JPH01161203A - Plastic optical fiber sheet package - Google Patents

Abstract

PURPOSE:To smoothly form the title package as a sheet without being twisted or bent by mutually fusing the sheaths of plastic optical fibers having core sheath structure to form a sheet, specifying the interval between the width centers of respective sheets in the same winding layer and winding up the sheet around cheese at a fixed interval. CONSTITUTION:The sheaths of plastic optical fibers having core sheath structure are mutually fused to form a sheet and the sheets are wound up around the cheese at the fixed interval within the range of 1.1-2.0 times the fiber width W as the interval between the width centers of respective sheets in the same winding layer. Since the peeling strength of mutual constitutional fibers is high and the cheese shape is effective, an optical fiber sheet package with extremely high quality can be formed without generating wrinkles, twist, bend, etc., on the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to plastic optical fiber sheet packages. More specifically, the present invention relates to a package in which a plastic optical fiber sheet used for various sensor heads and displays is rolled up.

[Prior Art] Conventionally, optical fiber sheets have been used as elements of various sensor heads or for displays, and the range of applications is increasingly expanding.

Optical fiber sheets made by various manufacturing methods have been proposed. For example, an optical fiber sheet in which optical fibers are wound in a row on a drum and fixed, or an optical fiber sheet in which a large number of optical fibers from a yarn feeding creel are adjusted in diameter using a number of guides such as reeds, and then glued together. There are several types of optical fiber sheets.

On the other hand, a type of optical fiber sheet in which fibers are fused together during the spinning process of optical fibers was also developed in Japanese Patent Publication No. 39-2
No. 9646, Japanese Patent Publication No. 42-27585 or Japanese Patent Application Laid-open No. 8540-1985, Japanese Patent Application Laid-open No. 1987-1064
No. 5 and Japanese Patent Application Laid-Open No. 117202/1983.

JP-A-50-8540, JP-A-50-106
In the optical fiber sheet disclosed in Publication No. 45, the sheath components that are fused to each other are polymethyl methacrylate,
It may be glass. For this reason, the peeling strength between the component fibers is low and the flexibility is poor, resulting in an optical sheet with poor handling properties.

In addition, the optical sheet disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 60-117202 has a sheath component that is fused to each other and is made of fluorine-containing methacrylate, so the peeling strength of the constituent fibers from each other is poor and the flexibility is poor. It is.

In addition, the product form of plastic optical fiber sheets has traditionally been in the form of a so-called record roll, in which the sheets are rolled in a single row, but relatively thick sheets such as plastic optical fiber sheets are produced in long lengths. In addition, the high frequency of dotting results in poor productivity, resulting in high costs. Furthermore, since the package size increases, costs are high in terms of packaging and transportation.

Therefore, we use a winding device with a reciprocating traverse mechanism to make it compact like a cheese! However, the winding pitch of cheese wound onto a cylindrical bobbin by an internal winding device is difficult to regulate, and as a result, it is likely to wind up irregularly.

In other words, the sheets in the same winding layer are not arranged at uniform intervals and overlap irregularly, causing the sheets to twist or bend.
The wound surface was uneven and the winding shape was poor.

Optical fiber sheets that are twisted or bent in this way not only have a significantly inferior product quality, but also have problems in that they cannot be used in stacked applications or are undesirable in terms of optical transmission and other performance. Ta.

In addition, the problem with the sheeting method disclosed in the above publication is that the number of fibers is limited by the number of holes in the base, and the light transmittance of the optical fibers may deteriorate due to the arrangement of the ejection holes and the focusing method. Therefore, when the number of ejection holes is increased, the contact between the width regulating guide for focusing and both ends or the contact angle between the fibers becomes tighter, which tends to cause deterioration of the light transmittance, making it difficult to obtain a uniform optical fiber sheet. I can't.

In order to fuse optical fibers during the spinning process, it is common to use a gathering guide with a curvature, and by gathering and fusing under certain conditions, a uniform and smooth transparent It is possible to obtain an optical fiber sheet with excellent optical properties.

The gathering conditions include the number and arrangement of the discharge holes, the form, curvature, diameter, and mounting position of the gathering guide. If the contact angle is not appropriate, a uniform and smooth sheet will not be obtained, and the sheet will tear or wrinkle.

In addition, the fusion conditions include the type of polymer forming the fused part, the temperature of the cap, the temperature and speed of the cooling air, the viscosity of the polymer,
The distance of the gathering guide from the nozzle, the temperature and flow rate of gas or water as a refrigerant flowing inside the gathering guide, the wire diameter and take-up speed of the discharge wire, etc., and the fusion temperature determines the formation of the fused portion. It is several degrees Celsius or more higher than the melting point of the polymer. Moreover,
It is important from the viewpoint of translucency and uniformity of the sheet that the temperature be within a temperature range in which the polymer forming the core does not undergo softening or change in form.

