JPH04147204A - Peeling type long-sized body - Google Patents

Abstract

PURPOSE:To allow the easy peeling of coating layers without flawing long-sized including bodies by providing diametral projections which decrease the thickness of another layer by biting into the recesses of this layer on the coating layer of a multilayered structure or the adjacent inside and outside layers of a tubular body. CONSTITUTION:A plastic optical fiber unit cable 10A consists of plural pieces of optical fiber units 18 twisted with optical fiber unit assemblies 12A which are the long-sized including bodies around an intervening material 16 and has >=2 layers of the coating layers 14A, 14B on a retaining winding layer 20. The inside layer 14A is extrusion molded by using the special extruding mouthpiece specially shaped to correspond to the projections 22A of this inside layer and the recesses 24A bitten with the projections 22B of the outside layer 14B. The outside layer 14B is molded by using an ordinary extruding mouthpiece. Shearing stresses are concentrated to the parts of the recesses 24A, 24B when the layer 14 of this cable 10A is pulled in the outer peripheral direction. The coating layers are thereby easily peeled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a peelable elongated body having a coating layer or a tubular body provided to cover an elongated inner envelope such as a cable body. It is.

[Prior art] - In m, an elongated body such as a cable has a coating layer provided on the outer periphery of the elongated inner envelope such as a cable body, or has a tubular body in which the elongated inner envelope is housed. .

In order to process the end portion of this type of elongated body, it is necessary to peel off the coating layer or the tubular body.

If the optical fiber is a long inner package or an optical fiber, if the optical fiber is damaged during terminal processing, the signal transmission characteristics will deteriorate significantly.
In particular, with plastic optical fibers, the crat part directly connected to signal transmission also serves as a coating layer on the optical fiber body, so if the surface of the optical fiber is damaged when removing the coating layer, it will be fatal to the transmission characteristics. It becomes a battle.

Therefore, when this coating layer is to be peeled off using a peeling tool, the coating layer must be removed with great care and with advanced techniques to avoid damaging the long inner package, resulting in low work efficiency. Ta.

For this reason, an elongated body having a peel-off type coating has been proposed, but the conventional peel-off type elongated body has a tear string such as a cotton thread provided between the elongated inner envelope and the coating layer. and
During peeling, the tear string is pulled in the radial direction to tear the coating layer.

[Invention or Problem to be Solved 11 However, the thickness of the covering layer is constant and large over the entire circumference, so when the tear string between the elongated inner envelope and the covering layer is pulled in the radial direction, In addition, since the coating layer is difficult to tear, it can only be applied when the diameter of the elongated inner body is 20 mm or less and the thickness of the coating layer is relatively thin, such as 1 mm or less.

Furthermore, when the covering layer or the tubular body has a multilayer structure of two or more layers, it is difficult to provide the tear string between the covering layer or the tubular body and the elongated inner body.

An object of the present invention is to avoid the above-mentioned drawbacks, to easily peel off a multilayered covering layer or a tubular body without using a peeling tool and without damaging the long inner body, and to It is an object of the present invention to provide a peelable elongated body that can be easily applied to a thick or large coating layer or a tubular body.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention is provided with a peeling mold that includes a covering layer or a tubular body that covers the elongated internal body, and the covering layer or the tubular body is made of multiple layers of 2M or more that do not fuse with each other. In the elongated body, the adjacent inner and outer layers of the covering layer or the tubular body each have radial protrusions that cut into recesses in the other layer to reduce the thickness of the other layer. This is a comprehensive offer.

1 Effect] In this way, in the coating layer of a multilayer structure that does not fuse with each other, or in the adjacent inner and outer layers of a tubular body, there is a radial direction that cuts into the recess of the other layer and reduces the thickness of the other layer. If the protrusion is provided, shearing stress will be concentrated in the thick or small indented area by pulling the coating layer or the tubular body in the outer circumferential direction, making it easy to peel off the coating layer or the tubular body. Since each dent is filled by the protrusion of the opposite layer, no voids are formed, and deformation of the covering layer or the tubular body and reduction in W1 mechanical strength can be suppressed.

