JPS58219035A - Manufacture of rubber tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] A wood invention related to a method for manufacturing rubber tubes.

In particular, the present invention relates to a new method for manufacturing rubber tubes for use in applications requiring a nearly perfect circular cross section, such as a flute lifter tube for the outer surface of a hose, which does not have a fiber reinforcing layer or the like.

Conventionally, direct vulcanization methods and mantle usage methods are known as methods for manufacturing rubber tubes that do not have a fiber reinforced layer or the like.

The direct vulcanization method is to extrude an unvulcanized rubber tube of a specified size using an extruder, pass through a cooling water tank and a take-up drum, and heat it to zero.
After arranging them on a winding pan and winding them up, steam vulcanization is performed directly in a vulcanizing can.

This manufacturing method consists of the step of removing the anti-adhesive agent in a washer.

This method +1. Because there is no shape-retaining means during vulcanization, the resulting rubber tube is extremely flat (7). Depending on the material, viscosity during vulcanization may cause significant stagnation (depending on the material), it may be necessary to apply an anti-adhesive agent, and a cleaning process to remove the anti-adhesive agent may be required after vulcanization.

This increases the number of steps and poses problems in terms of manufacturing efficiency and cost.

On the other hand, the mantle is melted, extruded into an unvulcanized rubber tube of specified size using an extruder, passed through a cooling water tank and a take-up drum, coated with anti-drop agent, and then lined up on a winding tray and wound up. This is a manufacturing method comprising the steps of cutting an unvulcanized column tube to a predetermined length, inserting the tube into a mantle whose surface has been coated with an anti-mold agent, and directly steam-curing the tube in this state using a vulcanizer or the like. This method is suitable for manufacturing short objects, but it requires a lot of dust, processing time, and material loss.It also requires a cleaning process to remove the anti-adhesion agent after vulcanization, and when applied to long objects. However, in the case of a rubber tube with a fiber-reinforced layer, it can be used for both purposes, but in the case of a rubber tube without a fiber-reinforced layer, there is the problem of difficulty in inserting and withdrawing the mantle. However, there are also problems in terms of manufacturing efficiency and cost.

The present invention was invented in view of the above circumstances, and is a method for manufacturing a rubber tube having a perfect circular cross section without a fiber reinforcing layer, etc., which simplifies the manufacturing process without using a core material, etc. To achieve this purpose, extruded unvulcanized rubber tubes are internally pressurized.

The step of covering the lead pipe with the outer surface of the core unvulcanized rubber cheap in close contact with the inner surface of the lead pipe, and the step of leaving both ends of the unvulcanized rubber tube covering the lead pipe open. The manufacturing method of the present invention includes a step of vulcanization, and the manufacturing method of the present invention involves extruding an unvulcanized rubber tube of a predetermined size using an extruder, passing it through a cooling water tank and a take-up drum, and applying a -C9 anti-adhesive agent. After the step of winding a predetermined length onto a winding tray, the inner surface of the unvulcanized rubber is sealed by sealing the open end of the tube, for example, and blowing air at a constant pressure from the open end of the other end. Pressure is applied and the lead pipe is opened with the outside of the unvulcanized rubber tube in close contact with the inner surface of the lead pipe. 7. After vulcanization, there is a step of splitting the lead pipe metal with a split lead machine to obtain the desired gono tube.

In the present invention, air is used to pressurize the inside of the unvulcanized rubber tube, and the pressure is adjusted using a t-regulator. That is, the air pressure varies somewhat depending on the thickness of the rubber cheek.

If the wall thickness is about 1 to 5 mm, 1 usually 0.15 to 0.25.
- is appropriate, and the pressure is adjusted within this range using a regulator. Within the above pressure range, the diameter of the unvulcanized rubber teak is d1. 5 to 20% of the inner diameter of the lead pipe
The pressure is preferably increased to an extent of 8 to 15%, so that the outer surface of the unvulcanized rubber tube is brought into very good contact with the inner surface of the lead pipe. If the air pressure is lower than the above range, the internal pressure will be insufficient and the outer surface of the unvulcanized rubber tube and the inner surface of the lead pipe will become trapped.

The perfectly circular cross section will not be rounded, resulting in a deformed rubber tube. If the air pressure is higher than the above range, the internal pressure will be too high and the unvulcanized rubber tube will become thick.

This causes fluctuations, and a rubber tube having the required thickness Lqj IN cannot be obtained. The regulator is intended to maintain the internal pressure at a constant value, θ11<, as described above, at any point in time when the lead pipe is nodal, that is, there is no uneven thickness over the entire view of the rubber tube, and the oblateness is extremely small. This makes it possible to create a rubber tube with a perfectly circular cross section.

That is, in order to obtain the desired rubber tube, maintaining the internal pressure as well as the rate of lead application are important factors, and it is appropriate that one charge of a 100-150'M material should take no more than 15 minutes. be. ■If the charging time becomes longer, the meat will become larger in the initial stage of lead exposure.

At the final stage of lead coating, the pieces tend to be small, although a perfectly circular cross section can be obtained over the entire length of the rubber die.

The variation in wall thickness becomes large, which is undesirable. In addition, the inner diameter of the rubber tube at the beginning of the lead, τj modulus, is an inherent characteristic of the leaded machine in which the inner diameter of the lead pipe at the beginning of the lead is small.
Measure-c: Extrude only the female lead pipe a little and cover it with the rubber tube once the dimensions are stable. Furthermore, the inner diameter of the rubber tube at the end of the corrugated lead is small, and the end is to be cut off without being pressurized.This is an unavoidable part, but the loss due to this is 1 to 10% per charge. 2m
It can be kept to a certain extent.

