JPH01229617A - Coiled rubber tube, manufacture thereof and mandrel for manufacturing coiled rubber tube - Google Patents

Abstract

PURPOSE:To obtain a compact coiled rubber tube, the strain of which is slight, by a method wherein the coiled rubber tube is primarily vulcanized under the state of being coiled in normal helix and, after that, secondarily vulcanized under the state of being coiled in reverse helix and finally rewound in normal helix. CONSTITUTION:A watersoluble coagulating agent film is formed on the surface of a coarse- pitched coiled mandrel over the domain ranging from the tip straight part 13a to the rear end straight part 13b of the mandrel. A rubber layer 2 is formed by immersing the mandrel in a latex tank. When the latex is natural rubber, for example, the rubber layer is primarily vulcanized by being heated at 80-100 deg.C for 3-5hr. As a result, a rubber tube 2 hardens to some extent and can be demounted from the mandrel 1 for handling and the pitch of the demounted tube results to be smaller than that of the mandrel by about 5%. Concretely, water is passed under pressure through the rubber tube 2 so as to wash off a part of the coagulating agent in order to draw the rubber layer 2 out of the mandrel 1 by turning it. The rubber tube 2 is rewound in reverse helix, immersed in hot water having a temperature of about 60 deg.C for about 2 days in order to remove the remaining coagulating agent and, after that, dried so as to be secondarily vulcanized by heating at 80-100 deg.C for 3-5hr. Finally, by rewinding the rubber tube again in normal helix, a fine-pitched coiled rubber tube is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a coiled rubber, a method for manufacturing the same, and a mandrel for manufacturing the coiled rubber.

(Technical Background of the Invention) Hollow, coiled rubber tubes are elastic and stretchable, and are therefore used as conduits for medical instruments such as blood pressure monitors.

Such a coiled rubber tube is produced by preparing a coiled mandrel 1 with a coarse pitch (indicated by d) as shown in FIG. was vulcanized to form tube 2 (
(see Figure 2), then the mold release box 3 as shown in Figure 3.
The rubber tube 2 is sandwiched between the sponges 4a and 4b provided on both the upper and lower surfaces, and the supporting portion 11 of the mandrel 1 is
The mandrel 1 is removed from the rubber tube 2 by rotating it counterclockwise manually or by an electric motor.

The rubber tube 2 in this state is a coiled rubber tube with a coarse pitch (indicated by d in the figure) as shown in FIG. This is because when removing the rubber tube 2 from the rubber tube 1, if the pitch is too small, it will be difficult to separate.

However, the coiled rubber tube 2 with such a coarse pitch is not only disadvantageous for transportation, etc., but also takes up a large volume when used, and is also undesirable from a design point of view. At present, the winding is reversely wound to reduce the pitch interval and the length direction -j law as shown in Fig. 4.

When the coiled rubber tube 2 is reversely wound in this manner, it is clear that distortion occurs in the coiled rubber tube 2, but in this case, there is a drawback that deterioration occurs more than the portions where the distortion is greater.

Furthermore, straight portions 3a, 3 are provided at both ends of the coiled rubber tube to advantageously connect a medical device 823 as shown in FIG.
The coiled rubber tube 2 having the shape b had the disadvantage that when reversely wound, the straight portions 3a and 3b are oriented inward in the elongated direction as shown in FIG.

(Summary of the Invention) The present invention has been made in view of the above-mentioned points, and although the pitch is small, it is not in a reverse winding state, and therefore, even when a straight part is provided, the straight part is directed outward in the longitudinal direction. Coiled rubber tubes and their manufacturing methods, as well as coiled rubber tubes like this one! ! ! It is characterized by providing the deposit for the construction.

In order to achieve the above object, the coiled rubber tube according to the present invention is a coiled rubber tube that is spirally wound in a predetermined direction, and is primarily vulcanized while being wound in the predetermined direction.
It is characterized in that it is secondarily vulcanized in a reversely wound state to the above direction.

Furthermore, the method for manufacturing a coiled rubber tube according to the present invention includes: (a) forming a water-soluble coagulant coating on the surface of the coiled mandrel having a rough pitch; (b) a coagulant coating on the coiled mandrel. a step of attaching rubber latex to the surface; (c) a step of primary vulcanization of the rubber latex; (d)
After the vulcanization, a step of dissolving a part of the water-soluble coagulant and pulling out the coiled mandrel; (e) a step of rewinding the formed rubber tube in the opposite direction to the winding direction; (f) a step of rewinding the rubber tube in the opposite direction to the winding direction; The method is characterized by including a step of secondary vulcanization of the tube, and (g) a step of unwinding the reversely wound rubber tube.

