JP4322603B2 - Method for producing drain tube made of silicone rubber elastic body with ribs on inner surface - Google Patents

Description

  The present invention relates to a method of manufacturing a drain tube that mainly discharges blood or body fluid that exudes from a wound after surgery.

  Drain tubes are widely used as surgical instruments for draining blood and body fluids that exude from the wound after surgery, and products with various inner and outer diameters and shapes are commercially available.

  Since the drain tube is generally required not to be blocked by a kink when it is subjected to force by the surrounding tissue during indwelling, a tube with a certain hardness is used. It had been. For example, a method of forming a resin material having a relatively high hardness, or embedding a linear body has been performed. However, if the drain tube has a high hardness, there is a problem that the distal end portion of the drain tube damages an organ, a blood vessel or the like when inserted into the body and placed, or the surrounding tissue is compressed and damaged in the placed state.

  On the other hand, a tube having a plurality of holes so that drainage can be performed even if a kink occurs in the tube, a tube having a linear rib on the inner surface, and the like have been developed.

  For example, a drain tube having a unique cross-sectional shape is known (for example, see Patent Document 1).

  Moreover, what embedded the helical linear body for kink prevention is known (for example, refer patent document 2).

In addition, there is known a rib having a unique cross-sectional shape and intended to prevent kinking and flow of body fluid (for example, see Patent Document 3).
JP-A-8-112346 JP 7-328123 A JP 2000-237302 A

  However, when the drain tube with ribs on the inner surface is formed by the conventional method, sink marks are generated on the surface of the drain tube corresponding to the position where the ribs are present, and the rib tip is sharpened at the acute angle as required. There was a problem that it was difficult to form.

  If sink marks are present on the surface of the drain tube, the frictional resistance becomes large when placed in the body, which is not preferable. This is not preferable particularly when the rib is formed in a spiral shape.

  In addition, when the drain tube receives a kink, it is easy to ensure the flow rate of the fluid flowing through the inside, and therefore it is desired that the tip of the rib be sharp.

  The present invention is to produce a drain tube made of a silicone rubber elastic body having a rib on the inner surface, which has excellent surface properties that are unlikely to cause sink marks on the surface and can be formed with a desired sharp inner rib. It is an object to provide a method.

As a result of intensive studies by the inventors in order to solve the above problems, in a method of manufacturing a drain tube made of a silicone rubber elastic body having ribs on the inner surface, one or more substantially V-shaped grooves using a crosshead die A hole that penetrates the mandrel is drilled, and a part of the groove is a small hole that reaches the through hole of the mandrel. The present inventors have found a method for producing a drain tube, characterized by injecting silicone raw rubber so as to flow on the outer surface of the mandrel from a substantially vertical direction of an extrusion line using a feeding device. According to this, it becomes possible to easily manufacture a drain tube having excellent surface properties and having the inner rib in a desired pointed state.

  Further, since the groove formed in the mandrel is a spiral groove, a drain tube made of a silicone rubber elastic body provided with a spiral rib on the inner surface can be manufactured in the same manner.

  By using a drain tube made of a silicone rubber elastic body provided with ribs on the inner surface (various shapes are possible, but spiral ribs are particularly preferable), a drainage bag or a drainage pump is connected to this, When suctioning and actively draining pus, body fluids and blood, and mucus or solids such as pus and blood clots from the inside of the living body to actively discharge the body fluid, etc. Can be discharged reliably.

  For this reason, it is possible to reduce the time burden imposed on the patient, and accordingly, the patient's pain can be reduced, and the preventive effect on the infectious disease is enhanced. Furthermore, it is effective for the medical staff to reliably discharge the body fluid in a short time.

  Moreover, when fixing to a body wall by sewing etc., there exists the characteristic that the lumen | bore of the said part is hard to be crushed.

