JP6607819B2 - Circular knitted tubular structure, manufacturing method thereof and manufacturing apparatus thereof - Google Patents

Description

  The present invention relates to a tubular structure formed of a circular knitted fabric and a method for manufacturing the same, and more particularly to a sleeve for covering and protecting a cable such as an electric wire or an optical fiber cable arranged in a vehicle that vibrates when driven by an automobile or the like. The present invention relates to a suitable circular knitted tubular structure, a manufacturing method thereof, and a manufacturing apparatus thereof.

Conventionally, a corrugated tube having a cut in the length direction and an opening that opens and closes in the circumferential direction as shown in Patent Document 1 has been adopted as the protective sleeve as described above. In addition, a protective sleeve formed by braid, warp knitting, or ≡ knitting is known, and a protective sleeve formed by knit knitting as shown in Patent Document 2 below is also known.
In addition, a sound absorbing protective sleeve made of a woven fabric as shown in Patent Document 3 has also been proposed.

JP 2015-37333 A JP 2003-278058 A Special table 2003-506579 gazette

  However, the corrugated tube shown in Patent Document 1 has a certain amount of stretchability and flexibility because it has a bellows shape, but is manufactured from a hard synthetic resin in order to maintain durability. Therefore, the actual situation is that sufficient stretchability and flexibility cannot be obtained. In addition, when used for an object that vibrates like an automobile, the cable housed inside and the inner surface of the corrugated tube collide with each other, generating an audible noise and causing damage to the cable. There is a drawback that the cable must be accommodated in the corrugated tube after covering the cable with a soft cloth or the like in advance or by adhering a cushioning material to the inner surface of the corrugated tube. Further, since the corrugated tube is hard, there is a possibility that an abnormal noise is generated due to a collision between the corrugated tube and a surrounding object on which the corrugated tube is disposed.

  Since the cover for the wiring cord shown in Patent Document 2 uses the cylindrical body itself, the diameter of the cylindrical knitted fabric is determined by the cylinder diameter of the knitting machine. Although it is possible to knit continuously, in order to produce various types of cylindrical knitted fabrics with different diameters, they must be replaced with cylinders with different diameters, and therefore the number of knitting machines according to the type of diameter And a cylinder are required, so that the equipment cost for that is required, and the manufacturing cost is high. Further, since this cover has openings only at both ends of the tubular knitted fabric, the cover cannot be covered on the wiring cord after the wiring cord is connected to the apparatus.

  Furthermore, since the acoustic absorption protection sleeve shown in Patent Document 3 is made of woven fabric, it has a small thickness and is not flexible or stretchable. Therefore, when the sleeve is bent, it can follow the degree of bending. There was a problem that bending occurred and the internal wiring was locally pressed. This sleeve is intended to reduce acoustic vibrations, but has a limited ability to absorb vibrations because it is a thin and inflexible fabric. Furthermore, in order to make this sleeve, it is necessary to weave a very narrow woven fabric, which is difficult in terms of productivity. Therefore, it is conceivable to prepare a wide woven fabric in advance and cut it into a thin tape. However, since the woven fabric is prone to fraying of the warp, the melt-cut portion becomes hard when heat-cutting to prevent fraying. It could not be used because it was easy to damage the wires to be inserted and those that were in contact from the outside.

  The present invention was created in view of the current state of the prior art, and its purpose is that the manufacturing cost is low, the flexibility is high, and the flexibility of bending is high. The present invention provides a circular knitted tubular structure useful as a sleeve for covering and protecting cables such as electric wires and optical fiber cables, a manufacturing method thereof, and a manufacturing apparatus thereof.

As a result of intensive studies by the present inventors, the following a. b. It came to provide the tubular structure excellent in this invention by repeating invention about c.
a. When storing the wiring from the side of the tube, make sure that the tube has an end surface that does not fray and that does not have to be caught.
b. A knitted fabric composition and forming method for forming a knitted fabric cut into a narrow tape into a well-balanced and clean tubular structure.
c. A knitted fabric structure that gives the tubular body shape retention and elasticity.

  That is, for the above-mentioned a, the present inventors have knitted all the yarns constituting the circular knitted fabric in the wale (width) direction, and only the loops are chained in the course direction. Since the yarn is not arranged in a straight line in the (direction), it is difficult to fray when the knitted fabric is cut in the course (length) direction, making the circular knitted fabric the circumference of the desired tubular structure. The width of the tube is adjusted to the width and cut in the course direction with a blade, etc., and the side edge of the tubular structure is not frayed by making the side edge of the sleeve with this cut surface intact. I found.

  Further, the present inventors have made heat shrinkage on the back and front of the knitted fabric (corresponding to the inside and outside of the tubular structure) in order to make the narrow tape-shaped knitted fabric cut in the course direction into a tubular structure. Using a different thread, the thread on the back side was shrunk from the front side thread to devise a tubular structure having a beautiful cylindrical appearance.

  Further, the present inventors maintain a fine tubular structure for the above-mentioned c during the normal time, and have a high-definition yarn on the inner side of the tube in order to have a restoring force against an external impact or compression. Even if this thick fine yarn is left uncut, it is found that the cut portion of the thick fine yarn does not appear on the surface of the knitted fabric, and it is possible to prevent the external contact portion from being damaged or caught. Invented.

  That is, the circular knitted tubular structure according to claim 1 of the present invention is composed of a circular knitted narrow tape whose length is the course direction, and the circular knitted thin tape has a cut edge in the length direction. It is characterized in that it is left and has an overlapping portion in a spiral tube shape in the width direction.

