JP3103658B2 - Manufacturing method of straight single groove slot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a linear single-groove slot, and more particularly to a method of manufacturing a slot having a high-precision linear groove suitable for storing and carrying an optical fiber tape core wire or the like.

[0002]

2. Description of the Related Art Optical fiber cables are currently used as cables for subscribers of public communication, and will be used as cables to be connected to households in the future. Applications are expected. It is said that an ultrahigh-density optical fiber cable having a much higher density than the current one is required for use in such applications.

[0003] In such an ultra-high-density optical fiber cable, it is desirable to use a multi-core tape core wire arranged at a high density, and a cable is formed using this type of tape core wire. In this case, it is desirable to use a slot in which the cross-sectional area A of the concave groove accommodating the groove and the cross-sectional area B of the slot main body satisfy A / (A + B)> 30%. At this time, the shape of the slot groove is optimally rectangular (hereinafter referred to as square groove). Such slots are densely twisted and gathered around the tension member and used for a cable.

As a method for manufacturing such a slot, extrusion molding of a thermoplastic resin is generally employed, but there is one difficult problem. That is, high precision is required for the size of the square groove in which the optical fiber is housed, and it is necessary to secure it over the entire length of the slot.

[0005] In particular, in the case of a slot having a deep groove in which the ratio of the cross-sectional area occupied by the groove is very high and the groove depth is at least half the outer height of the slot, a stable groove shape is required. Was difficult to get.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a method of manufacturing a straight single-groove slot which can solve the above-mentioned problem of the shape. It is in.

[0007]

In order to achieve the above object, the present invention provides a tension member in which a crystalline thermoplastic resin constituting a slot body has a shrinkage rate at a softening point of 5% or less; a manufacturing method of a slot having one linear groove for accommodating responsible lifting the optical fiber tape comprising a thermoplastic resin, to below the melting point after extruding the crystalline thermoplastic resin around the tension member Cooling, or a first step of sizing while cooling, including a second step of sizing the molded product obtained in the first step at a temperature equal to or higher than the softening point of the crystalline thermoplastic resin and lower than the melting point. Features.

[0008] The tension member in the present invention is:
High-strength, high-modulus organic fibers (aromatic polyamide, aromatic polyester, polyamide, polyester, vinylon), inorganic fibers (glass fibers, carbon fibers, ceramic fibers, metal fibers), and their aggregates (fiber bundles, Twisted structures, braids, etc.), and FRP or FRTP filaments, thin metal wires, metal wire aggregates, etc. using the above-mentioned fibers and fiber aggregates as reinforcing fibers. A member that receives tension applied to the slot body during manufacturing, when slots are assembled into a cable, when a cable is laid, or when a cable is used.

The arrangement and configuration of the tension members in the slot are set in consideration of the tension applied to the slot body when the slot is manufactured, when the slots are assembled into a cable, when the cable is laid, and when the cable is used. Just do it.

The crystalline thermoplastic resin that can be used in the present invention is selected from various crystalline thermoplastic resins according to the performance required for the slot for supporting an optical fiber. And various polypropylenes, among which the low-temperature embrittlement temperature is −40 ° C. or less, and the flexural modulus at room temperature is 100%.
A resin of kg / mm ² or more is preferable, and high-density polyethylene, nylon 12, PBT (polyethylene butylene terephthalate) and the like are recommended.

The softening point of the resin in the present invention is
Refers to the value measured by JIS K7207 B method.
In the first step of the present invention, the tension member is supplied to an extruder, and after extruding the crystalline thermoplastic resin into a desired cross-sectional shape around the tension member, cooling to below the melting point, or sizing while cooling. A molded product having a linear storage groove is continuously obtained.

In the second step, the molded article having the linear accommodating groove obtained in the first step is heated to a temperature not lower than the softening point and not higher than the melting point of the thermoplastic resin, or is held by heating, so that the heat treatment effect is improved. In addition to sizing, the dimensional accuracy of the storage groove is improved and the change with time is reduced.

In the above manufacturing method, the first step and the second step do not always need to be performed continuously. The sizing of the present invention means that a solid corresponding to the shape and outer shape of the groove is brought into contact to make the shape uniform. In the sizing of a linear groove, a sizing key, a sizing pin and the like are inserted into the groove. A method is recommended.

