JPH01241507A - Manufacture of spacer for carrying optical fiber with colored part for identification - Google Patents

Abstract

PURPOSE:To eliminate peeling in use and to improve the hardness of coloring by putting a wire element for identification together at the tip part of a rotary die and coating it integrally at the time of the extrusion coating of a tensile strength wire. CONSTITUTION:The resin of the spacer 3 is obtained by converging a resin flow A in a cross head die 2 from a cylindrical shape to a conic shape and putting it together with a coloring resin flow B supplied from another extruder at a die lip part which has a projection corresponding to the shape of the spacer 3. Namely, while the die lip is rotated, the outer periphery of the tensile strength wire is coated and the take-up speed and the rotating speed of the die lip are selected properly to obtain the spacer 3 with specific spiral pitch. Consequently, the spacer 3 which has the wire element for identification free from uncoloring is obtained without coloring by ink printing, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing an optical fiber supporting spacer used as a component of an optical fiber, which is colored for identification.

(Prior art and problem to be solved by the invention) When making an optical fiber into a cable as a communication line, the optical fiber is housed in the groove of a spacer having multiple spiral grooves on the outer periphery, and the optical fiber is connected to the cable. It is common practice to do so.

The above-mentioned optical fiber supporting spacer usually has a tensile strength wire as a core material, a thermoplastic resin layer is provided on the outer periphery of the core material, and a plurality of spiral grooves are formed on the outer peripheral surface of the core material at a predetermined spiral pitch. The number of grooves varies depending on the capacity of the cable, but is generally set to 4 to 12.

With the above spacer, when storing an optical fiber in a spiral groove when making a cable, or when actually laying an optical fiber cable, when connecting cables to each other or branching optical fibers, the groove of the spacer is used. It is necessary to identify the target optical fiber stored in the target optical fiber.

However, as described above, there are a plurality of grooves, and their shapes are often the same, and moreover, they are formed in a spiral shape at a predetermined pitch, making it difficult to identify the target groove or optical fiber.

To facilitate this identification, for example, methods such as coating the outer periphery of the optical fiber with synthetic resin coatings of different colors, or inserting identification paper into the spiral groove are adopted. However, with the former method, there is a limit to the number of colors of coloring pigments that can be mixed into the synthetic resin, while with the latter method, there are problems such as the addition of an intervening paper insertion step.

As methods to solve these problems, methods have been proposed such as providing grooves or protrusions on the ribs of the spacer, and applying ink to these grooves. When it is necessary to wipe the exposed area with a petroleum-based solvent, the ink may be eluted, which is undesirable for work.

From this point of view, there has been a demand for an optical fiber supporting spacer having identification stripes that do not fade in color.

The present invention has been made in view of the above-mentioned background, and provides a novel method for manufacturing a spacer for supporting an optical fiber, which has identification stripes that do not fade, instead of using a coloring method such as printing with ink. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a light beam in which a tensile strength line is arranged in the center and a spacer body having a plurality of spiral grooves is coated on the outer periphery of the tensile strength line with a thermoplastic resin. In the method for manufacturing a fiber-supporting spacer, <the tensile strength wire is inserted into a crosshead die, and a thermoplastic resin for the spacer body and a colored resin for identification are merged on the outer periphery at the tip of the crosshead die. , the tip is coated while being rotated.

The tensile strength wire that can be used in the manufacturing method of the present invention is a single wire or stranded metal wire such as steel wire, a single wire or stranded wire of fiber-reinforced plastic wire, or a single wire or stranded wire that is coated with an adhesive thermoplastic resin or a thermoplastic resin. A polyoxymethylene rod or a thermotropic liquid crystal rod may also be used.

Since these tensile strength wires need to be mutually bonded to the thermoplastic resin that forms the main body of the spacer coated on their outer periphery, single-wire tensile strength wires require surface treatment to improve adhesion. For example, coating with adhesive resin as mentioned above is desirable, but when using stranded wires, the surface has irregularities due to twisting, and if the outer periphery of this wire is coated with thermoplastic resin, the shear bond strength in the longitudinal direction will increase due to the anchor effect. Since it can be improved, coating with adhesive resin is not necessarily required.