  Further, in the circular knitted tubular structure according to claim 2 of the present invention, in addition to the configuration of the circular knitted tubular structure according to claim 1, the circular knitted narrow tape is provided with a yarn constituting the surface. The high-shrinkage yarn having higher heat-shrinkability than the yarn is composed of a circular knitted fabric disposed on the back surface, and the overlapping portion of the circular knitted thin tape is 1.3 to 2.5 turns of the spiral circumference It is characterized by this. In the present invention, the yarn constituting the surface may include not only a yarn forming a loop but also a yarn exposed on the surface.

  Further, in the circular knitted tubular structure according to claim 3 of the present invention, in addition to the configuration of the circular knitted tubular structure according to claim 1 or 2, the circular knitted fabric is a single knit, and the high shrinkage yarn is It is inserted in the width direction.

  Furthermore, in the circular knitted tubular structure according to claim 4 of the present invention, in addition to the configuration of the circular knitted tubular structure according to claim 1 or 2, the circular knitted fabric is a double knit, and the high shrinkage yarn Is arranged at least in a part of the backside structure.

  In addition to the configuration of the circular knitted tubular structure according to any one of claims 1 to 4, the circular knitted tubular structure according to claim 5 of the present invention is a yarn that forms the surface of the circular knitted fabric. The difference in dry heat shrinkage between the high shrinkage yarn and the high shrinkage yarn is 3 to 80%.

  Furthermore, the circular knitted tubular structure according to claim 6 of the present invention includes a monofilament having a single yarn fineness of 30 to 2400 dtex in addition to the configuration of the circular knitted tubular structure according to any one of claims 1 to 5. The yarn including multifilaments having a single yarn fineness of 30 to 2400 dtex is arranged on the back surface of the circular knitted fabric.

  Furthermore, the circular knitted tubular structure according to claim 7 of the present invention forms the surface of the circular knitted fabric in addition to the structure of the circular knitted tubular structure according to any one of claims 1 to 6. The knit loop is composed of two or more loop lengths, and the ratio of the loop with the shortest loop length to the total loop per unit area is 20 to 75% and the length of the loop with the shortest loop length. The loop length is 20 to 80% of the longest loop length.

  The method for producing a circular knitted tubular structure according to claim 8 of the present invention uses a front yarn and a back yarn having a thermal shrinkage larger than that of the front yarn, and a front loop is formed by the front yarn using a circular knitting machine. Forming and knitting a circular knitted fabric so that the back yarn is arranged on the back side of the front loop, the knitted circular knitted fabric with the course direction as the length direction, with an interval of 1-30 cm in the width direction, Cut in the length direction of the knitted fabric to make a narrow tape, the length of the narrow tape is 0.8 to 1.3 times, and the circular opening is the entrance, spiral shape One end of the narrow tape is passed through a dry heating furnace at 70 to 190 ° C. while passing the narrow tape through a conical forming induction jig having an opening formed in a tapered shape as an outlet. Part is formed in a spiral shape overlapping the other end, and the spiral overlap part is 1.3 to 2.5 rounds of the spiral circumference It is characterized in that it has produced to an.

  An apparatus for producing a circular knitted tubular structure according to claim 9 of the present invention comprises a heating furnace for heating a narrow tape made of circular knitted fabric, and a forming induction jig for molding the narrow tape. The forming guide jig has a conical configuration in which a circular opening portion is an entrance and an opening portion formed in a spiral shape is an exit, and is formed from the entrance to the exit of the forming guide jig. The narrow tape to be drawn is formed in a spiral shape with one end overlapped with the other end, and the spiral shape is fixed by heating with a heating furnace.

  According to the present invention, the narrow tape formed by cutting the circular knitted fabric in the length direction is unlikely to fray at the cut edge of the narrow tape, and thus the circular knitted tubular structure made from the narrow tape. Has the advantage that fraying is less likely to occur. In addition, the tubular structure can be produced from a narrow tape obtained by cutting a circular knitted fabric knitted by a single circular knitting machine regardless of the cylinder diameter into an appropriate width, so that the manufacturing cost is low. Furthermore, the circular knitted fabric itself has elasticity, so that even if it is formed into a circular knitted tubular structure, it has sufficient flexibility and is highly adaptable to bending. Furthermore, the thin tape naturally forms a tubular structure by the heat shrinkage of the high shrinkage yarn having a high heat shrinkage rate, and since the narrow tape is a circular knitted fabric, the opening can be easily opened, and After the cable or the like is housed inside the tubular structure, it does not need to be particularly closed and self-closes due to the shrinking action of the high shrinkage yarn. In addition, since a circular knitted fabric is used, the inner and outer surfaces of the circular knitted tubular structure are soft when configured into a circular knitted tubular structure. Even if the outer surface of the circular knitted tubular structure collides with a surrounding structure or the like, there is an advantage that no abnormal noise is generated. Therefore, it is possible to provide a protective sleeve having a high utility value for covering and protecting a cable such as an electric wire or an optical fiber cable.

  Further, in the manufacturing method of the present invention, a conical shaping induction jig and a heating furnace having a circular opening portion as an inlet and an opening portion formed in a spiral shape as an outlet are used. Can produce a circular knitted tubular structure in which the spiral tubular shape is fixed by passing the narrow tape formed in a spiral shape through a heating furnace. it can.