  In addition, the drain tube is made of a silicone rubber elastic body, so it is flexible, and the distal end of the drain tube is less likely to damage organs and blood vessels, and after placement, the surrounding tissue is compressed with the hardness of the drain tube. Hard to damage.

  The present invention makes it possible to easily manufacture such a drain tube made of a silicone rubber elastic body provided with ribs on the inner surface with good surface properties and further with the ribs on the inner surface being in a desired pointed state.

  The present invention relates to a method of manufacturing a drain tube made of a silicone rubber elastic body having ribs on the inner surface, and using a crosshead die, a mandrel having one or more grooves formed therein is substantially parallel to the extrusion line. The present invention relates to a method for producing a drain tube, characterized by injecting silicone raw rubber so as to flow on the outer surface of the mandrel from a substantially vertical direction of an extrusion line using a resin supply device.

  The present invention is characterized by using a crosshead die having a structure in which a mandrel is allowed to pass substantially parallel to the extrusion line and silicone raw rubber is injected in a direction substantially perpendicular to the extrusion line.

  Here, being substantially parallel to the extrusion line means being substantially parallel to the direction in which the silicone raw rubber (with a mandrel) molded into the shape of the drain tube is discharged. Further, the substantially vertical direction of the extrusion line means that it is substantially perpendicular to the direction in which the silicone raw rubber (with a mandrel) molded into the shape of the drain tube is discharged. Incidentally, “substantially parallel” and “substantially perpendicular” mean that the angle may be changed within a range that does not interfere with the gist of the present invention.

  In the present invention, a desired drain tube shape is formed on the mandrel by injecting silicone raw rubber so as to flow on the outer surface of the mandrel.

  Here, the silicone raw rubber means a state before being cured to form a silicone rubber elastic body. As a method for curing, various curing methods can be used as long as they do not interfere with the gist of the present invention. Generally, a small amount of a vulcanizing agent is previously contained in a silicone raw rubber, and a drain is placed on a mandrel. A method of curing after heating as a shape of a tube is used. Thereafter, the silicone rubber elastic body is removed from the mandrel to form a drain tube.

  The mandrel used in the present invention must have at least one groove. This groove makes it possible to form a rib on the inner surface of the drain tube. In the present invention, a silicone raw rubber is shaped into a desired drain tube shape on a mandrel in which grooves are formed, and curing is performed in this state. In addition, it is possible to form the ribs on the inner surface with a desired sharpness.

  Below, the manufacturing method of the drain tube of this invention is demonstrated in detail using an example.

  FIG. 1 is a side view of a mandrel having a plurality of substantially V-shaped spiral grooves disposed on the surface, and a hole penetrating the mandrel is formed at the center. Furthermore, a mandrel one end B is provided with a one-touch detachable joint, and the other end is provided with an arcuate protrusion C. Various materials can be used as the material of the mandrel, but a metal that is light and hardly deforms is preferable.

  FIG. 2 shows the A-A 'cross-sectional shape of the mandrel of FIG. 1, and a plurality of grooves (eight in the drawing) are formed on the surface. A part of the groove is a small hole D that reaches the through hole of the mandrel. In addition, the surface of the mandrel is coated with polytetrafluoroethylene. If the small holes D are provided, the heat vulcanization process is completed, and when the drain tube formed as a silicone rubber elastic body is released from the mandrel, it can be used as an air outlet that facilitates release. It is preferable to provide it. Similarly, polytetrafluoroethylene is preferably coated in order to facilitate the release of the drain tube.

  The cross-sectional shape of the spiral groove formed on the mandrel surface is substantially V-shaped in FIG. 2, but the shape is not particularly limited. For example, a substantially V shape, a substantially U shape, a substantially semicircular shape and the like can be mentioned. However, since it is easy to secure the flow rate of the fluid flowing inside when the drain tube receives a kink, it is more preferable that the tip of the rib is sharp (ie, substantially U-shaped, substantially semicircular, etc. Is also preferably substantially V-shaped). This is considered to be because when the drain tube kinks and the tip of the rib comes into contact with the inner surface of the drain tube, the sharper the tip of the rib, the easier it is to create a gap through which fluid flows.