In addition, in the vulcanization process, the unvulcanized rubber dump is vulcanized with both ends open to improve the flow of two steams.
C is used for uniform vulcanization.

Next, one effect of the present invention is the following F.

(1) Rubber tubes with a perfectly circular cross section can be manufactured without using a core material such as a mantle.

Manufacturing equipment and processes can be simplified.

(2) Thin wall: Even with a single layer square, it is possible to manufacture a rubber tube with an extremely small oblateness and a perfect circular cross section at 1°. (3) It can also be applied to long items, so manufacturing cost is 0. is cheap.

(4) During the lead coating process and the vulcanization process, there is no contact between the rubber tubes and their inner surfaces, resulting in significant adhesion.1. The scope of application can also be expanded to the case of interest.

Furthermore, since there is no need to use an anti-adhesive agent, the manufacturing equipment and process can be simplified.

Hereinafter, the present invention will be explained in detail by way of Example-1.

Example 1 N l) Trill rubber in R shown in formulation A in Table 1
The mixture was made using an extruder, with an inner diameter of 14.0 '-%', ', m,
An unvulcanized rubber tube with an outer diameter of 22.8 ± 0.3 mm and a wall thickness of 4.4 ± 0.1 M was extruded at an extrusion speed of 8 MAj-, passed through a cooling water tank and a take-up drum, and was coated with an anti-adhesive agent. (Zinc Stearate) was applied while winding up 120 m on a winding tray. Then, open one end of this unvulcanized rubber tube! Inner diameter 22.5mm, outer diameter 3Q, 5M, wall thickness 4.5mm, with air blown from the opening at the other end and a load applied to the inside.
A 0-layer lead pipe was coated with a lead covering machine. During this time, the air pressure was maintained at 0.20° by the regulator, and the outer surface of the unvulcanized rubber peak was in close contact with the inner surface of the lead pipe. Next, the leaded unvulcanized rubber tube was placed in a TIII sulfur can by releasing the seal on one end that had been sealed earlier, leaving both ends open, and steam vulcanizing at 145°C for 40 minutes. All lines fc.

After that, it was taken out from the vulcanizing can and left to cool, and then the coated lead pipe was split with a split lead machine to obtain a rubber tube.

This rubber cheek was cut in the radial direction every 10 pn, and the inner diameter, outer diameter, and wall thickness were measured [7]. The results are shown in Table 2.

In addition, the internal pressure shown in Table 1 is applied to the unvulcanized rubber tube by air.
Full load was only 0. As is clear from these results, it has a nearly perfect circular cross section over its entire length. It was found that a rubber chunk with a small aspect ratio was obtained.

Table 2 10+2 Inner diameter 14.5-o, 6mm, Outer diameter 22, 5+7. :
Excludes data for XNR, wall thickness 4.5±0.8 (at the start of lead coating) and 120 fPI (w1 lead over time).

Example 2 The El''I)M (ethylene-propylene-diene rubber) formulation shown in B formulation in Table 3 was processed using an extruder to produce an inner diameter of 27.000-3vR, an outer diameter of 32.0±Q, 4M, and a wall thickness. 2.5
Extruded at ±0.1 armpit, 150m in the same process as Example 1
Objects were leaded. Lead conditions are air, pressure 0.20η,
Lead pipe inner diameter 30.5 original, outer diameter 38.8 joint, meat grain: 4.15
M, the lead-covering speed was 12 m or above.

Thereafter, vulcanization was performed in the same process as in Example 1 (vulcanization conditions 145
A rubber tube was obtained through a 129% lead process (°C x 35 minutes). The rubber tube was cut in the radial direction every 0 m, and the inner diameter, outer diameter, and wall thickness were measured.

The results are shown in Table 4. In addition, the outer diameter of the unvulcanized rubber tube before being leaded is between 33.5±0.5 when pressurized with air.
While under ship, the diameter was 33.8±0.3M at around 40m and 34.1cm at around 80m, and the change in diameter was small.
,.

As is clear from these results, it has a nearly perfect circular cross section over its entire length. A rubber chunk with a small aspect ratio was obtained. The average value of the flattening ratio was 5.6% based on the results of measurements at 6 locations every 201 times.

However, l-2゜ Table 3 Table 4 (Note) Rubber tube specification dimensions Inner diameter 25.5±1.0mm, outer diameter 30.5±1.5mm.

Wall thickness: 2.5±0.3 Kumaichi Kasa Excludes data for □m (at the start of lead coating) and 150jf (after lead coating).

It was extruded to a thickness of 3.8±o and tm, and a 120 m piece was leaded in the same process as in Example 1. Lead condition is air pressure 0.1
8'vJ, lead pipe inner diameter 3Q, 5 Mm, outside 537.3
``m!The wall thickness was 3.4M, and the lance speed was 10m/min.After that, vulcanization was carried out in the same process as in Example 1 (vulcanization conditions were 145℃
x 35 minutes) A tube was obtained through one step.

Similarly, the rubber tube was cut into 10mm pieces in the radial direction, and the inner diameter, outer diameter, and thickness Iv were measured.1. That's the result.

It has a nearly perfect circular cross section. A rubber tube with extremely small oblateness was obtained. The data are shown below.
+ Average value of total 5 locations)

Claims (1)

[Claims] The process of coating the lead pipe in close contact with the lead pipe?
11. A method for manufacturing a rubber tube, comprising the step of vulcanizing an overturned unvulcanized rubber tube with both ends open.