It is the schematic of the surface of the narrow tape consisting of the circular knitted fabric for producing the circular knitted tubular structure using the single knit which concerns on this invention. It is the schematic of the back surface of the narrow tape consisting of the circular knitted fabric for creating the circular knitted tubular structure using the single knit which concerns on this invention. FIG. 3 is a structure diagram of the single knit shown in FIGS. 1 and 2. It is a fragmentary perspective view of the circular knitted tubular structure using the single knit which concerns on this invention. It is a fragmentary perspective view of the circular knitted tubular structure using the double knit concerning the present invention. It is an organization chart of the double knit concerning the present invention. It is a fragmentary perspective view of the circular knitted tubular structure whose overlap part is less than 1.3 rounds. It is a fragmentary perspective view at the time of bending the circular knitted tubular structure whose overlap part is less than 1.3 rounds. It is a fragmentary perspective view of the circular knitted tubular structure in which an overlapping part exceeds 2.5 rounds. It is a fragmentary perspective view which shows the deformation | transformation state of the circular knitted tubular structure which concerns on the example of manufacture failure. It is a schematic diagram of the manufacturing apparatus for manufacturing the circular knitted tubular structure which concerns on this invention. It is a front perspective view of the shaping guidance jig | tool for manufacturing the circular knitted tubular structure which concerns on this invention. It is the schematic of an accelerator rotor type | system | group friction tester, (a) in a figure is a front view, (b) in a figure is a side view. It is a top view of the whole rubber film. It is a partially expanded front view of a rubber film. It is the photograph which shows the difference of the fray of Example 1 and Comparative Example 1, (a) in a figure shows the case of Example 1, (b) in the figure shows the case of Comparative Example 1. It is a photograph which shows the result of the softness | flexibility evaluation with respect to the bending of Example 1 and Comparative Example 1, the horizontal A row in a figure shows the case of Example 1, and the horizontal B row in a figure shows the case of Comparative Example 1. . 6 is an enlarged photograph showing a difference in change of the tubular structure of Comparative Example 1.

[Single knitted fabric]
The outline of the circular knitted tubular structure of the present invention and the manufacturing method thereof will be described while showing an example of the manufacturing process of the tubular structure using a single knit. The circular knitted fabric is knitted into a cylindrical shape by the circular knitting machine so as to hang downward from the circular knitting machine. Therefore, the vertical direction of the circular knitted fabric coming from the knitting machine is the course direction (length direction) of the circular knitted fabric, and the horizontal direction is the wale direction (width direction). In the present invention, the knitted circular knitted fabric is cut along the course stitches in the course direction of the knitted fabric, and further cut off in the length direction at an appropriate width interval to produce a narrow tape. 1 and 2 show a narrow tape 10 formed from a single circular knitted fabric. The vertical direction in each figure is the length direction of the narrow tape, and the horizontal direction is the width direction. FIG. 3 is a structure diagram of a single knit circular knitted fabric forming the circular knitted tubular structure A.

  As shown in FIG. 3, the single circular knitted fabric has a surface yarn 11 (a total fineness of 167 dtex, a knitted yarn made of 48 filaments of polyethylene terephthalate) forming a knit loop on the surface, and a heat shrinkage rate from the surface yarn 11. Has a large back yarn 12 (high-shrinkage yarn, 670 dtex, polypropylene monofilament inlay yarn), and the front yarn 11 is linked vertically and horizontally to form a knit loop, and the front loop is formed vertically and horizontally. The front thread 11 and the back thread 12 are inserted in the lateral direction (1 tack for 3 welts). FIG. 1 shows the surface of a narrow tape 10 made of a circular knitted fabric (the surface of the circular knitted fabric). FIG. 2 shows the back surface of the narrow tape 10 made of circular knitted fabric (the back surface of the circular knitted fabric), and the back yarn 12 arranged on the back side of the front yarn 11 is partially visible.

  If the narrow tape 10 is heated, the back yarn 12 having a large heat shrinkage rate is thermally shrunk, curved in the direction in which both ends in the width direction of the narrow tape 10 are close, and the side where the back yarn 12 is inserted is the inside. As a cylinder. FIG. 4 shows a state in which the tube is deformed. As shown in FIG. 4, the circular knitted tubular structure A is a state in which one end of the narrow tape 10 is overlapped with the other end to form a spiral shape. In the circular knitted tubular structure A, when the overlapping portion is opened and an electric wire or cable is inserted therein, it is not necessary to manually close the opening of the overlapping portion. The closing function is exhibited, and the opening of the overlapping portion is naturally closed.

[Double circular knitted fabric]
Next, an example of a circular knitted tubular structure using a double knit is shown. The circular knitted tubular structure 1A in FIG. 5 is a tubular structure made of a double knitted circular knitted fabric. FIG. 6 is a structural diagram of a double knit circular knitted fabric forming the circular knitted tubular structure 1A. In FIG. 6, reference numeral 111 denotes a front yarn forming a front loop. That is, the front yarn 111 forms a front loop on the cylinder side by means of knitting. 112a and 112b are back yarns forming a back loop, and the back yarn 112a is a high shrinkage yarn. That is, the back yarn 112a forms a back loop by a tense knitting on the dial side, and the back yarn 112b forms a back loop by a tense knitting on the dial side. In addition to the front yarn 111 and the back yarns 112a and 112b, the double knitted circular knitted fabric includes an engagement yarn 113 that is entangled with the front yarn 111 and the back yarns 112a and 112b and connects the front yarn 111 and the back yarns 112a and 112b. Exists.

  The front yarn 11 described in Example 1 is used as the front yarn 111 and the back yarn 112b. Further, the back yarn 12 described in Example 1 is used as the back yarn 112a. As the engagement yarn 113, a processed yarn of 24 filaments of polyethylene terephthalate having a total fineness of 56 dtex is used. The circular knitted tubular structure 1A is a double knitted circular knitted fabric in which a back loop is formed by the back yarn 112a and the back yarn 112b, and the other description is the same as the circular knitted tubular structure A, and therefore the description thereof. Is omitted.

[Thread constituting the surface]
Next, the composition of the circular knitted fabric constituting the tubular structure of the present invention will be described.

  The yarn that forms a knit loop on the surface of the knitted fabric and constitutes the surface of the knitted fabric (referred to as a surface yarn in the present specification) is not particularly limited as long as it is soft and can give the knitted fabric a covering property. The total fineness of the surface yarn is preferably 30 to 2400 dtex. More preferably, it is 100-1200 dtex. If it is lower than 30 dtex, the covering property tends to be lowered, and if it is 2400 dtex or more, the tubular structure becomes heavy.