[0014]

According to the method of manufacturing a linear single-groove slot of the present invention, the crystalline thermoplastic resin is extruded around the tension member and immediately cooled to the melting point or lower, or sizing while cooling, followed by the first step. A second step of sizing the molded article obtained in the above step at a temperature equal to or higher than the softening point of the crystalline thermoplastic resin and lower than the melting point.

When this manufacturing method is adopted, the crystalline thermoplastic resin undergoes heat shrinkage and softens with the progress of crystallization under the influence of the heating temperature. Therefore, by using a tension member having a shrinkage ratio of less than 5% in this temperature region and capable of adhering to or adhering to the crystalline thermoplastic resin, heat shrinkage can be suppressed and crystallinity can be increased, and at the same time, it can be easily achieved. Since the sizing can be performed, the slot for supporting the optical fiber can be obtained with good dimensional accuracy of the groove and little change over time.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments and comparative examples of the present invention will be described below in detail with reference to the accompanying drawings.

[0017] As shown the cross-sectional shape in Example 1 Figure 1 has a pair of side walls 1 on both sides, bound between the side walls 1 at the central portion, a connecting portion 2 which bottom exhibits an arc-shaped, cross section Is a slot formed by a substantially concave main body 3 and a tension member 4 embedded in the side wall 1, wherein a linear square groove 5 is provided between the side walls 1 as shown in FIG. Manufactured by In this manufacturing method, the target shape of the square groove 5 was 3.2 mm in width and 3.5 mm in depth.

The tension member 4 has W = 0.8 m.
m, T = 0.5mm square cross section, fiber content 63.9Vol
%, The surface is ionomer resin (Mitsui Petrochemical Co., Ltd.)
:: One-way glass fiber reinforced thermosetting resin (GFRP) wire treated with Chemipearl S100) is used as a crystalline thermoplastic resin for high-density polyethylene (Mitsui Petrochemical Co., Ltd.)
Manufactured by Hizex 6300HB). The target slot dimensions were as shown in FIG.

First, the tension member 4 is connected to the guide 6
The extruder 7 was supplied to a predetermined position of the extruder 7, and a high-density polyethylene in a molten state was extruded on an outer periphery of the extruder 7 with a deformed die, and was coated in a predetermined shape. Thereafter, the mixture was immediately introduced into the cooling tank 8 and sizing-cooled in the tank 8 using a sizing die having a predetermined shape (first step).

Next, immediately after passing through the heat treatment furnace 9 having a set temperature of 160 ° C., an inlet temperature of 100 ° C., and an outlet temperature of 110 ° C. of the hot air generator, the sizing device 10 uses a prismatic sizing key matching the groove size. While the groove sizing is performed, a Teflon rod having a diameter of 15 mm is brought into contact with the outer periphery of the connecting portion 2 to adjust the shape, and is taken up by a take-up machine 12 provided with dancer rolls 11 at a take-up speed of 5 m / min. The film was wound by the take-up machine 13 (second step).

The surface temperature of the slot at the outlet of the heat treatment furnace 9 was about 100.degree. As shown in FIG. 5, the slot having the obtained square groove 5 has a groove width of 3.74 to 3.80 mm immediately after production, and a groove width after a thermal test by leaving at 60 ° C. for 1 hour. There was no large change of 3.71 to 3.84 mm, and there was no concern about a change with time.
In addition, the adhesion between the tension member 4 and the slot main body 3 made of the thermoplastic resin is sufficient, and the overall heat shrinkage of the slot of the first embodiment is 0.30% (100 ° C. × 1 hour). The heat shrinkage was 1.5%, which was sufficiently smaller than the heat shrinkage of 1.5% when the tension member 4 was not provided. Further, the strength at 0.2% elongation of the slot of Example 1 was about 8 kg, which was a sufficient tensile strength in the slot manufacturing process.

Examples 2 to 5, Comparative Examples 1 to 6 Combinations of the tension member 4 and the crystalline thermoplastic resin, and the manufacturing conditions were set as shown in FIGS. A shaped slot was made.
The performance such as the groove size of the slot obtained under each manufacturing condition is also shown in FIGS.

As apparent from FIG. 6, in Comparative Example 1 in which the second step is omitted, and in Comparative Example 2 in which the slot surface temperature at the outlet of the heat treatment furnace 9 is lower than the softening point of the resin forming the main body 3, As a result of a heat test at 60 ° C. for 1 hour, the dimensional change of the groove was considerably large, and there was a possibility of a change with time.