  Furthermore, the groove formed in the mandrel is preferably a spiral groove rather than a linear groove with respect to the axial direction of the drain tube from the viewpoint of a balance between kink resistance and flexibility. Further, when forming a spiral groove on the mandrel surface, that is, when providing a rib on the inner surface of the drain tube, an angle of 10 ° or more and 80 ° or less is set with respect to the longitudinal direction of the drain tube. It is preferable that an angle of 30 ° or more and 70 ° or less is further provided. This is because if the angle formed by the spiral rib with respect to the longitudinal direction of the drain tube is small, the flexibility tends to be impaired, while if too large, the kink resistance is likely to be impaired. Furthermore, the depth of the spiral groove applied to the mandrel can be set as appropriate, but as described above, if it is too shallow, the kink resistance is easily impaired, and if it is too deep, the flexibility is easily impaired.

  An example (sectional view) of a drain tube manufacturing apparatus using the crosshead die used in the present invention is shown in FIG. As the resin supply device 1 for injecting the silicone raw rubber from the substantially vertical direction of the extrusion line, for example, an ordinary extruder is used. A crosshead die body 3 is placed at the tip of the resin supply device 1, and a mandrel insertion portion 2, a die 4 and the like that form a mandrel passage portion 5 are arranged. The mandrel insertion portion may be manufactured by cutting out a tetrafluoroethylene block, or may be formed from a metal material divided into two parts, and the mandrel passage portion 5 may be tetrafluoroethylene or tetrafluoroethylene coating may be applied. . The mandrel passage portion 5 needs to have a diameter slightly larger than the outer diameter of the mandrel used. In addition, the silicone raw rubber flow surface 6 of the mandrel insertion portion preferably has a structure such as a spiral flow path so that the silicone raw rubber can be uniformly coated with the mandrel and shaped into the shape of the drain tube ( Not shown).

  The inner diameter of the die and the outer shape of the mandrel determine the approximate wall thickness of the drain tube. The present invention can be used in accordance with various wall thicknesses of the drain tube to be obtained, but it is 0.5 mm or more and 6 mm or less from the outer diameter of the mandrel, more preferably 1.0 mm or more and 4.0 mm or less, more preferably It is preferable that the size is 0.5 mm or more and 2.0 mm or less. If the resulting drain tube is thin, the kink resistance is impaired, whereas if it is thick, the flexibility is impaired.

  Silicone raw rubber is used as a raw material for the drain tube of the present invention. This is because the resin has properties suitable for the method for producing a drain tube according to the present invention. Silicone raw rubber containing a small amount of vulcanizing agent can be selected appropriately for the extruder temperature, discharge speed, mandrel passing speed, etc. during extrusion, and also the viscosity of the raw silicone raw rubber can be selected. Can be uniformly coated. In addition, a thermosetting resin having characteristics suitable for the present production method, such as a silicone rubber elastic body can be obtained by heating for a short time of about 1 minute under conditions of 350 ° C. after coating, for example. It is. Further, the drain tube after completion of molding has moderate flexibility and is also a material generally used as a medical material.

  FIG. 4 shows the process of passing two mandrels through the crosshead die. This mandrel is injected with silicone raw rubber from a resin supply device (not shown), receives a coating made of silicone raw rubber (silicone raw rubber shaped in the shape of a drain tube) on the surface, and is discharged from the die. Thereafter, the mandrel cut at the mandrel seam and coated with the raw silicone rubber is sent to a heating furnace and heated and vulcanized to form a silicone rubber elastic body. The mandrel may rotate during coating, or the passage speed of the mandrel may not be constant and the wall thickness may not be constant. Therefore, a mechanism 7 for holding the rear end of the mandrel and moving it at a constant speed as shown in FIG. good.