[Example] An embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 shows an example of the peelable elongated body according to the present invention. The body is shown to be a plastic optical fiber unit cable IOA, and this plastic optical fiber unit cable IOA has a covering layer 14 covering an optical fiber unit assembly 12A, which is a long inner body. The optical fiber unit assembly 12A is
It consists of a plurality of optical fiber units 18 twisted together around an interposer 16, and a pressing layer 20 is provided around the optical fiber unit 18. In addition, coating layer 1
4 is made up of two or more multilayers 14A and 14B.

These inner and outer layers 14A, 14B are extruded from different materials at appropriate extrusion temperatures so that they do not melt into each other.

Adjacent inner and outer layers 14A, 14B of the covering layer 14 have radial protrusions 22A, 22B that cut into recesses of the opposing layer to reduce the thickness of the opposing layer, as shown. Reference numerals 24A and 24B in FIG.
B, 22A cut into the inner and outer layers 14A and 14, respectively.
B is a pre-formed dent.

The inner layer 14A of the coating layer 14 is extruded using a special extrusion die having a shape corresponding to the recess 24A into which the protrusions 22A and the protrusions 22B of the outer layer 14B bite, and the outer layer 14B is extruded using an ordinary extrusion die. The protrusions 22A and indentations 24 of the inner layer 14A may be extruded using
A correspondingly recess 24B and protrusion 22B
is formed.

This optical fiber unit cable IOA has a coating layer 14.
By pulling the cover M14 in the outer circumferential direction, the shear stress can be concentrated in the portions having small indentations 24A and 24B, and the coating M14 can be easily peeled off.

FIG. 2 shows another embodiment of the invention, in which:
The long body is a plastic optical fiber handle cable IO
It is shown whether it is B. This plastic optical fiber handle cable IOB includes a plastic optical fiber assembly 28 in which 16 plastic optical fibers 26 are assembled without twisting as a long inner package 12B, and a tubular shape formed by extrusion molding to house this assembly. It consists of a body 3o.

The tubular body 30 is composed of two or more multilayers 30A, 30B that do not fuse with each other, similar to the multilayer coating layer 14 of FIG. 1. Adjacent inner and outer layers 30A and 3 of the tubular body 30
0B are recesses 34 in mutually opposing layers as shown.
It has radial protrusions 32A and 32B that cut into B and 34A to reduce the thickness of the opposing layer. These inner and outer layers 3
0A and 30B are also extrusion-molded using a specially shaped inner layer extrusion die and a normally shaped outer layer extrusion die, similar to the coating layer 14 in FIG.

In this plastic optical fiber bundle cable IOB, the tubular body 30 can be easily stripped by pulling the tubular body 30 in the outer circumferential direction, concentrating shear stress on the thick wall or in the portion having a small dent.

Next, specific examples of the present invention will be described together with comparative examples (Specific Example 1
) Four plastic optical fibers with an outer diameter of 1.9 mm are formed by assembling nominal optical fibers made of polymethyl methacrylate resin with a core to produce a plastic optical fiber unit cable having the structure shown in Figure 1. After assembling the units by twisting them around the intervening part and pressing and winding them, the inner layer of the coating layer is formed by extrusion molding ethylene-vinyl acetate copolymer resin to a thickness of 0.5 mm. An outer layer was formed by extruding vinyl chloride to a thickness of 1 mm around the outer periphery. The thickness of the portion of the inner layer formed in this manner with the dent is 0.2 mm, which is set to two-fifths of the thickness of the portion of the inner layer other than the portion with the protrusion, and the thickness of the portion of the outer layer with the dent is 0.2 mm. Thickness is 0.4
mm, and was set to two-fifths of the thickness of the outer layer other than the portion having the protrusion.

The coating layer was removed during terminal processing of the plastic optical fiber unit cable obtained in this way, without using any tools other than cutting the coating, and the removal work was carried out for 1 m at a time.
I was able to do it in about 30 seconds. Furthermore, the number of times that the plastic optical fiber unit was damaged during this coating removal operation was 0 out of 20.