  The single yarn fineness of the surface yarn is preferably 0.3 to 20 dtex. More preferably, it is 0.5 to 10 dtex. If it is less than 0.3 dtex, the fibers tend to be caught on the fingers or on the protrusions. If it exceeds 20 dtex, the fiber end part that protrudes from the cut will be tinged when it hits the skin, or the surrounding objects will be easily damaged when rubbed against the surrounding objects.

  The material of the surface yarn is not particularly limited, but synthetic fibers such as polyester, nylon and acrylic, natural fibers such as cotton, hemp and wool, regenerated fibers such as rayon, lyocell, cupra and acetate, semi-synthetic fibers, etc. Any organic fiber may be used. Either long or short fibers may be used. For example, when using a long fiber often used in cable applications, raw yarn may be used, or yarn processing such as false twisting, air entanglement, and covering may be performed. Alternatively, both short fibers and long fibers may be used to form a long / short composite spun yarn using a technique such as core spun yarn or fine spinning / twisting, or a covering yarn in which the spun yarn is coated with long fibers. A polyester multifilament raw yarn or false twisted yarn is preferably used as a relatively inexpensive and durable one.

[High shrinkage thread (back thread)]
For at least a part of the back side of the knitted fabric of the present invention, it is preferable to use a yarn having a high thermal shrinkage rate (hereinafter referred to as a high shrinkage yarn) as compared with the yarn constituting the surface. The shrinkage difference between the front yarn and the high shrinkage yarn on the back surface is more preferably 3-80% of the high shrinkage yarn than the front yarn in the dry heat shrinkage test at 150 ° C. described later. The shrinkage difference may be appropriately selected according to the diameter of the tubular structure to be made. If the tubular structure has a relatively small diameter of 2 to 20 mm, the shrinkage difference of 25 to 80% is set higher. And if it is a tubular structure exceeding 20 mm, it is preferable to set a shrinkage | contraction difference comparatively low.

[Thickness yarn]
In the present invention, it is preferable to use a high-definition yarn in order to give the tubular structure a shape retaining property and a resilience. The thick yarn includes at least a filament having a single yarn fineness of 30 to 2400 dtex. More preferably, it is 300-1200 dtex. The thick fine yarn includes 1 to 5 filaments of the above single yarn fineness. One is preferable. Of course, it may be a single filament monofilament thick yarn. The thick fine yarn may be used on the front surface and / or the back surface.

  Moreover, it is most preferable to use a yarn having both high shrinkage and large fineness as the yarn to be arranged on the back surface. When high-shrinkage and thick yarn is arranged on the back side, when the tubular structure is formed by heating, the end of the cut thick fine yarn shrinks and retracts from the end of the knitted fabric to the back of the knitted fabric Therefore, there is an advantage that the end of the thick yarn is less likely to come into contact with the outside.

[Back yarn material]
The material of the yarn (back yarn) arranged on the back surface is not particularly limited, but synthetic fiber filaments are preferably used. For example, polyethylene terephthalate, polybutylene terephthalate, polyester fibers mainly composed of polytrimethylene terephthalate, polyamide fibers such as nylon 6 and 66, polyolefin fibers such as polyethylene and polypropylene, polyparaphenylene benzoxazole fibers, aramid fibers, poly Arylate fiber or the like is used.

  These fibers may be mixed and used by mixing, twisting, or conjugated yarn. Further, raw yarn (flat yarn) or processed yarn such as false twisting may be used. When used as a yarn having both high shrinkage and large fineness in the present invention, polypropylene fiber or polyester fiber can be preferably used.

[Material ratio]
The ratio of the back yarn high shrinkage yarn to the entire circular knitting is preferably 10 to 80% by weight. If the high shrinkage yarn is in this range, it becomes easy to form a cylindrical shape having a neatly spiral overlapping portion. More preferably, it is 25 to 60% by weight. More preferably, it is 30 to 60% by weight. When the amount is less than 10% by weight, the shape retaining property and elasticity of the tubular structure are lowered, making it difficult to achieve a sufficient protection effect for the cable. When it exceeds 80% by weight, the back yarn high shrinkage yarn becomes too thick and is easily caught.

[Configuration of knitted fabric preferably used]
As the knitted fabric used for the tubular structure of the present invention, a knitted fabric in which yarns are knitted while sequentially forming the knit loop in the lateral direction is used. Such knitted fabrics include circular knitting and flat knitting. When a flat knitted fabric is used, there is an advantage that it is not necessary to open it like a circular knitted fabric, but circular knitting is advantageous in terms of productivity.

  The circular knitting is roughly classified into a single circular knitted fabric and a double circular knitted fabric, and both can be preferably used in the present invention. A single circular knitted fabric is advantageous for forming a thin and thin tubular structure, and a double circular knitted fabric is preferred when it is desired to make a thick and elastic tubular structure.

[Thickness of fabric (raw machine), basis weight]
When a single circular knitted fabric is used for the knitted fabric of the present invention, the thickness of the knitted fabric is preferably 0.3 to 1.0 mm. If the thickness is less than 0.3 mm, the shape retaining property of the tubular structure tends to deteriorate. On the other hand, when the thickness exceeds 1.0 mm, the tubular structure is difficult to twist when the tubular structure is mounted, so that the workability is likely to deteriorate. The basis weight of the single circular knitted fabric is preferably 70 to 230 g / m ² . If the basis weight is less than 70 g / m ^{2, the} shape retaining property tends to deteriorate. When the weight per unit area exceeds 230 g / m ² , the weight of the tubular structure becomes heavy, which may be disadvantageous in a field that requires light weight, such as a car application.