Furthermore, no matter how uniform and smooth the fused optical fiber sheet is, if the winding method is inappropriate, □ twisting or bending may occur, making it impossible to obtain a smooth sheet, resulting in poor product quality. There are also performance issues such as translucency.

Therefore, in the past, the winding was done in one film, as in the case of record winding, but with relatively thick sheets such as plastic optical fibers, it was not possible to make the sheet longer, and the dotting frequency was high, reducing productivity. This leads to high costs, and the increased package size also increases costs in terms of packaging and transportation. Therefore, if it has a reciprocating traverse mechanism, it is necessary to wind it into a compact cheese-like shape using a winding device.
The pitch of cheese wound into a cylindrical bottle by an internal winding device is difficult to regulate, and as a result, the cheese tends to be rolled up irregularly. In other words, because the seeds in the same winding layer are not arranged at uniform intervals and overlap irregularly, the sheet may be twisted or bent, resulting in uneven winding surfaces and poor winding shapes. Ta.

[Problems to be Solved by the Invention] The present inventors have diligently studied the suitability conditions for sheet packaging, and have found that the distance between the center widths of the fibers of the sheet wound in the same layer on the winding surface is always constant. The present invention was achieved by finding that the fiber width is suitable within a certain range.

・The purpose of the present invention is to solve the above-mentioned drawbacks of conventional optical fiber sheets, to have high peeling strength between the component fibers, excellent flexibility and tensile strength, and to prevent twisting, bending, and winding of the surface. The object of the present invention is to provide a plastic optical fiber sheet package that has a good rolled shape with no edge height, edge drop, or unevenness, has a smooth sheet surface, and can be compactly rolled up into a cheese without deteriorating optical transmission properties.

Means for Solving Problem L] In order to achieve the above object, the present invention has the following configuration. That is, sheaths of plastic optical fibers having a core-sheath structure are fused together to form a sheet, and
This is a plastic optical fiber sheet package in which the width center distance P between sheets in the same winding layer is wound into a cheese at regular intervals within a range of 1.1 to 2.0 times the fiber width W.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a schematic perspective view showing an example of the plastic optical fiber sheet package of the present invention. The surface of this cheese has no selvage height, selvage drop, or unevenness, and has a good rolled shape, and as a sheet, it is smooth without twisting or bending.

A specific method for winding the fiber into a cheese-like package at regular intervals is to traverse the optical fiber sheet itself back and forth using a guide roller or the like, or to move the bobbin itself back and forth while the optical fiber sheet remains in a fixed position. The optical fiber sheet is wound onto a bobbin while being traversed by.

At this time, it is preferable that the free length between the point where the sheet leaves the guide roller contacting and rotating on the winding surface and the winding surface is always constant and 30 mm or less. Furthermore, it is also important that the distance between the width centers of the sheets wound in the same layer on the winding surface is within a certain range, and the relationship between these will be explained in detail with reference to FIG.

FIG. 2 shows a plastic optical fiber sheet in a cheese-like package with a good winding shape as described above at A1°A2. Bl,
It is a schematic diagram in which one side of cheese is developed based on the four points of B2.

In FIG. 2, 1 represents an optical fiber sheet and 2 represents a bobbin. In order for the cheese to have a good rolling shape with no edge height, edge drop, or unevenness on the winding surface, and to have a smooth sheet surface without twisting or bending due to the winding process, it is necessary to Although it is preferable that the sheets are uniformly arranged without gaps, it is difficult to maintain a good shape due to twisting, width fluctuations, and mechanical vibrations of the sheets themselves. Therefore,
As a result of intensive study by the present inventors regarding the appropriate conditions, it was found that the width center distance P of the sheets wound in the same winding layer on the winding surface is always constant, and the width center distance P of the sheets is always constant. Width W
It was found that the difference was 1.1 to 2.0 times that of the previous year.

In normal winding of a filament, a synchronization phenomenon between the number of revolutions and the traverse speed, which changes depending on the winding diameter, causes the filament to be wound in an overlapping band-like manner, called a ribbon. For this reason, the traverse speed is mechanically or electrically changed for each traverse or each reciprocation, but when winding a sheet-like material, it is necessary to always wind it at constant intervals regardless of changes in the winding diameter. It is preferable to use a constant wind ratio winding method in which the number of winds per traverse or one reciprocation is constant as the winding mechanism.

In such a constant wind ratio winding method, if the width center distance P between the sheets at the same winding amount on the bobbin is always within a certain relational range with respect to the sheet width W, the cheese obtained by winding the sheet The package has a good shape,
Moreover, the wound sheet also forms a smooth sheet without wrinkles or stiffness.

When P<1.1W, the sheets overlap each other due to the above-mentioned torsion, width fluctuation, and mechanical vibration of the sheets themselves, and moreover, there are many overlapping portions at both ends of the cheese.

As a result, both ends bulge, and narrow sheets in particular tend to be rolled.