(Comparative Example 1) A plastic optical fiber unit cable having the same structure as the plastic optical fiber unit cable shown in FIG. 1 or having no dents or protrusions was manufactured. The materials and dimensions were exactly the same as in Example 1.

Since the coating layer of the plastic optical fiber unit cable thus obtained could not be removed by hand without using any tools other than cutting the coating, the coating layer was removed using a known cable cutter. Moreover, this work was performed for 120 seconds per 1 m, which was three times as long as in Example 1. Furthermore, in this case, the number of times that the optical fiber cord was damaged during coating removal work was 3 out of 20 times.

(Specific Example 2) In order to manufacture a plastic optical fiber bundle cable having the structure shown in Fig. 2, 16 nominally plastic optical fibers with an outer diameter of 0.5 mm were assembled without twisting and had an average outer diameter of 2.3 mm. A plastic optical fiber assembly was formed and a two-layer tubular body was formed to house the assembly. Note that polymethyl methacrylate was used as the core of this plastic optical fiber. The inner layer of this tubular body is formed by extruding low-density polyethylene to a thickness of 0.5 mm, and the outer layer is formed by extruding vinyl chloride to a thickness of 1.3 mm, and the outer diameter is 5.9 mm. Manufactured fiber bundle cables. The thickness of the portion of the inner layer formed in this manner that has the dent is 0.2 mm, which is set to two-fifths of the thickness of the portion of the inner layer other than the portion that has the protrusion, and the thickness of the portion of the outer layer that has the dent. The thickness was 0.5 mm, which was set to be two-fifths of the thickness of the outer layer other than the portion having the protrusions.

The coating layer was removed when processing the end of the plastic optical fiber handle cable obtained in this way, without using any tools other than cutting the coating, and the removal work was carried out for 1 m at a time.
I was able to do it in about 30 seconds. Furthermore, the number of times that the plastic optical fiber was damaged during this coating removal operation was 0 out of 20 times.

(Comparison Example 2) A plastic optical fiber handle cable having the same structure as the plastic optical fiber bundle cable shown in FIG. 2 or having no dents or protrusions was manufactured. The materials and dimensions were exactly the same as Variant Example 2.

Since the tubular body of the plastic optical fiber bundle cable obtained in this way could not be peeled off by hand without using any tools other than cutting after tearing, the coating layer was removed using a known cable cutter. Indeed, this work was carried out for 120 seconds per 1 meter, and specific example 2
It took four times as long. In addition, in this case, the number of times the plastic optical fiber was damaged during the tubular body removal work was 20.
It happened 5 times out of 5 times.

[Effects of the Invention] According to the present invention, as described above, the covering layer or the tubular body has a multilayer structure that does not fuse with each other and has protrusions that bite into the other layer, and each layer has one layer. Since the part has a recess formed so that its wall thickness is smaller than that of other parts, the part with the recess can be used to remove the coating layer or the tubular shape without using tools or damaging the elongated inner package. The body can be easily cut and peeled off, and the dents in each layer are filled by the protrusions of the other layer, preventing the formation of voids and reducing the deformation and mechanical strength of the covering layer or tubular body. Is there any real benefit to suppressing the decline?

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views of two embodiments of the peelable elongated body according to the present invention.
2B---One long inner inclusion body, 14---m-covering layer, 1
4A, 14B --- One inner and outer layer, 22A, 22B ---
-One protrusion, 24A, 24B---One dent, 30---
--One tubular body, 30A, 30B---One outer layer, 32
A, 32B----one protrusion, 34A, 34B----
Dent.

Claims (1)

[Claims] A peelable elongated body comprising a coating layer or a tubular body that covers the elongated inner capsule, and the coating layer or tubular body is composed of two or more layers that do not fuse with each other, and the coating layer or the tubular body Adjacent inner and outer layers each have radial protrusions that cut into recesses in the other layer to reduce the thickness of the other layer.