When a double circular knitted fabric is used for the knitted fabric of the present invention, the thickness of the knitted fabric is preferably 0.5 to 1.5 mm. When the thickness is lower than 0.5 mm, the shape retention of the tubular structure tends to be deteriorated. On the other hand, if the thickness exceeds 1.5 mm, when the tubular structure is mounted, it becomes difficult to twist the tubular structure, so that workability tends to deteriorate. The basis weight of the double circular knitted fabric is preferably 100 to 370 g / m ² . If the basis weight is less than 100 g / m ^{2, the} shape retaining property tends to deteriorate. When the weight per unit area exceeds 370 g / m ² , the weight of the tubular structure becomes heavy, which may be disadvantageous in a field that requires light weight, such as a car application.

[Overlap]
In the present embodiment, the narrow tape 10 is rounded so as to form an overlap portion of 1.3 to 2.5 rounds when one end thereof is overlapped with the other end to form a spiral. A knitted tubular structure A is created. As shown in FIG. 7, in the case of a circular knitted tubular structure B having an overlap portion of less than 1.3 turns, as shown in FIG. When bent, the overlapping portion is opened and the internal electric wires, cables, and the like are exposed from the circular knitted tubular structure B, which is not appropriate. In addition, as shown in FIG. 9, if the overlapping portion is a circular knitted tubular structure C having more than 2.5 rounds, it becomes difficult to insert an electric wire or a cable into the circular knitted tubular structure C. Absent.

[Tubular structure diameter, basis weight]
The tubular structure made of the circular knitted fabric of the present invention can be applied with a diameter of 2 to 50 mm. If the diameter is less than 2 mm, it becomes difficult to form a spiral tubular structure, and if the diameter exceeds 50 mm, the shape retaining property tends to deteriorate. This is because when the diameter is increased, the cable to be embedded is also heavier and heavier, making it difficult to obtain the protective effect required by the heavy cable.

  A preferred weight per meter in consideration of the diameter of the tubular structure is represented by basis weight (g / m) / diameter (mm). In the case of a single circular knitted fabric, this value is preferably 0.6 to 1.5. In the case of a double circular knitting, it is preferably 1.2 to 3.0. If the tubular structure is less than the lower limit of these ranges, shape retention tends to be reduced, and if it exceeds the upper limit, it may become too heavy.

[Narrow tape]
The narrow tape of the present invention can be produced by cutting a circular knitted fabric in the length direction at intervals of 1 to 50 cm in the width direction. A preferred width of the narrow tape is 2 to 30 cm. If it is less than 1 cm, it becomes difficult to form a beautiful tubular structure. If it is 50 cm or more, the shape retaining property of the tubular structure formed tends to deteriorate. Any method can be used to cut the circular knitted fabric in the length direction as long as the cut surface does not harden or become easily caught. For example, use a blade such as a scissors or a knife. Or can be cut using ultrasonic waves, air current, water flow, or the like. The side surface of the narrow tape of the present invention is used for use at the edge that has been cut by the method as described above. Thereby, the manufacturing process of a tubular structure can be simplified and it can manufacture efficiently and cheaply. In the present invention, the state of being cut without performing the fraying prevention process is referred to as “keep cutting”.

  In addition, before cutting the opened circular knitted fabric into a tape shape, it is also preferable to perform a primary heat treatment at a low temperature of, for example, less than 150 ° C. to shape the flat knitted fabric without curling at no load. This low-temperature heat treatment is for improving workability when cutting into a narrow tape in the next step, and is not always necessary, but is an effective method particularly in the case of a single circular knitted fabric. That is, when the circular knitted fabric is opened, the circular knitted fabric is easily curled or skewed. By doing so, there is an advantage that the circular knitted fabric can be easily and neatly cut to easily produce a narrow tape.

[Molding method]
When the knitted fabric of the present invention is heated, a difference in shrinkage between the front surface and the back surface occurs, and the narrow tape can be formed into a spiral tubular structure. The heating method is dry heat heating using convection of heated air with a hot air dryer, etc., wet heat heating using a steamer, etc., contact heating with high temperature metal or heat medium, wet infrared radiation, electromagnetic wave heating such as microwaves Anything that can be used for heating the fibers such as can be used, or they may be used in combination. A method using a hot air dryer or contact heating is preferable.

  For example, when using a hot air dryer, the running temperature of the dryer may be set to 50 to 210 ° C. Preferably it is 70-190 degreeC. Since the narrow tape can be elongated in the length direction, an apparatus that can be continuously processed by providing an inlet and an outlet in the heating facility is preferably used in terms of productivity improvement.

  Note that the width of the narrow tape also shrinks due to heating. In other words, the width of the narrow tape that is obtained by unfolding the spiral tubular structure after heating is flatter than the width of the narrow tape before heating, and the width of the narrow tape after heating is the same as that before heating. Is about two-thirds of the width.

[Swirl-shaped induction]
As described above, when the knitted fabric of the present invention is heated, a difference in shrinkage between the front surface and the back surface occurs, and the narrow tape can be formed into a spiral tubular structure. However, for example, during the production of the circular knitted tubular structure A, both ends in the width direction of the narrow tape are close to each other and inward with the both ends abutted as in the circular knitted tubular structure A ′ shown in FIG. May form a curved double mountain. In this case, it is also possible to operate one end part to be above the other end part to make a spiral, but the bending force is weaker than expected and the self-closing function Tends to decrease or the formation of overlapping portions tends to be insufficient. Therefore, in the manufacturing method of the present invention, as will be described later, using a conical forming induction jig having a circular opening portion as an inlet and an opening portion tapered in a spiral shape as an outlet, It is preferable to manufacture the circular knitted fabric so as to be forced into a spiral shape.

