vulcanized.