Further, the coiled rubber manufacturing mandrel according to the present invention has a straight part at the tip and rear end of the mandrel body wound into a coil, and the straight part at the tip is detachable. It is characterized by

According to the present invention, primary vulcanization is performed in a 1lIi wound state and secondary vulcanization is performed in a reversely wound state, so that returning to the sequentially wound state after the secondary vulcanization brings about the advantage that the pitch interval becomes smaller. The reason for this is not clear, but by performing secondary vulcanization in a reverse-wound state, there is a force that tries to maintain the reverse state, and a force that attempts to maintain the forward-wound state (-which occurs during secondary vulcanization). occurs, and when the forward winding state is established, the force that tries to maintain the reverse winding state becomes a force that reduces the pitch.In the above case, basically, in order to return to the forward winding state, the reverse winding state Compared to the above, the distortion remaining in the rubber tube is significantly reduced and the durability is improved.In addition, in the case of a rubber tube with a straight section, the straight section returns to its original state. It has the advantages of easy orientation, easy connection of devices, and excellent design.

Further, the mandrel according to the present invention has the advantage that a coiled rubber tube having straight portions at both ends for attachment to equipment or the like can be easily produced.

(Detailed Description of the Invention) First, a method for manufacturing a coiled rubber tube according to the present invention will be described.

In the present invention, first, (a) a water-soluble coagulant coating film is formed on the surface of a coiled mandrel with a coarse pitch.

That is, a mandrel 1 as shown in FIG. 1 or a mandrel 1 having linear portions 13a and 13b at both ends of a coiled portion 12 as shown in FIG. Forms a coating film.

As shown in FIG. 7, the coiled rubber tube manufacturing mandrel according to the present invention has straight portions 13a and 13b at both ends of the coiled portion 12, and among these straight portions, the tip straight portion 13a is It is removable.

That is, as shown in FIG. 8, for example, the distal end 12a of the coiled portion 12 is provided with a female screw 121, and the linear portion 13a is provided with a female screw 131, so that the two can be screwed together or screwed together. It can be attached and detached by taking it off.

When manufacturing a coiled rubber tube using such a mandrel 1, the surface of the coiled mandrel with a coarse pitch from the tip straight part 13a to the rear end straight part 13b as shown in FIG. A water-soluble coagulant coating is formed on the surface.

The pitch of this mandrel 1 (same as d shown in FIG. 2) is preferably 10 to 30111ffi.

If it is less than 10 nn, the pitch will be too small, making it difficult to extract the rubber tube 2 in the extraction process described later, and there is a risk that adjacent rubber pieces will stick together. On the other hand, if it exceeds 30 ornaments, This is because even if the rubber tube is subjected to secondary vulcanization in a wound state, the pitch becomes relatively large, and there is a risk that the rubber tube will not be compact.

As the above-mentioned water-soluble coagulant, basically any one can be used as long as it has been conventionally used in the production of rubber products in which latex is attached to molds of this type.

The method of forming such a water-soluble coagulant coating on the mandrel 1 is not strictly limited, and can be carried out, for example, by immersing the mandrel in an aqueous coagulant solution.

After being immersed in the water-soluble coagulant in this manner, it is dried to form a coating film on the surface of the mandrel 1.

Next, according to the present invention, (b) rubber latex is adhered to the coagulant coated surface of the coiled mandrel.

The above mandrel is immersed in a latex bath. When immersed in the rubber latex liquid in this manner, the rubber colloid adheres to and condenses on the coating surface of the mandrel 1 due to the action of the coagulant, forming a rubber layer 2 as shown in FIGS. 2 to 9. .

After forming the rubber layer 2 in this way, (c) the rubber layer 2 is
, primary vulcanization of latex.

By performing the secondary vulcanization in this manner, the rubber layer 2 is cured to some extent, and can be removed from the mandrel 1 and handled. In the present invention, the rubber tube is reverse-wound and secondary vulcanized. , it is necessary to make the pitch smaller when this is wound in order. Therefore, this post-vulcanization is
This becomes a major factor in the present invention.

For example, when the latex is natural rubber, this post-vulcanization is preferably carried out by heating at a temperature of 80 to 100° C. for 3 to 5 hours. If the temperature is less than 80°C, the secondary vulcanization may not be sufficient and may take too much time.
On the other hand, if the temperature exceeds 100°C, there is a risk that the surface will crack or be completely cured.

If the vulcanization time is less than 5 hours at 80℃, there is a risk that the vulcanization will not be sufficient.On the other hand, if the vulcanization time exceeds 3 hours at 80℃, the vulcanization will be overdone, resulting in cracks on the surface or complete curing. There is a risk that it will happen.

Through this post-vulcanization, the pitch of the rubber tube 2 is approximately 5%.
The front and back become smaller.