  FIG. 11 is a schematic view showing an example of a manufacturing apparatus for a circular knitted tubular structure, and the manufacturing apparatus D for the circular knitted tubular structure has a heating furnace 30 for heating the narrow tape 10 made of circular knitted fabric. And a shaping guide jig 20 for shaping the narrow tape 10 in a spiral shape. The narrow induction tape 20 shapes the narrow tape 10 in a spiral shape with one end overlapped with the other end, and when the narrow tape 10 passes through the formation induction jig 20, the heating furnace 30. The spiral yarn of the circular knitted tubular structure A shaped into the spiral shape is maintained by the heat shrinkage of the back yarn of the high shrinkage yarn that is heated by the thin tape 10 and is arranged on the narrow tape 10, and the spiral shape is maintained. The circular knitted tubular structures A and 1A shown in FIGS. 4 and 5 maintaining the form are completed.

  As shown in FIG. 12, the shaping guide jig 20 is formed by winding a flat plate into a conical shape, and the opening on the entrance side where the narrow tape 10 is inserted has a narrow tape 10. Is a flat opening portion 21 having a large diameter, and the opening portion on the outlet side is an opening portion 22 formed in a spiral shape because the narrow tape 10 is deformed in a spiral shape. Is. Then, in the opening portion 21 on the inlet side of the forming guide jig 20, the front side of the narrow tape 10 becomes the spiral inner peripheral surface side, and a part of the narrow tape 10 is spiral in the opening portion 21. The flat narrow tape 10 is forced to overlap one end with the other end by inserting it so as to be sandwiched between the overlapping portions and pulling it out from the tapered spiral opening 22 on the outlet side. Shaped into a spiral. Note that the circular shape of the opening 21 on the inlet side is not limited to a perfect circle, and includes an ellipse.

[Molding condition]
Next, an example of specific molding conditions using the manufacturing apparatus will be shown. While passing the shaping guide jig 20 shown in FIG. 12 in the range where the narrow tape is 0.8 to 1.3 times longer in the length direction, the narrow tape 10 The heat-shrinkable yarn is heat-shrinked by heat-treating the narrow tape 10 at a temperature of 70 to 190 ° C., and one end of the narrow tape 10 is overlapped with the other end to be bent in a spiral shape. A circular knitted tubular structure A in which 1.3 to 2.5 overlaps are formed is manufactured. Note that the range in which the narrow tape 10 is 0.8 to 1.3 times longer means that the narrow tape 10 is passed through the shaping guide jig 20 when the narrow tape 10 is passed through the shaping guide jig 20. It is a range of numerical values when the thin tape 10 is pulled out from the shaping guide jig 20 and expanded from the numerical values when the narrow tape 10 is contracted by being pushed into the tape.

  Next, the present invention will be specifically described using Examples and Comparative Examples, but the present invention is not limited to these. The measuring method of each characteristic value used in the present invention is as follows.

<Total fineness dtex of yarn>
Measured by JIS L1013 8.3.1 Positive Fineness.

<Number of filaments>
JIS L1013 8.5.1 Measured by the number of filaments.

<Single yarn fineness dtex>
The fineness (single yarn fineness) of the monofilament in the yarn is determined from the total fineness and the number of filaments.
Single yarn fineness dtex = total fineness / number of filaments

<Yarn dry heat shrinkage%>
A load of 1/27 g / dtex is applied to the sample, and its length L1 (mm) is measured. The load is then removed and the sample is placed in a dryer and dried at 160 ° C. for 30 minutes. After drying, it is cooled at room temperature, a load of 1/30 g / dtex is applied again, and its length L2 (mm) is measured. Substituting the above L1 and L2 into the following equation, the 160 ° C. dry heat shrinkage rate is calculated. In addition, let the average value of the measurement frequency | count of 5 times be the measured value.
Dry heat shrinkage% = [(L1-L2) / L1] × 100

<Density density / 2.54cm>
It is measured by the density of the knitted fabric based on JIS L1096 8.6.2.

<Thickness>
The thickness was measured by the thickness based on JIS L1096 8.4B method.

<Weaving weight g / m ² , Tubular structure weight g / m>
The fabric basis weight was measured by mass per unit area based on JIS L1096 8.3B method. The mass per unit length of the tubular structure was measured by measuring the mass of the tubular structure 1 m in length.

<Ease of fraying the cutting edge of the tubular structure>
The ease of fraying of the cutting edge (the side of the tubular structure) in the longitudinal direction of the tubular structure is measured using the JIS L1096 8.19.4 D method (accelerator type method), which is a method for measuring wear strength. . The tubular structure was cut to a length of 10 cm in length and the cut edge was secured by gluing the entire edge, leaving 5 mm from the cut edge in the length direction so that it would not fray during the test. . At this time, an adhesive is not attached to the cutting edge (side of the tubular structure) for measuring the ease of fraying. Next, an iron was applied at a temperature at which the fiber material constituting the tubular structure did not melt, and the spiral structure was extended to flatten the tubular structure to prepare a measurement sample.

FIG. 13 shows an accelerator rotor type wear tester E for confirming the ease of fraying. In the figure, a represents a metal rotating blade, b represents a cylinder, c represents a rubber film, d represents a glass plate, and e represents a lid. Usually, abrasive paper is affixed to the inner peripheral surface of the cylinder b in the testing machine E, but in this testing machine, an uneven rubber film c shown in FIGS. 15 and 16 was used instead of the abrasive paper. . The rubber film c has the same length as the inner circumference length of 43.5 cm of the cylinder b, the same width as the depth of the cylinder of 7.0 cm, and a thickness of 0.35 cm (the step height h of the uneven portion is 0.2 cm). It is a rubber material having a hardness of 82 to 83A and a mass of 125 g to ± 1 g. In the testing machine E, the measurement sample is sandwiched under the rotating blade a, the rotating blade a is rotated at a rotation speed of 2000 times / minute for 2 minutes, and the measurement sample is floated and rotated in the cylinder, and then the measurement sample is measured. Is removed from the cylinder and the number of yarns that have frayed from the longitudinal cutting edge is counted. At this time, the yarns that fray more than half the length of the cut edge of the measurement sample are counted as the number of frayed yarns. Evaluation is rejected if there is even one frayed yarn.
<Bendability of tubular structure>
When the tubular structure was rolled into a circular shape and connected to both ends, the bendability of the tubular structure was evaluated based on whether or not an angular bend was generated on the inner periphery of the ring. Even if it is a small circular shape, it is a tubular structure that is excellent in bendability so that bending does not occur.