  The drain tube, which is a silicone rubber elastic body on the mandrel by heat vulcanization, is released from the small holes provided in the groove part of the mandrel by sending compressed air from the joint part of the mandrel. Pulling or removal from the mandrel by compressed air fed to the other end of the mandrel. The drain tube removed from the mandrel is cut into an appropriate length to obtain a product.

  A drain tube having ribs on the inner surface can be obtained by such a manufacturing method. However, when it is desired to use a so-called closed type drainage method or an active drain tube using a pump or the like, the tube manufactured by the above method is used in a predetermined manner. What is necessary is just to attach the connection pipe cut | disconnected to length and shape | molded separately by methods, such as adhesion | attachment and welding. Or the drain tube cut | disconnected by predetermined length may be set to a metal mold | die, and a tube may be connected simultaneously with shaping | molding a connecting pipe by insert molding.

  Furthermore, a side hole may be provided as necessary so that the body fluid can be effectively discharged from the drain tube obtained by the production method of the present invention.

  EXAMPLES Examples relating to the present invention will be described below, but the present invention is not limited to the following examples.

Example 1
In the manufacturing apparatus shown in FIG. 3, a mandrel having a diameter of 10.0 mm, a groove number of 8, a groove depth of 2.0 mm (a V-shape with an angle of 70 °), and a groove parallel to the longitudinal direction of the drain tube, and an opening diameter A silicone raw rubber was coated on the mandrel using a 14 mm die.

  Thereafter, the coated mandrel was cured in a heating furnace at 350 ° C. for 1 minute to form a silicone rubber elastic body, and then the drain tube was removed from the mandrel by sending compressed air to the mandrel, and the entire length was cut to 400 mm.

(Kink resistance test)
In order to examine kink resistance, a ring was formed by holding both ends of the tube, and the diameter at the time when kink was generated by pulling both ends was examined (FIG. 6). As a result, kinks occurred when the diameter of the ring became 50 mm.

(Flow rate test at 90 ° bending)
When the drain tube obtained by the above-mentioned method was bent 90 ° at two locations as shown in FIG. 7 and water was passed through the funnel from above, the flow rate was 470 ml / min.

(Visual surface property evaluation)
The drain tube surface property was evaluated by visual observation, but no sink marks were confirmed.

(Example 2)
A drain tube was formed in the same manner as in Example 1 except that the groove was disposed at an angle of 30 ° with respect to the longitudinal direction of the drain tube.

(Kink resistance test)
In order to examine kink resistance, a ring was formed by holding both ends of the tube, and the diameter at the time when kink was generated by pulling both ends was examined (FIG. 6). As a result, kinks occurred when the diameter of the ring became 60 mm.

(Flow rate test at 90 ° bending)
When the drain tube obtained by the above method was bent 90 ° at two locations as shown in FIG. 7 and water was passed through the funnel from above, the flow rate was 520 ml / min.

(Visual surface property evaluation)
The drain tube surface property was evaluated by visual observation, but no sink marks were confirmed.

(Comparative Example 1)
A drain tube was prepared using a tubular inner die (air was supplied from inside the inner die tube to perform extrusion while keeping the tube circular) and an ordinary extrusion device having an outer die. The outer diameter is 10.0 mm, the number of grooves is 8, the depth of the groove is 2.0 mm (V-shaped at an angle of 70 °), the inner diameter of the tube is parallel to the longitudinal direction of the drain tube, and the diameter of the opening A silicone raw rubber tube was formed using an outer die of 14 mm.

  Thereafter, the silicone raw rubber tube was cured in a heating furnace at 350 ° C. for 1 minute to obtain a silicone rubber elastic body. The total length was cut at 400 mm.

(Kink resistance test)
In order to examine kink resistance, a ring was formed by holding both ends of the tube, and the diameter at the time when kink was generated by pulling both ends was examined (FIG. 6). As a result, kinks occurred when the diameter of the ring became 52 mm.