On the other hand, P>2. ○ With W, the winding surface becomes rough and unevenness occurs.
A constant pitch cannot be maintained because the winding becomes unstable.

Furthermore, there is less overlap at both ends of the winding surface,
Rolling is likely to occur, resulting in poor cheese shape.

The following examples can be given as specific means for obtaining such a plastic optical fiber package that is wound at a constant pitch and has a good cheese-like winding shape.

That is, when the plastic optical fiber sheet is wound onto the bobbin by the guide roller or the bobbin's reciprocating traverse, the kite roller comes into rotational contact with the winding surface,
Moreover, by constantly contacting the winding surface with the - point as a fulcrum, it is not fixed in the winding diameter direction, and even if the winding diameter changes, the free length of the sheet from the guide roller to the winding surface is always constant. It can be regulated. In this case, it is important that the width of the guide roller at the portion through which the sheet passes is substantially the same as the width of the sheets 1 to 1.

In addition, the free length to maintain the predetermined pitch is 3Qmm.
The following is preferred.

FIG. 3 is a partially cutaway perspective view showing an example of a plastic optical fiber sheet rolled up into a package of the present invention.

The plastic optical fiber sheet consists of a core component polymer 3 and a sheath component polymer 4 surrounding it, and the sheath component polymers 4 are fused to each other. In this figure, D represents the diameter of the optical fiber.

Polymethyl methacrylate and its polymers having excellent transparency are generally used as the core component polymer.

On the other hand, as the sheath component polymer, a fluorine-based polymer having a lower refractive index than the core component polymer is generally used, but when polymethyl methacrylate is used as the core component polymer, the adhesion with it is significantly lower. Preferred are polyvinylidene fluoride and copolymers thereof, which have excellent properties such as spinnability and general mechanical properties. Polyvinylidene fluoride can easily have a larger fused area than other polymers, and has a high breaking stress, so it can have high tear strength. Therefore, it is suitable for a plastic optical fiber sheet, which requires that the fused portion between the fibers be strong and hard to break.

FIG. 4 is a diagram showing a method for measuring tear strength, which indicates fusion strength. Optical fiber sheet 1 is torn in advance at half its total width, attached to upper and lower chucks facing each other 100 mm apart, and pulled downward at a speed of 1.
The sample was torn at a speed of 0.00 mm/min, and the strength was defined as the tear strength. The tearing strength varies depending on the diameter D (mm) of the optical fibers constituting the optical fiber sheet 1, the fusion temperature, the fusion area determined by the viscosity of the polymer, and the breaking stress of the polymer, but it is practical as a plastic optical fiber sheet.・A tear strength of 20D (Ω) or more is required for the material to change.

18 The present invention will be explained below with reference to Examples.

[Example] Examples 1 to 5. Comparative Examples 1 and 2 Core: polymethyl methacrylate, clad: spun at 250° C., take-up speed 15 m/min, chimney cold air speed 0° 4 m/sec from a nozzle with serially arranged ejection holes.
Vinylidene fluoride/tetrafluoroethylene (8
0/20% by weight) Binary-13 = core-sheath composite spun fibers made of copolymer or perfluoromethacrylate are fused with a U-shaped collection guide set under the spinneret to form undrawn light. It was made into fiber sheet.

Subsequently, stretching and stretching are performed using a heating furnace equipped with a hot air circulation device.
It was heat treated and wound at 30 m/min.

The winding conditions are as follows: Using a paper tube with a body diameter of 82 m...φ,
It was wound at various pitches. The results are shown in Table-1.

The plastic optical fiber sheets according to the present invention of Examples 1 to 5 had high tear strength and fusion strength, and were high-quality sheets with no twists, wrinkles, or bends, and no cheese irregularities and a good rolled shape. .

On the other hand, as shown in Comparative Examples 1 and 2, in cases outside the range of the present invention, the tearing strength was low, and the shape of the cheese roll and the quality of the sheet were poor.

[Effects of the invention] The plastic optical fiber sheet package of the present invention has the following effects:
Eliminates the drawbacks of conventional plastic optical fiber sheet packages, and has high peeling strength between constituent fibers.
Because the cheese shape is good, the sheet is of extremely high quality with no wrinkles, twists, bends, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a plastic optical fiber sheet package of the present invention, and FIG. 2 is an A1°A2. FIG. 3 is a partially cutaway perspective view showing an example of the plastic optical fiber 1 used in the package of the present invention, and FIG. 4 shows a method for measuring tear strength. FIG. 1: Optical fiber sheet 2: Bobbin 3: Core component 4: Sheath component P: Width center distance between sheets W: Sheet width

Claims (1)

[Claims] (1) Sheaths of plastic optical fibers having a core-sheath structure are fused together to form a sheet, and the width center distance P between sheets in the same winding layer is 1 of the fiber width W.
．． A plastic optical fiber sheet package formed by winding up cheese at regular intervals within the range of 1 to 2.0 times.