The resin for the spacer body is appropriately selected from various thermoplastic resins depending on the performance required for the spacer, but high-density polyethylene (HDPE) is selected from various physical properties such as low temperature resistance and economic efficiency. It is.

On the other hand, the colored resin used is one obtained by kneading a colored pigment into a resin that is compatible with and can be fused to the resin for the spacer body.

In order to merge the spacer body resin and the colored resin at the die tip, the spacer resin converges the resin flow from a cylindrical shape to a conical shape in a crosshead die, and a die lip with a protrusion corresponding to the shape of the spacer is used. If the die lip is rotated to cover the outer periphery of the tensile strength line, and the take-up speed and the number of rotations of the die lip are appropriately selected, A spacer with a predetermined helical pitch can be obtained.

The joining position of the resin for the spacer body and the colored resin is determined according to the colored striations for identification of the target spacer, and when applying colored striations of multiple colors to the spacer, the number of colored striations corresponding to the number of colors is determined. The colored resin may be supplied from an extruder and allowed to merge.

(Example) The present invention will be explained below with reference to Examples.

Example 1 A single steel wire with an outer diameter of 2.3 mm was extruded and coated with ethylene-ethyl acrylate copolymer (manufactured by Nippon Unicar: trade name GA004), and then passed through a heated shaping die with an inner diameter of 4.0 mm. A coated tensile strength wire with a diameter of 4.0 mm was obtained.

After preheating this coated tensile strength wire 1 to 180°C, high-density polyethylene (Ml-0,
3) As colored resin B, black color pellets made of high-density polyethylene as a base and black pigment mixed therein were supplied from separate extruders (not shown), and both resins were configured to merge at the tip of the die. After passing through the crosshead die 2 and coating the die lip while rotating, the rib 20 is coated with the cross-sectional shape shown in FIG. 3 through a cooling and solidifying process.
．． 5+am, the bottom diameter of the groove 21 was 4.9 mm, the spacer 3 had a colored portion 22 for identification, and had a helical pitch of 500 in the Z twist direction.

The crosshead die 2 includes a stationary die 201 formed in a substantially convex shape, a hollow cylindrical die rotation block 202 rotatably fitted to the outer periphery of the convex portion of the stationary die 201, and a die rotation block. The fixed block 204 is arranged on the outer periphery of the die 202 via a heat-resistant bearing 203.
It is fixed at 04.

On the central axis of the stationary die 201, there is a tensile strength line 1 on the tip side.
A tapered nipple 20 having a guide hole 205a and a reduced diameter portion 205b protruding from the tip surface of the stationary die 201.
5 is attached, and a guide 206 that guides the tensile strength wire 1 toward the guide hole 205a is fitted to the rear end of the nipple 205.

The die rotation block 202 includes a cylindrical main body 202a, a flange 202b fixedly provided at the rear of the main body 202a and having a gear carved therein, and a die lip with a concave cross section fixedly provided at the front of the main body 202a. It is composed of an adapter 2020, a die lip 202d fitted into a recessed part of the die lip adapter 202c, and a disk-shaped cover 202e attached to the front surface of the die lip 202d.

Inside the stationary die 201, a first supply path 207 for main body resin A and a second supply path 208 for colored resin B are formed separately. A cylindrical flow path 207a and a reduced diameter portion 205b of the nipple 205 are formed along the flow path 207a.
and the die lip 202d.
07b.

On the other hand, the second supply path 208 is located outside the cylindrical flow path 207a, and an opening at the tip end surface of the stationary die 201 communicates with an annular flow path 209 recessed in the side surface of the die lip adapter 202C. are doing.

The annular flow path 209 is provided with a through flow path 2 that penetrates in the axial direction of the die lip adapter 2020 at a predetermined position.
21 is provided, and the through flow path 221 is connected to the die lip 202.
A portion of the die lip 202d that communicates with the L-shaped channel 210 provided at the die lip 202d and is exposed at the tip surface of the die lip 202d is covered with a cover 202e.

Further, a drive gear 212 for rotating the flange portion 202b of the die rotation block 202 is engaged with the flange portion 202b.