(1) The tubular structure for evaluation is cut to a target inner circumferential length + sewing allowance of 10 mm.
The evaluation ring had a diameter mm (circumferential length mm) of the following six types. The diameter and circumferential length are based on the inner diameter of the ring.
100 (314), 75 (236), 50 (53), 30 (94), 15 (47), 10 (31)

  (2) Next, how to make a sample will be described in detail. For example, when making a ring with an inner diameter of 100 mm, the tubular structure is cut to 314 mm + sewing allowance length 10 mm = 324 mm. Overlay the seam allowance part so that the inner diameter circle does not become distorted at the seam allowance part, and align the seam allowance part along the center of the tubular structure in accordance with the circumference at the main stitch with a pitch of 1 mm. An evaluation sample was prepared by sewing together with a sewing machine.

(3) The evaluation sample was allowed to stand on a horizontal desk and visually judged from directly above according to the following criteria.
The evaluation criteria are as follows. Evaluation criteria 5 to 3 were acceptable, and evaluation criteria 2 and 1 were unacceptable.
5: An almost perfect circle, showing no wrinkles or folds.
4: An almost perfect circle is shown, but wrinkles at one or more inner peripheral surfaces of the circle are observed.
3: Many wrinkles are recognized on the inner peripheral surface of the circle.
2: The circular shape is broken, and several folds are observed on the inner peripheral surface.
1: Many square folds of V-shape are generated and deformed into a polygonal shape.

  Using a single circular knitting machine (VX-JS3 type, diameter 30 inch, needle density 22G) manufactured by Fukuhara Seisakusho, a 167 dtex-48 filament polyethylene terephthalate 2-heater false twisted yarn (dry heat shrinkage 3%) as the front yarn Used as the insertion thread on the back side, 670 dtex polypropylene monofilament (thickness / high shrinkage thread) with a dry heat shrinkage rate of 30% is inserted at the ratio of the structure shown in FIG. And knitted. The resulting knitted fabric had a density of 50 / 2.54 cm course, 44 / 2.54 cm wales, a thickness of 0.60 mm, and a basis weight of 140 g / m 2. The material mixing ratio was 67% for polyethylene terephthalate and 33% for polypropylene.

  After the knitted fabric was opened, it was cut into a slit shape in the length direction with a scissors to prepare a narrow tape having a width of 8 cm. The width of the narrow tape shrinks and the insertion thread on the back surface shrinks by subjecting this narrow tape to heat molding treatment at a set temperature of 170 ° C. for 2 minutes in a hot air dryer while using the molding induction jig described above. Thus, a tubular structure having a diameter of 1 cm and an overlap portion of 1.7 was produced.

  Using a double circular knitting machine (V-LPJ4 type, diameter 30 inch, needle density 20G) manufactured by Fukuhara Seisakusho, 167 dtex- having a dry heat shrinkage rate of 3% as in Example 1 as the front yarn on the cylinder side of the knitting machine A 48-filament false twisted yarn is alternately knitted with 220 dtex polypropylene monofilament with a dry heat shrinkage of 30% as the back yarn on the dial side of the knitting machine and the same 167 dtex false twisted yarn as the front yarn. The interlock knitting shown in the organization chart of FIG. 6 was knitted. The density of the resulting knitted fabric was 48 / inch course, 26 / inch wale, the thickness of the knitted fabric was 1.2 mm, and the basis weight was 250 g / m 2. This knitted fabric was cut in the same manner as in Example 1 to obtain a narrow tape having a width of 8 cm. This narrow tape was 70% polyethylene terephthalate and 30% polypropylene.

  By using the above-mentioned forming induction jig, the narrow tape is heat-molded in a hot air dryer at a set temperature of 170 ° C. for 2 minutes, whereby the width of the narrow tape is contracted, and the back thread is contracted, A tubular structure having a diameter of 1 cm and an overlapped portion of 1.7 was produced.

Comparative Example 1

  As Comparative Example 1, a tubular structure manufactured from a woven fabric is illustrated.

  As the warp, a 167 dtex 48 filament polyethylene terephthalate fiber 1 heater false twist yarn (dry heat shrinkage 3%, black original yarn) was warped and used. A 660 dtex polypropylene monofilament (black original yarn) having a dry heat shrinkage of 30% was used as the weft. Using these warps and wefts, weaving fabrics with a rapier loom made by Ishikawa Seisakusho with a 3/1 right twill structure with a raw machine density of 38 warps / 2.5 cm, 25 wefts / 2.5 cm, and a weaving width of 100 cm. did. This woven fabric was heat cut along the warp of the woven fabric using a flat type soldering iron and applied with a ruler to form a narrow tape having a width of 8 cm in which both sides were frayed by heat cut.

  This narrow tape was heat-treated using the above-described forming guide jig under the same operation and processing conditions to obtain a tubular structure. The resulting tubular structure had a diameter of 1 cm and an overlap portion of 1.7.