In Comparative Example 3 in which the tension member 4 was not used, heat treatment and sizing could not be performed, the dimension of the groove changed greatly in a heat-heat test, and the heat shrinkage was large, which was not suitable for slot use. Met.

In both Example 4 and Comparative Example 4, an aromatic polyamide fiber (Kevlar 49 manufactured by DuPont) was used as the tension member 4 and nylon 12 (UBE3035U manufactured by Ube Industries, Ltd.) was used as the resin for forming the main body 3. Although it was used, in Comparative Example 4 in which no heat treatment was performed, the groove dimensional accuracy was lowered and was not suitable as a slot for an optical fiber cable.

In Comparative Example 5, as the tension member 4, the softening point (14
Polyester fiber (BHT-1000-250-P, manufactured by Teijin Limited) having a heat shrinkage of 9.5% at 5 ° C.).
A slot was produced in the same manner as in Example 4 except that the slot was used. According to the method obtained by this method, meandering occurred in the entire slot, and a ripple-like waving phenomenon also occurred on the inner wall portion of the groove, which was also unsuitable as an optical fiber cable slot.

Example 5 and Comparative Example 6 are manufacturing methods in which a slot having a sectional shape shown in FIG. 3 was manufactured. In this Example and Comparative Example, the side wall 1 was used as the tension member 4.
, An aromatic polyamide fiber (manufactured by DuPont: Kevlar 49) is arranged, and W = 1.50 mm, T
Using a unidirectional glass fiber reinforced thermosetting resin wire having a glass content of 63.3 Vol% of 0.5 mm and a polybutylene terephthalate resin (manufactured by Teijin Limited: C7
000 LN).

In Comparative Example 6 in which no heat treatment was performed, the groove width dimensional accuracy was reduced as in the case of Nylon 12, and was not suitable as an optical fiber cable slot. In addition, the cross-sectional shape of the single-groove slot to which the present invention can be applied is not limited to the one shown in the embodiment, for example,
As shown in FIG. 4, the bottom of the connecting portion 2 is flat (A), the bottom of the connecting portion 2 is flat and the opening side of the square groove 5 is widened, and the whole cross section is circular and concave at the center. Square groove 5
Can be suitably applied to those provided with.

[0029]

As described above in detail, according to the manufacturing method of the present invention, the optical fiber carrier having a groove having high dimensional accuracy and having no fear of aging is provided over the entire length. Slot is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a slot to which a manufacturing method according to the present invention is applied.

FIG. 2 is an explanatory view showing an example of a manufacturing method according to the present invention in the order of steps.

FIG. 3 is a sectional view of another slot to which the manufacturing method according to the present invention is applied;

FIG. 4 is a sectional view of still another slot to which the manufacturing method according to the present invention is applied.

FIG. 5 is a table showing the measurement results of the change over time in the slot dimensions of the slots obtained by the manufacturing conditions of the embodiments of the present invention and the manufacturing method of each embodiment.

FIG. 6 is a table showing the measurement results of the change over time in the groove dimension of the slot obtained by the manufacturing conditions of the comparative examples and the manufacturing method of each comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Side wall 2 Connecting part 3 Main part 4 Tension member 5 Square groove

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Shigehiro Matsuno 2-1-1 Yabuta Nishi, Gifu City Ube Nitto Kasei Co., Ltd. Gifu Research Institute (72) Inventor Kenji Kozuka 2-1-1 Yabuta Nishi, Gifu City Ube Nitto Kasei Co., Ltd. Gifu Research Laboratories (72) Inventor Masato Isobe 2-1-1, Yabuta Nishi, Gifu City Ube Nitto Kasei Co., Ltd. Gifu Research Laboratories (56) References JP-A-58-105110 (JP, A) JP-A-53-85854 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 47/00-47/96 G02B 6/44

Claims (1)

(57) [Claims] 1. A shrinkage at the softening point of the crystalline thermoplastic resin constituting the slot body and the tension member is not more than 5%, the crystalline thermoplastic resin and the optical fiber tapes or the like to be accommodated responsible for lifting the A method for manufacturing a slot having one linear groove, wherein the first step of extruding the crystalline thermoplastic resin around the tension member and then cooling or sizing while cooling to a melting point or less, Sizing the molded product obtained in one step at a temperature equal to or higher than the softening point of the crystalline thermoplastic resin and lower than the melting point.