Furthermore, a through hole 213 having a shape corresponding to the cross-sectional shape of the spacer 3 to be obtained is formed in the die portion consisting of the die lip 202d and the cover 202e, and the tip of the cross-shaped channel 210 is connected to the rib 20 of the spacer 3. A protrusion 214 that removes the outer circumference of the rib 20 in a substantially V-shape is provided on the inner circumferential surface of the through-hole 213 of the mouthpiece, behind the opening of the flow path 21Q.

When the molten main resin A1 and the colored resin B are extruded and supplied to the first and second supply channels 207 and 208 of the crosshead die 2 configured as described above, the main resin A flows from the conical channel 207b to the nipple 205. It is extruded to the outer periphery of the tensile strength line 1 that protrudes from the tip.

At this time, a part of the extruded main body resin A is blocked by the protrusion 214 of the die lip 202d in a figure 7 shape,
The colored resin B from the L-shaped flow path 210 fills the blocked area and merges with the main body resin A, and the cover 2
02e and is coated in a predetermined shape.

The above-mentioned coating of the tensile strength wire 1 with the main body resin AS colored resin B is carried out while rotating the adapter 202C and the die rotation block 202 connected to the mouthpiece made up of the die lip 202d and the cover 202e using the drive gear 212. The spacer 3 having the configuration as described above is
is obtained.

In addition, in this embodiment, one rib 20 of the spiral spacer 3 is colored in black in the form of a single line, but other ribs 20 are colored in the same color.
It is also possible to provide a plurality of identification lines by inserting a plurality of colored filaments into the rib, or by making the width of the colored filament the full width of the rib width or by making it thinner.

For example, as shown in FIG. 5, when inserting identification lines into two ribs, the L-shaped channel 210 shown in FIG.
All you need to do is set up one place. (See Figure 4) When applying different color identification lines, the supplied resins of different colors are guided to separate resin supply grooves, and introduced from the supply grooves into resin flow paths for each color. It is sufficient to merge it with the main resin for the spacer body at the tip of the die.

The position where the colored filaments are inserted is not limited to the top of the rib, but may be the bottom or side of the groove.

Further, in this embodiment, a unidirectional spiral spacer has been described, but it goes without saying that the present invention can also be applied to a spacer having grooves that are alternately reversed as appropriate.

Further, in the embodiment, the case where the product is taken in the horizontal direction has been described, but this can also be changed to the vertical direction.

(Effect) In the present invention, the identification filament of the helical spacer is integrally coated with the main resin part of the spacer body because it is integrally coated by merging it at the tip of the rotating die when extrusion coating the tensile strength wire. It is fused to the striated portion, so it does not peel off during use, and the color fastness is high.

Therefore, with conventional products that were colored with ink in the post-process, problems such as color fading occurred when wiping with petroleum-based solvents to remove jelly compounds and the like during optical cable connection work. Or maybe there is no such concern.

As described above, the method for manufacturing a fiber-supporting spacer according to the present invention is novel and extremely useful.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the die head used in the embodiment of the present invention, Fig. 2 is an explanatory diagram of the die lip of Fig. 1, and Fig. 3 is a spacer having a colored part for identification obtained by the method of the present invention. 4 is an explanatory view showing a modification of the die lip, and FIG. 5 is a sectional view of a spacer obtained with the die lip of FIG. 4. 1... Tensile strength wire (covering) 2... Crosshead die 3... Spacer 20... Rib 21
... Groove 22.23 ... Colored part for identification Patent applicant: Ube Nitto Kasei Co., Ltd. Agent
Person Patent Attorney - Ken Iro Torima
Patent Attorney Masatoshi MatsumotojI2 (A) (B)

Claims (1)

[Claims] (1) In a method for manufacturing an optical fiber supporting spacer in which a tensile strength wire is arranged in the center and a spacer body having a plurality of spiral grooves is formed on the outer periphery of the spacer body covered with thermoplastic resin, the tensile strength wire is placed in a crosshead die. For identification, the thermoplastic resin for the spacer main body and the colored resin for identification are merged at the tip of the crosshead die, and the tip is covered while rotating the outer periphery of the spacer. A method for manufacturing an optical fiber supporting spacer having a colored portion.