After post-vulcanization in this manner, (d) part of the water-soluble coagulant is dissolved and the coiled mandrel is pulled out.

In this case, pressure is applied from the tip 2a to the rear end 2b of the rubber tube 2 as shown in FIG. 2, or from the straight portion 3b of the rear end 2b of the rubber layer 2 as shown in FIG. Water is passed through the rubber tube 2 to wash away a portion of the coagulant and break the tight contact between the inner wall of the rubber tube and the mandrel 1.

Thereafter, the mandrel 1 is placed in a release box 3, and while the rubber layer 2 is held down by the sponges 4a and 4b, the mandrel 1 is rotated manually or mechanically to remove the rubber layer 2.

In this case, since the pitch of the coils of the mandrel 1 is coarse, the rubber tube 2 can be easily removed.

In addition, when using the mandrel of the present invention having a straight part, at least the tip straight part 13a is unscrewed (see FIG. 8) so that this straight part 13a does not interfere with the rotational withdrawal of the mandrel 1. , the rubber tube 2 is separated from the mandrel 1.

In this case, press the rubber part of the straight part 13b by hand three times in advance.
If the crest is pushed into the center metal and installed in the mold release box 3 in this state, the rear end straight portion 13b will not interfere with the mold release, making the release even easier.

After removing the rubber tube 2 in this way, cut off the straight part 3a (the tip 2a in the case of FIG. 2) of the mandrel 1 of the rubber tube 2 in the distal direction a little so that the hole in the rubber tube 2 passes through it. After this, pressurized water is passed through the tube 2 to thoroughly wash out the coagulant.

After washing away the coagulant in this way, (e) rewind the rubber tube in the opposite direction.

For example, if you fix a rubber tube to a rotating shaft connected to an electric motor, hold the other end lightly, and rotate the rotating shaft in the opposite direction to the winding direction (for example, clockwise), the winding will be reversed. Become. The state at this time is similar to that shown in conventional figures 4 to 6.
This is the state shown in the figure.

In this situation, (f) Secondary vulcanization of the rubber tube.

Such secondary vulcanization is carried out by, for example, immersing the rubber tubes in hot water of about 60° C. for about two days to remove the remaining coagulant, and then arranging the rubber tubes 2 laterally in a dryer. Do this at the same time as drying the water.

The conditions for secondary vulcanization at this time are preferably 80 to 10
It is best to carry out the treatment at 0°C for 3 to 5 hours. If the vulcanization (drying) temperature is less than 80°C, there is a risk that it will not be sufficiently vulcanized, while if it exceeds 100°C, the surface may crack or be completely cured. It is.

After secondary vulcanization in this way, optional surface treatment is performed, (■) Rewind the rubber tube.

In this way, by rotating the rubber tube with the motor in a clockwise direction, which is the exact opposite of when winding it backwards, and unwinding it, the pitch of the coiled part is shorter than in the state shown in Figure 5, as shown in Figure 10. It can be made of coiled rubber tube.

Such a coiled rubber tube according to the present invention is primarily vulcanized in the forward-wound state and second-vulcanized in the reverse-wound state.

The pitch d of this coiled rubber tube 2 is preferably 30 mm or less. This is because if the pitch exceeds 30M, the coiled rubber tube will not be relatively small, which may cause problems during transportation and use.

EXAMPLE A coiled rubber tube was manufactured using a mandrel 1 made of a highly hard stainless steel mesh wire with a diameter of 3 ma+ and having straight portions at the tip 1a and the rear end 1b as shown in FIG. 7.゛The pitch of the coiled partial tube of this mandrel is 16 mm, and the diameter is 17 mm.
mm, and the length was 800M. Further, in the straight portion 3, the core metal light end portion 3a had a thickness of 30ffiffi, and the rear end portion 3b had a thickness of 50ffiffiffi.

Add 100 kg of methanol, 50 kg of calcium chloride, 10 kg of calcium nitrate, and 50 kg of bentonite to the above core metal 1.
After immersing it in an aqueous coagulating solution consisting of 1 kg, it was slowly pulled up to form a coagulant coating film around the mandrel 1 over the range from the tip 1a to the rear end 1b of the mandrel 1. The core metal 1 was placed in a dryer at 90° C. for 10 minutes to completely remove the alcohol in the coagulant and dry the coating film.

Next, the mandrel 1 having the coating film was immersed in a rubber latex bath and left for about 17 minutes to solidify the rubber latex on the surface of the coating film. Thereafter, the mandrel 1 was pulled up from the rubber latex bath at a slow speed of 180 m/min.

Next, the core metal 1 was placed in a dryer heated to about 90 to 100° C. for about 90 minutes to vulcanize the rubber latex (secondary vulcanization) (see FIG. 8).