  In the single circular knitted fabric (Example 1) and the double circular knitted fabric (Example 2) configured as described above, the circular knitted fabric itself is stretchable, and the resulting tubular structure has sufficient flexibility, so that the woven tubular Compared to the structure, it is very adaptable to bending. Further, as shown in FIG. 16, the side cut portion of the tubular structure in Example 1 ((a) in the figure) is also used in the friction test based on the above-mentioned <ease of fraying of the cutting edge of the tubular structure>. There was no fraying at all. On the other hand, the end face of the heat cut woven fabric seen in Comparative Example 1 ((b) in the figure) is hard and feels caught by the hand, and in the friction test, as shown in FIG. 16, strong fraying occurs. It was.

  Next, with respect to each tubular structure of Example 1 and Comparative Example 1, the results of the flexibility evaluation with respect to bending are shown in Table 1, FIG. 17 and FIG. Among the comparative example circular evaluation bodies, the inner diameters of 15 mm and 10 mm were excluded from the evaluation targets because they were already 30 mm evaluation bodies and angular.

  FIG. 17 shows the horizontal A row showing the case of Example 1 with an inner diameter of 100 mm (A1 in the figure), 75 mm (A2 in the figure), 50 mm (A3 in the figure), 30 mm (A4 in the figure). , 15 mm (A5 in the figure), 10 mm (A6 in the figure) is a photograph showing the change of the shape when changed in six stages, for the horizontal B row showing the case of Comparative Example 1, the inner diameter is 100 mm (B1 in the figure), 75 mm (B2 in the figure), 50 mm (B3 in the figure), and 30 mm (B4 in the figure). FIG. 18 is an enlarged photograph of the inner diameter of 75 mm and 50 mm in Comparative Example 1 in FIG. 17 and shows that the tubular structure changes significantly. In Comparative Example 1, the inner diameter is 75 mm ( In the case of B2) in the figure, many wrinkles are recognized on the inner circumferential surface of the circle as indicated by an arrow, and in the case of 50 mm (B3 in the figure), on the inner circumferential surface as indicated by an arrow. Several wrinkles and folds are recognized, and the circle is broken.

A ... Round tubular structure 10 with single circular knitted fabric ... Narrow tape 11 ... Front yarn 12 forming front loop ... Back yarn B with large thermal shrinkage ... Comparison Circular knitted tubular structure C of Example 1... Circular knitted tubular structure 1A of Comparative Example 2... Circular knitted tubular structure 111 by double circular knitted fabric .. Front yarn 112a forming back loop. A back yarn 112b having a large thermal shrinkage rate, a back yarn 113 forming a back loop, an engagement yarn A ′, a double circular circular knitted tubular structure 20, a shaping guide jig 21,・ Flat opening portion 22... Spiral opening portion D... Manufacturing device 30 for circular knitted tubular structure... Heating furnace E... Accelerator rotor type abrasion tester a. Rotating blade b ... Cylinder c ... Rubber film d ... Glass plate e ... Lid

Claims (9)

  It consists of a circular knitted thin tape with the course direction as the length direction, and the circular knitted thin tape has a cut edge in the length direction and a spiral tube shape in the width direction. A circular knitted tubular structure characterized by having an overlapping portion.   The circular knitted narrow tape is composed of a circular knitted fabric in which a yarn constituting the surface is arranged, and a high shrink yarn having higher heat shrinkage than the yarn is arranged on the back surface, and the overlapping portion of the circular knitted narrow tape The circular knitted tubular structure according to claim 1, wherein is a spiral circumference of 1.3 to 2.5 rounds.   The circular knitted tubular structure according to claim 1 or 2, wherein the circular knitted fabric is a single knit, and the high shrinkage yarn is inserted in a width direction.   The circular knitted tubular structure according to claim 1 or 2, wherein the circular knitted fabric is a double knit, and the high shrinkage yarn is arranged at least in a part of the back surface structure.   The circular knitted tubular according to any one of claims 1 to 4, wherein a difference in dry heat shrinkage between the yarn constituting the surface of the circular knitted fabric and the high shrinkage yarn is 3 to 80%. Structure.   The yarn containing monofilaments having a single yarn fineness of 30 to 2400 dtex and / or multifilaments having a single yarn fineness of 30 to 2400 dtex is arranged on the back surface of the circular knitted fabric. The circular knitted tubular structure described in 1.   The knit loop constituting the surface of the circular knitted fabric is composed of two or more loop lengths, and the ratio of the loop having the shortest loop length to the total loop per unit area is 20 to 75%, and the loop The circular knitted tubular structure according to any one of claims 1 to 6, wherein the length of the loop having the shortest length is 20 to 80% of the length of the loop having the longest loop length. A circular knitted fabric that uses a front yarn and a back yarn having a larger thermal shrinkage than the front yarn and forms a front loop with the front yarn by a circular knitting machine so that the back yarn is arranged on the back side of the front loop. Organize
The knitted circular knitted fabric is cut in the length direction of the knitted fabric with an interval of 1-30 cm in the width direction, with the course direction as the length direction, to create a narrow tape,
A conical forming guide in which the length of the narrow tape is 0.8 to 1.3 times, the circular opening is the inlet, and the spirally tapered opening is the outlet. While passing the narrow tape through the jig, it is passed through a dry heating furnace at 70 to 190 ° C. to form a spiral tape with one end of the narrow tape superimposed on the other end, and the spiral A circular knitted tubular structure manufacturing method characterized in that the circular overlapping portion is manufactured so as to be 1.3 to 2.5 rounds of a spiral circumference.   A heating furnace for heating a narrow tape made of circular knitted fabric and a forming induction jig for forming the narrow tape, and the forming induction jig has a circular opening portion as an entrance, and a spiral A conical structure having an opening formed in a tapered shape as an outlet, and a narrow tape drawn from the inlet of the forming guide jig to the outlet is overlapped with one end on the other end An apparatus for producing a circular knitted tubular structure, characterized in that it is formed in a spiral shape and the spiral shape is fixed by heating with a heating furnace.