(Flow rate test at 90 ° bending)
When the drain tube obtained by the above-mentioned method was bent 90 ° at two locations as shown in FIG. 7 and water was passed through the funnel from above, the flow rate was 470 ml / min.

(Visual surface property evaluation)
When the surface properties of the drain tube were evaluated by visual observation, sink marks were confirmed on the outer surfaces at positions corresponding to all the ribs.

(Visual evaluation of rib tip shape)
When the shapes of the rib tips of Examples 1 and 2 and Comparative Example 1 were confirmed, it was confirmed that Examples 1 and 2 were clearly pointed. This is considered to be because the rib was formed using the mandrel.

(Reference example)
A drain tube was prepared using a tubular inner die (air was supplied from inside the inner die tube to perform extrusion while keeping the tube circular) and an ordinary extrusion device having an outer die. A silicone raw rubber tube was formed using an inner die in which a groove having an outer diameter of 10.0 mm was not formed and an outer die having an opening diameter of 14 mm.

  Thereafter, the silicone raw rubber tube was cured in a heating furnace at 350 ° C. for 1 minute to obtain a silicone rubber elastic body. The total length was cut at 400 mm.

(Kink resistance test)
In order to examine kink resistance, a ring was formed by holding both ends of the tube, and the diameter at the time when kink was generated by pulling both ends was examined (FIG. 6). As a result, kinks occurred when the diameter of the ring reached 100 mm.

(Flow rate test at 90 ° bending)
When the drain tube obtained by the above method was bent 90 ° at two locations as shown in FIG. 7 and water was passed through the funnel from above, the flow rate was 310 ml / min.

(Visual surface property evaluation)
The drain tube surface property was evaluated by visual observation, but no sink marks were confirmed.

Side view of mandrel A-A 'sectional view of the mandrel An example of a drain tube manufacturing apparatus using a crosshead die used in the present invention (cross-sectional view) Mandrel coating with a crosshead die The mandrel passing through the crosshead die is passing at a constant speed without rotating. Kink resistance test 90 ° bending flow rate test

Explanation of symbols

A-A 'Mandrel cross-section instruction B One-touch detachable joint C Arc-shaped projection D Small hole drilled in mandrel 1 Extruder 2 Mandrel insertion part 3 Crosshead die body 4 Die 5 Mandrel passage part 6 Silicone raw rubber fluid surface 7 Mechanism to pass the mandrel passing through the crosshead die at a constant speed without rotating.

Claims (6)

In a method of manufacturing a drain tube made of a silicone rubber elastic body having ribs on the inner surface, a cross head die is used to form one or more substantially V-shaped grooves, and a hole penetrating the mandrel is formed. Part of the mandrel, which is a small hole reaching the through hole of the mandrel, is allowed to pass through the inside of the crosshead die substantially parallel to the extrusion line. A method for producing a drain tube, wherein the injection is carried out so as to flow on the outer surface of the mandrel. 2. The drain tube according to claim 1, wherein the substantially V-shaped groove formed in the mandrel is a spiral groove, thereby forming a drain tube made of a silicone rubber elastic body provided with a spiral rib on the inner surface. Production method. The method for producing a drain tube according to claim 2, wherein the spiral groove formed in the mandrel is formed at an angle of 10 ° or more and 80 ° or less with respect to the longitudinal direction of the drain tube. . The method for producing a drain tube according to claim 2, wherein the spiral rib is formed at an angle of 10 ° or more and 80 ° or less with respect to the longitudinal direction of the drain tube. The method for producing a drain tube according to any one of claims 1 to 4, wherein a thickness of a portion of the drain tube where no rib exists is 0.5 mm or more and 2.0 mm or less. One end is provided with a one-touch detachable joint, and the other end is passed through a mandrel with an arc-shaped protrusion that is almost parallel to the extrusion line, and then cut at the mandrel seam. The method for producing a drain tube according to any one of claims 1 to 5, wherein:

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