After that, pressurized water is flowed into the rubber tube 2 from the proximal portion 2b of the rubber layer 2 to wash away bentonite, which is a coagulant.
After breaking the tight contact between the rubber tube 2 and the mandrel 1, the mandrel 1 was rotated while holding down the rubber layer 2, and the rubber tube 2 was removed.

After sufficiently washing away the coagulant, the rubber tube 2 was wound in the opposite direction (as shown in FIG. 6).

In this reverse-wound state, 20 tubes were immersed in hot water at about 60°C to remove the coagulant, especially calcilyl and salt, and then placed horizontally in a dryer at about 70°C. It was left to stand for 3 hours to perform secondary vulcanization.

Add 50% hydrochloric acid to 1000 ffi of water to the dried rubber tube.
The surface rubberized film was chlorinated by immersing it in a solution containing 0g of powder and 500g of highly refined powder for 5 minutes.
001 was immersed in a solution of 500 g of 25% ammonia water for 5 minutes to neutralize it, and then placed in a water bath to thoroughly wash away the chemicals.

After draining the water, it was immersed in an approximately 0.1% aqueous alcohol solution, immediately taken out, and left in a dryer at around 70'C for approximately 3 hours to dry thoroughly.

The dried rubber tube was rewound to produce a sequentially wound coiled rubber tube according to the present invention.

As shown in FIG. 10, the manufactured rubber tube has a smaller pitch of the coiled portion than the one originally removed from the mandrel 1 (see FIG. 5), and the interval d1 between the pitches is 8IIlfl+
Met. In addition, the straight portions 3a and 3b face each other outward in the longitudinal direction, which facilitates attachment to equipment and the like.

(Effects of the Invention) According to the present invention, since vulcanization is performed in a sequentially wound state and a reversely wound state, a coiled rubber tube can be manufactured in a sequentially wound state and with a small pitch. Therefore, there is an advantage that a compact coiled rubber tube with small distortion can be easily provided. Further, by using the mandrel according to the present invention, there is an advantage that a coiled rubber having straight portions provided at both ends of the coil portion can be easily manufactured. Furthermore, in the case of coiled rubber tubes with straight parts for mounting equipment as described above, even if the pitch is small, the straight parts can be manufactured in such a way that they face in opposite directions, making them highly functional. There is also the advantage of being a target.

[Brief explanation of the drawings] Fig. 1 is a side view of the core metal when manufacturing coiled rubber;
Fig. 2 is a side view when rubber latex is attached to the mandrel, Fig. 3 is a perspective view of the release box, Fig. 4 is a side view when the gol and tube are reversely wound; Figure 5 is a side view of a coiled rubber tube having a straight section, Figure 6 is a side view of the coiled rubber tube when reversely wound, and Figure 7 is a side view of the coiled rubber tube having a straight section when manufactured. A side view of the mandrel used, FIG. 8 is an enlarged view of the straight end portion of an embodiment of the mandrel of the present invention, FIG. 9 is a side view when rubber latex is attached to the mandrel, and FIG. 10 is a side view of the mandrel used. The figure is a side view of an embodiment of a coiled rubber tube according to the present invention. l... Core metal, 13a... Straight end portion, 13b
... Rear end straight section, 2... Rubber tube, 3a, 3b...
Straight section of rubber tube. Applicant's agent Masaki Amemiya Figure 1 Figure 6a Figure 7

Claims (5)

[Claims] (1) In a coiled rubber tube spirally wound in a predetermined direction, primary vulcanization is performed while the tube is wound in the predetermined direction, and secondary vulcanization is performed while the coil is wound in the opposite direction. A coiled rubber tube featuring: (2) The coiled rubber tube according to claim 1, wherein straight portions are provided at both ends of the rubber tube. (3) (a) Step of forming a water-soluble coagulant coating on the surface of the coiled mandrel with a coarse pitch; (b) Step of attaching rubber latex to the coagulant coated surface of the coiled mandrel; (c) ) Primary vulcanization of the rubber latex; (d) After the vulcanization, part of the water-soluble coagulant is dissolved and the coiled mandrel is pulled out; (e) The formed rubber tube is wound in the opposite direction. (f) a step of secondary vulcanization of the reversely wound rubber tube; and (g) a step of unwinding the reversely wound rubber tube. (4) (a) It has a straight portion at the tip and the rear end, and the straight portion of the tip is at least removable.
The coiled core according to claim 3, further comprising the step of forming a water-soluble coagulant coating on the surface of the linear mandrel having a coarse pitch from the front end to the rear end. Rubber manufacturing method. (5) Manufacture of a coiled rubber tube characterized in that the mandrel main body wound into a coil has a straight portion at the tip and rear end, and the straight portion at the tip is detachable. Caution money.